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Background: Food craving refers to an intense desire to consume a specific kind of food of which chocolate is the most often craved one. It is this intensity and specificity that differentiates food craving from feelings of hunger. Although food craving and hunger often co-occur, an energy deficit is not a prerequisite for experiencing food craving, that is, it can also occur without being hungry. Food craving often precedes and predicts over- or binge eating which makes it a reasonable target in the treatment of eating disorders or obesity. One of the arguably most extensively validated measures for the assessment of food craving are the Food Cravings Questionnaires (FCQs), which measure food craving on a state (FCQ-S) and trait (FCQ-T) level. Specifically, the FCQ-S measures the intensity of current food craving whereas the FCQ-T measures the frequency of food craving experiences in general. The aims of the present thesis were to provide a German measure for the assessment of food craving and to investigate cognitive, behavioral, and physiological correlates of food craving. For this purpose, a German version of the FCQs was presented and its reliability and validity was evaluated. Using self-reports, relationships between trait food craving and dieting were examined. Cognitive-behavioral correlates of food craving were investigated using food-related tasks assessing executive functions. Psychophysiological correlates of food craving were investigated using event-related potentials (ERPs) in the electroencephalogram and heart rate variability (HRV). Possible intervention approaches to reduce food craving were derived from results of those studies.
Methods: The FCQs were translated into German and their psychometric properties and correlates were investigated in a questionnaire-based study (articles #1 & #2). The relationship between state and trait food craving with executive functioning was examined with behavioral tasks measuring working memory performance and behavioral inhibition which involved highly palatable food-cues (articles #3 & #4). Electrophysiological correlates of food craving were tested with ERPs during a craving regulation task (article #5). Finally, a pilot study on the effects of HRV-biofeedback for reducing food craving was conducted (article #6).
Results: The FCQs demonstrated high internal consistency while their factorial structure could only partially be replicated. The FCQ-T also had high retest-reliability which, expectedly, was lower for the FCQ-S. Validity of the FCQ-S was shown by positive relationships with current food deprivation and negative affect. Validity of the FCQ-T was shown by positive correlations with related constructs. Importantly, scores on the subscales of the FCQ-T were able to discriminate between non-dieters and successful and unsuccessful dieters (article #1). Furthermore, scores on the FCQ-T mediated the relationship between rigid dietary control strategies and low dieting success (article #2). With regard to executive functioning, high-calorie food-cues impaired working memory performance, yet this was independent of trait food craving and rarely related to state food craving (article #3). Behavioral disinhibition in response to high-calorie food-cues was predicted by trait food craving, particularly when participants were also impulsive (article #4). Downregulation of food craving by cognitive strategies in response to high-calorie food-cues increased early, but not later, segments of the Late Positive Potential (LPP) (article #5). Few sessions of HRV-biofeedback reduced self-reported food cravings and eating and weight concerns in high trait food cravers (article #6).
Conclusions: The German FCQs represent sound measures with good psychometric properties for the assessment of state and trait food craving. Although state food craving increases during cognitive tasks involving highly palatable food-cues, impairment of task performance does not appear to be mediated by current food craving experiences. Instead, trait food craving is associated with low behavioral inhibition in response to high-calorie food-cues, but not with impaired working memory performance. Future studies need to examine if trait food craving and, subsequently, food-cue affected behavioral inhibition can be reduced by using food-related inhibition tasks as a training. Current food craving and ERPs in response to food-cues can easily be modulated by cognitive strategies, yet the LPP probably does not represent a direct index of food craving. Finally, HRV-biofeedback may be a useful add-on element in the treatment of disorders in which food cravings are elevated. To conclude, the current thesis provided measures for the assessment of food craving in German and showed differential relationships between state and trait food craving with self-reported dieting behavior, food-cue affected executive functioning, ERPs and HRV-biofeedback. These results provide promising starting points for interventions to reduce food craving based on (1) food-cue-related behavioral trainings of executive functions, (2) cognitive craving regulation strategies, and (3) physiological parameters such as HRV-biofeedback.
Conflict Management
(2014)
Humans have a remarkable ability to plan ahead, set goals for the future and then to act accordingly. Unfortunately, this is not always the case. Everybody has experienced situations in which motivational urges like a tendency to drink another beer, or over-learned behavioral routines like driving on the right side of the road collide with ones´ goals. This tug of war between impulsive or habitual action tendencies and goal-directed actions is called a conflict.
Conflict is ubiquitous and comes in many different ways. Not surprisingly, the means to control conflict are diverse, too. Clearly, people can manage conflict in multiple ways: When expecting a conflict situation to occur in the future, one can recruit more effort to resolve the conflict, for instance by inhibiting unwanted urges or habits. Alternatively one can avoid the conflict situation and thereby circumvent possible failures to control habits and impulses. Furthermore, when currently facing a conflict, people can mobilize more effort to overcome the conflict. Alternatively they can withdraw from the conflict situation to minimize the risk of indulging in their impulses and habits.
To account for these different ways to master a conflict, the present thesis takes an initial step towards a characterization of the variability of control. To this aim, two dimensions of control will be identified that result from partially incompatible constraints on action control. These dimensions depict a trade-off between flexibility and stability and between anticipatory early selection and reactive late correction of control parameters. To describe how these control trade-offs interact and to explain how conflict is handled to ensure adaptation behavior, the conflict management framework is proposed. A corollary of this framework suggests that one strategy to control conflict comprises of a tendency to withdraw from a conflict situation.
The empirical part probed this behavioral response to conflict and tested whether participants withdraw from conflict situations. To approach this hypothesis, three series of experiments are presented that employ free choice paradigms, speeded response classification tasks and continuous movement tracking tasks to reveal withdrawal from conflict. Results show that conflict caused motivational avoidance tendencies (Experiment 1 &2), biased decision making away from conflict tasks (Experiment 3 & 5) and affected the execution of more complex courses of action (Experiment 6 & 7).
The results lend support for the proposed conflict management framework and provide the ground for a more thorough treatment of how the different conflict strategies can be integrated. As a first step, a connectionist model is presented that accounts for the simultaneous implementation of two conflict strategies observed in Experiments 3 – 5. The remainder of the present thesis analyses failures to integrate different conflict strategies. It is discussed how the conflict management framework can shed light on selected psychopathologies, inter-individual differences in control and break-downs of self-control.
The psychology of eating
(2013)
Renewal of fear is one form of relapse that occurs after successful therapy, resulting from an encounter with a feared object in a context different from the context of the exposure therapy. According to Bouton (1994), the return of fear, provoked by context change, indicates that the fear was not erased in the first place. More importantly, the return of fear indicates that during the exposure session a new association was learned that connected the feared object with “no fear”; yet, as Bouton further argues, this association is context dependent. Such dependence could explain effects like renewal. In a new context, the therapeutic association will not be expressed and thus will no longer inhibit the fear. The assumption that an association is context dependent has been tested and showed robust results (Balooch & Neumann, 2011; Siavash Bandarian Balooch, Neumann, & Boschen, 2012; Culver, Stoyanova, & Craske, 2011; Kim & Richardson, 2009; Neumann & Kitlertsirivatana, 2010). Research for the treatment of anxiety disorders, aiming to reduce fear and, more importantly, prevent relapse, is flourishing. There are several exposure protocols currently under investigation: multiple contexts exposure (MCE), which aims at reducing the return of fear due to renewal (e.g., Balooch & Neumann, 2011); prolonged exposure (PE), which aims at strengthening the inhibitory association during the extinction learning (e.g., Thomas, Vurbic, & Novak, 2009); and reconsolidation update (RU), which aims at “updating” the reconsolidation process by briefly exposing the CS+ before the actual extinction takes place (Schiller et al., 2010). So far, however, few clinical studies conducted on humans have investigated these novel treatment protocols, and as far as I know none has investigated the mechanisms of action behind these protocols with a human clinical sample. The present thesis has three main goals. The first is to demonstrate that exposure therapy in multiple contexts reduces the likelihood of renewal. The second is to examine the mechanisms contributing to the effect of MCE and the third is to shed light on the concept of context in the framework of the conditioning and extinction paradigm. To this end, three studies were conducted. The first study investigated the effect of MCE on renewal, the second and third studies examined working mechanisms of MCE. In the first study thirty spider-phobic participants were exposed four times to a virtual spider. The exposure trials were conducted either in one single context or in four different contexts. Finally, all participants completed both a virtual renewal test, with the virtual spider presented in a novel virtual context, and an in vivo behavioral avoidance test with a real spider. This study successfully demonstrated the efficacy of MCE on reducing renewal. Study 2 investigated the working mechanisms behind MCE by utilizing a differential conditioning paradigm and conducting the extinction in multiple contexts, targeting similar renewal attenuation as achieved in study 1. This was followed by two tests that attempted to reveal extinction-relevant associations like ones causing context inhibitory effects. This study had three main hypotheses: (1) The extinction context is associated with the exposure, and thus operates as a safety signal at some point during the extinction; it will therefore compete with the safety learning of the CS, leading to a decreased extinction effect on the CS if the extinction is conducted in only one context. (2) The elements (e.g., room color, furniture) of the extinction context are connected to the therapeutic association and therefore should serve as reminders of the extinction, causing a stronger fear inhibition when presented during a test. (3) Therapy process factors, according to emotional processing theory, determine the renewal effect (e.g., initial fear activation, and within-session and between-session activation are correlated with the strength of renewal). In this study, however, no differences between the groups at the renewal phase were observed, presumably because the extinction was too strong to enable a renewal of fear at the test phase conducted immediately following the extinction. This hence rendered the two inhibitory tests useless. Study 3 aimed at defining the concept of context in the conditioning and exposure framework. Study 3 utilized the phenomenon known as generalization decrement, whereby a conditioned response is reduced due to change in the environment. This allowed context similarity to be quantified. After an acquisition phase in one context, participants were tested in one of three contexts, two of which differed in only one dimension (configuration of objects vs. features). The third group was tested in the same context and served as control group. The goal was to show that both configuration and features play an important role in the definition of context. There was, however, no significant statistical difference between the groups at the test phases, likely because of context novelty effects (participants exposed to a new context following extinction in another context expected a second extinction phase, and thus demonstrated greater fear than expected in all three groups).
The aim of this study was both to investigate the influence of cognitive control on unconscious processing, and to investigate the influence of unconscious processing on cognitive control. At first, different mechanisms and accounts to explain unconscious priming are presented. Here, perceptual and motor processes, as well as stimulus-response learning, semantic categorization, and the action trigger account as theories to explain motor priming are discussed. Then, the issue of the potential limits of unconscious processing is presented. Findings that indicate that active current intentions and expertise modulate unconscious processing are illustrated. Subsequently, results that imply an influence of unconsciously presented stimuli that goes beyond motor processes are discussed, with a special focus on inhibition processes, orienting of attention, task set activation, and conflict adaptation. Then I present the results of my own empirical work. Experiment 1 shows that the effective processing of unconsciously presented stimuli depends on expertise, even when potentially confounding difference between the expert and novice groups are controlled. The results of Experiments 2 and 3 indicate that the intention to use particular stimuli is a crucial factor for the effectiveness of these stimuli when they are presented unconsciously. Additionally, these findings show that shifts of attention can be triggered by centrally presented masked arrow cues. Experiments 4 and 5 broaden these results to cue stimuli that are not inherently associated with a spatial meaning. The finding corroborate that typically endogenously controlled shifts of attention can also be induced by unconscious stimuli. Experiments 6 and 7 demonstrate that even a central cognitive control process like task set activation is not contingent on conscious awareness, but can in contrast be triggered through unconscious stimulation. Finally, these results are integrated and I discuss how the concept of cognitive control and the limits of unconscious processing may have to be reconsidered. Furthermore, potential future research possibilities in this field are presented.
In our current obesogenic environment, exposure to visual food-cues can easily lead to craving and overeating because short-term, pleasurable effects of food intake dominate over the anticipated long-term adverse effects such as weight gain and associated health problems. Here we contrasted these two conditions during food-cue presentation while acquiring event-related potentials (ERPs) and subjective craving ratings. Female participants (n = 25) were presented with either high-calorie (HC) or low-calorie (LC) food images under instructions to imagine either immediate (NOW) or long-term effects (LATER) of consumption. On subjective ratings for HC foods, the LATER perspective reduced cravings as compared to the NOW perspective. For LC foods, by contrast, craving increased under the LATER perspective. Early ERPs (occipital N1, 150-200 ms) were sensitive to food type but not to perspective. Late ERPs (late positive potential, LPP, 350-550 ms) were larger in the HC-LATER condition than in all other conditions, possibly indicating that a cognitive focus on negative long-term consequences induced negative arousal. This enhancement for HC-LATER attenuated to the level of the LC conditions during the later slow wave (550-3000 ms), but amplitude in the HC-NOW condition was larger than in all other conditions, possibly due to a delayed appetitive response. Across all conditions, LPP amplitudes were positively correlated with self-reported emotional eating. In sum, results reveal that regulation effects are secondary to an early attentional analysis of food type and dynamically evolve over time. Adopting a long-term perspective on eating might promote a healthier food choice across a range of food types.
Alerting signals often serve to reduce temporal uncertainty by predicting the time of stimulus onset. The resulting response time benefits have often been explained by facilitated translation of stimulus codes into response codes on the basis of established stimulus-response (S-R) links. In paradigms of masked S-R priming alerting signals also modulate response activation processes triggered by subliminally presented prime stimuli. In the present study we tested whether facilitation of visuo-motor translation processes due to alerting signals critically depends on established S-R links. Alerting signals resulted in significantly enhanced masked priming effects for masked prime stimuli that included and that did not include established S-R links fi.e., target vs. novel primes). Yet, the alerting-priming interaction was more pronounced for target than for novel primes. These results suggest that effects of alerting signals on masked priming are especially evident when S-R links between prime and target exist. At the same time, an alerting-priming interaction also for novel primes suggests that alerting signals also facilitate stimulus-response translation processes when masked prime stimuli provide action-trigger conditions in terms of programmed S-R links.
This paper addresses the question of how the brain maintains a probabilistic body state estimate over time from a modeling perspective. The neural Modular Modality Frame (nMMF) model simulates such a body state estimation process by continuously integrating redundant, multimodal body state information sources. The body state estimate itself is distributed over separate, but bidirectionally interacting modules. nMMF compares the incoming sensory and present body state information across the interacting modules and fuses the information sources accordingly. At the same time, nMMF enforces body state estimation consistency across the modules. nMMF is able to detect conflicting sensory information and to consequently decrease the influence of implausible sensor sources on the fly. In contrast to the previously published Modular Modality Frame (MMF) model, nMMF offers a biologically plausible neural implementation based on distributed, probabilistic population codes. Besides its neural plausibility, the neural encoding has the advantage of enabling (a) additional probabilistic information flow across the separate body state estimation modules and (b) the representation of arbitrary probability distributions of a body state. The results show that the neural estimates can detect and decrease the impact of false sensory information, can propagate conflicting information across modules, and can improve overall estimation accuracy due to additional module interactions. Even bodily illusions, such as the rubber hand illusion, can be simulated with nMMF. We conclude with an outlook on the potential of modeling human data and of invoking goal-directed behavioral control.
Why are you looking like that? How the context influences evaluation and processing of human faces
(2013)
Perception and evaluation of facial expressions are known to be heavily modulated by emotional features of contextual information. Such contextual effects, however, might also be driven by non-emotional aspects of contextual information, an interaction of emotional and non-emotional factors, and by the observers’ inherent traits. Therefore, we sought to assess whether contextual information about self-reference in addition to information about valence influences the evaluation and neural processing of neutral faces. Furthermore, we investigated whether social anxiety moderates these effects. In the present functional magnetic resonance imaging (fMRI) study, participants viewed neutral facial expressions preceded by a contextual sentence conveying either positive or negative evaluations about the participant or about somebody else. Contextual influences were reflected in rating and fMRI measures, with strong effects of self-reference on brain activity in the medial prefrontal cortex and right fusiform gyrus. Additionally, social anxiety strongly affected the response to faces conveying negative, self-related evaluations as revealed by the participants’ rating patterns and brain activity in cortical midline structures and regions of interest in the left and right middle frontal gyrus. These results suggest that face perception and processing are highly individual processes influenced by emotional and non-emotional aspects of contextual information and further modulated by individual personality traits.
Objective
Brain-computer interfaces (BCIs) provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)) or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball.
Methods
Forty healthy participants performed an electroencephalography (EEG) based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude.
Results
Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy.
Conclusions
Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection.
Significance
Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.
Motivation moderately influences brain–computer interface (BCI) performance in healthy subjects when monetary reward is used to manipulate extrinsic motivation. However, the motivation of severely paralyzed patients, who are potentially in need for BCI, could mainly be internal and thus, an intrinsic motivator may be more powerful. Also healthy subjects who participate in BCI studies could be internally motivated as they may wish to contribute to research and thus extrinsic motivation by monetary reward would be less important than the content of the study. In this respect, motivation could be defined as “motivation-to-help.” The aim of this study was to investigate, whether subjects with high motivation for helping and who are highly empathic would perform better with a BCI controlled by event-related potentials (P300-BCI). We included N = 20 healthy young participants naïve to BCI and grouped them according to their motivation for participating in a BCI study in a low and highly motivated group. Motivation was further manipulated with interesting or boring presentations about BCI and the possibility to help patients. Motivation for helping did neither influence BCI performance nor the P300 amplitude. Post hoc, subjects were re-grouped according to their ability for perspective taking. We found significantly higher P300 amplitudes on parietal electrodes in participants with a low ability for perspective taking and therefore, lower empathy, as compared to participants with higher empathy. The lack of an effect of motivation on BCI performance contradicts previous findings and thus, requires further investigation. We speculate that subjects with higher empathy who are good perspective takers with regards to patients in potential need of BCI, may be more emotionally involved and therefore, less able to allocate attention on the BCI task at hand.
In social interaction, the facial expression of an opponent contains information that may influence the interaction. We asked whether facial expression affects decision-making in the ultimatum game. In this two-person game, the proposer divides a sum of money into two parts, one for each player, and then the responder decides whether to accept the offer or reject it. Rejection means that neither player gets any money. Results of a large-sample study support our hypothesis that offers from proposers with a smiling facial expression are more often accepted, compared to a neutral facial expression. Moreover, we found lower acceptance rates for offers from proposers with an angry facial expression.
We examined whether a voluntary response becomes associated with the (affective) meaning of intended response effects. Four experiments revealed that coupling a keypress with positive or negative consequences produces affective compatibility effects when the keypress has to be executed in response to positively or negatively evaluated stimulus categories. In Experiment 1, positive words were evaluated faster with a keypress that turned the words ON (versus OFF), whereas negative words were evaluated faster with a keypress that turned the words OFF (versus ON). Experiment 2 showed that this compatibility effect is reversed if an aversive tone is turned ON and OFF with keypresses. Experiment 3 revealed that keypresses acquire an affective meaning even when the association between the responses and their effects is variable and intentionally reconfigured before each trial. Experiment 4 used affective response effects to assess implicit ingroup favoritism, showing that the measure is sensitive to the valence of categories and not to the valence of exemplars. Results support the hypothesis that behavioral reactions become associated with the affective meaning of the intended response goal, which has important implications for the understanding and construction of implicit attitude measures.
Relief from pain is positively valenced and entails reward-like properties. Notably, stimuli that became associated with pain relief elicit reward-like implicit responses too, but are explicitly evaluated by humans as aversive. Since the unpredictability of pain makes pain more aversive, this study examined the hypotheses that the predictability of pain also modulates the valence of relief-associated stimuli. In two studies, we presented one conditioned stimulus \((_{FORWARD}CS+)\) before a painful unconditioned stimulus (US), another stimulus \((_{BACKWARD}CS+)\) after the painful US, and a third stimulus (CS−) was never associated with the US. In Study 1, \(_{FORWARD}CS+\) predicted half of the USs while the other half was delivered unwarned and followed by \(_{BACKWARD}CS+\). In Study 2, all USs were predicted by \(_{FORWARD}CS+\) and followed by \(_{BACKWARD}CS+\). In Study 1 both \(_{FORWARD}CS+\) and \(_{BACKWARD}CS+\) were rated as negatively valenced and high arousing after conditioning, while \(_{BACKWARD}CS+\) in Study 2 acquired positive valence and low arousal. Startle amplitude was significantly attenuated to \(_{BACKWARD}CS+\) compared to \(_{FORWARD}CS+\) in Study 2, but did not differ among CSs in Study 1. In summary, predictability of aversive events reverses the explicit valence of a relief-associated stimulus.
Introduction
There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task.
Methods
We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects.
Results
Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed.
Conclusions
Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.
This study examined the impact of three clinical psychological variables (non-pathological levels of depression and anxiety, as well as experimentally manipulated mood) on fat and taste perception in healthy subjects. After a baseline orosensory evaluation, ‘sad’, ‘happy’ and ‘neutral’ video clips were presented to induce corresponding moods in eighty participants. Following mood manipulation, subjects rated five different oral stimuli, appearing sweet, umami, sour, bitter, fatty, which were delivered at five different concentrations each. Depression levels were assessed with Beck’s Depression Inventory (BDI) and anxiety levels were assessed via the Spielberger’s STAI-trait and state questionnaire. Overall, subjects were able to track the concentrations of the stimuli correctly, yet depression level affected taste ratings. First, depression scores were positively correlated with sucrose ratings. Second, subjects with depression scores above the sample median rated sucrose and quinine as more intense after mood induction (positive, negative and neutral). Third and most important, the group with enhanced depression scores did not rate low and high fat stimuli differently after positive or negative mood induction, whereas, during baseline or during the non-emotional neutral condition they rated the fat intensity as increasing with concentration. Consistent with others’ prior observations we also found that sweet and bitter stimuli at baseline were rated as more intense by participants with higher anxiety scores and that after positive and negative mood induction, citric acid was rated as stronger tasting compared to baseline. The observation that subjects with mild subclinical depression rated low and high fat stimuli similarly when in positive or negative mood is novel and likely has potential implications for unhealthy eating patterns. This deficit may foster unconscious eating of fatty foods in sub-clinical mildly depressed populations.
The serotonin (5-HT) and neuropeptide S (NPS) systems are discussed as important genetic modulators of fear and sustained anxiety contributing to the etiology of anxiety disorders. Sustained anxiety is a crucial characteristic of most anxiety disorders which likely develops through contextual fear conditioning. This study investigated if and how genetic alterations of the 5-HT and the NPS systems as well as their interaction modulate contextual fear conditioning; specifically, function polymorphic variants in the genes coding for the 5-HT transporter (5HTT) and the NPS receptor (NPSR1) were studied. A large group of healthy volunteers was therefore stratified for 5HTTLPR (S+ vs. LL carriers) and NPSR1 rs324981 (T+ vs. AA carriers) polymorphisms resulting in four genotype groups (S+/T+, S+/AA, LL/T+, LL/AA) of 20 participants each. All participants underwent contextual fear conditioning and extinction using a virtual reality (VR) paradigm. During acquisition, one virtual office room (anxiety context, CXT+) was paired with an unpredictable electric stimulus (unconditioned stimulus, US), whereas another virtual office room was not paired with any US (safety context, CXT−). During extinction no US was administered. Anxiety responses were quantified by fear-potentiated startle and ratings. Most importantly, we found a gene × gene interaction on fear-potentiated startle. Only carriers of both risk alleles (S+/T+) exhibited higher startle responses in CXT+ compared to CXT−. In contrast, anxiety ratings were only influenced by the NPSR1 polymorphism with AA carriers showing higher anxiety ratings in CXT+ as compared to CXT−. Our results speak in favor of a two level account of fear conditioning with diverging effects on implicit vs. explicit fear responses. Enhanced contextual fear conditioning as reflected in potentiated startle responses may be an endophenotype for anxiety disorders.
Empirical evidence suggests that words are powerful regulators of emotion processing. Although a number of studies have used words as contextual cues for emotion processing, the role of what is being labeled by the words (i.e., one's own emotion as compared to the emotion expressed by the sender) is poorly understood. The present study reports results from two experiments which used ERP methodology to evaluate the impact of emotional faces and self- vs. sender-related emotional pronoun-noun pairs (e.g., my fear vs. his fear) as cues for emotional face processing. The influence of self- and sender-related cues on the processing of fearful, angry and happy faces was investigated in two contexts: an automatic (experiment 1) and intentional affect labeling task (experiment 2), along with control conditions of passive face processing. ERP patterns varied as a function of the label's reference (self vs. sender) and the intentionality of the labeling task (experiment 1 vs. experiment 2). In experiment 1, self-related labels increased the motivational relevance of the emotional faces in the time-window of the EPN component. Processing of sender-related labels improved emotion recognition specifically for fearful faces in the N170 time-window. Spontaneous processing of affective labels modulated later stages of face processing as well. Amplitudes of the late positive potential (LPP) were reduced for fearful, happy, and angry faces relative to the control condition of passive viewing. During intentional regulation (experiment 2) amplitudes of the LPP were enhanced for emotional faces when subjects used the self-related emotion labels to label their own emotion during face processing, and they rated the faces as higher in arousal than the emotional faces that had been presented in the “label sender's emotion” condition or the passive viewing condition. The present results argue in favor of a differentiated view of language-as-context for emotion processing.
This paper describes a case study with a patient in the classic locked-in state, who currently has no means of independent communication. Following a user-centered approach, we investigated event-related potentials (ERP) elicited in different modalities for use in brain-computer interface (BCI) systems. Such systems could provide her with an alternative communication channel. To investigate the most viable modality for achieving BCI based communication, classic oddball paradigms (1 rare and 1 frequent stimulus, ratio 1:5) in the visual, auditory and tactile modality were conducted (2 runs per modality). Classifiers were built on one run and tested offline on another run (and vice versa). In these paradigms, the tactile modality was clearly superior to other modalities, displaying high offline accuracy even when classification was performed on single trials only. Consequently, we tested the tactile paradigm online and the patient successfully selected targets without any error. Furthermore, we investigated use of the visual or tactile modality for different BCI systems with more than two selection options. In the visual modality, several BCI paradigms were tested offline. Neither matrix-based nor so-called gaze-independent paradigms constituted a means of control. These results may thus question the gaze-independence of current gaze-independent approaches to BCI. A tactile four-choice BCI resulted in high offline classification accuracies. Yet, online use raised various issues. Although performance was clearly above chance, practical daily life use appeared unlikely when compared to other communication approaches (e.g., partner scanning). Our results emphasize the need for user-centered design in BCI development including identification of the best stimulus modality for a particular user. Finally, the paper discusses feasibility of EEG-based BCI systems for patients in classic locked-in state and compares BCI to other AT solutions that we also tested during the study.
Brain-computer interfaces (BCIs) provide a non-muscular communication channel for persons with severe motor impairments. Previous studies have shown that the aptitude with which a BCI can be controlled varies from person to person. A reliable predictor of performance could facilitate selection of a suitable BCI paradigm. Eleven severely motor impaired participants performed three sessions of a P300 BCI web browsing task. Before each session auditory oddball data were collected to predict the BCI aptitude of the participants exhibited in the current session. We found a strong relationship of early positive and negative potentials around 200 ms (elicited with the auditory oddball task) with performance. The amplitude of the P2 (r = −0.77) and of the N2 (r = −0.86) had the strongest correlations. Aptitude prediction using an auditory oddball was successful. The finding that the N2 amplitude is a stronger predictor of performance than P3 amplitude was reproduced after initially showing this effect with a healthy sample of BCI users. This will reduce strain on the end-users by minimizing the time needed to find suitable paradigms and inspire new approaches to improve performance.
Background
The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated.
Results
Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses.
Conclusions
Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.
Objective: Brain-computer interface (BCI) provide a non-muscular communication channel for patients with impairments of the motor system. A significant number of BCI users is unable to obtain voluntary control of a BCI-system in proper time. This makes methods that can be used to determine the aptitude of a user necessary.
Methods: We hypothesized that integrity and connectivity of involved white matter connections may serve as a predictor of individual BCI-performance. Therefore, we analyzed structural data from anatomical scans and DTI of motor imagery BCI-users differentiated into high and low BCI-aptitude groups based on their overall performance.
Results: Using a machine learning classification method we identified discriminating structural brain trait features and correlated the best features with a continuous measure of individual BCI-performance. Prediction of the aptitude group of each participant was possible with near perfect accuracy (one error).
Conclusions: Tissue volumetric analysis yielded only poor classification results. In contrast, the structural integrity and myelination quality of deep white matter structures such as the Corpus Callosum, Cingulum, and Superior Fronto-Occipital Fascicle were positively correlated with individual BCI-performance.
Significance: This confirms that structural brain traits contribute to individual performance in BCI use.
Objective: Brain-computer interfaces (BCIs) provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)) or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. Methods: Forty healthy participants performed an electroencephalography (EEG) based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. Results: Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. Conclusions: Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. Significance: Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.
Body image disturbances are core symptoms of eating disorders (EDs). Recent evidence suggests that changes in body image may occur prior to ED onset and are not restricted to in-vivo exposure (e.g. mirror image), but also evident during presentation of abstract cues such as body shape and weight-related words. In the present study startle modulation, heart rate and subjective evaluations were examined during reading of body words and neutral words in 41 student female volunteers screened for risk of EDs. The aim was to determine if responses to body words are attributable to a general negativity bias regardless of ED risk or if activated, ED relevant negative body schemas facilitate priming of defensive responses. Heart rate and word ratings differed between body words and neutral words in the whole female sample, supporting a general processing bias for body weight and shape-related concepts in young women regardless of ED risk. Startle modulation was specifically related to eating disorder symptoms, as was indicated by significant positive correlations with self-reported body dissatisfaction. These results emphasize the relevance of examining body schema representations as a function of ED risk across different levels of responding. Peripheral-physiological measures such as the startle reflex could possibly be used as predictors of females’ risk for developing EDs in the future.
Background: Nicotine addiction is the most prevalent type of drug addiction that has been described as a cycle of spiraling dysregulation of the brain reward systems. Imaging studies have shown that nicotine addiction is associated with abnormal function in prefrontal brain regions that are important for cognitive emotion regulation. It was assumed that addicts may perform less well than healthy nonsmokers in cognitive emotion regulation tasks. The primary aims of this thesis were to investigate emotional responses to natural rewards among smokers and nonsmokers and to determine whether smokers differ from nonsmokers in cognitive regulation of positive and negative emotions. To address these aims, two forms of appraisal paradigms (i.e., appraisal frame and reappraisal) were applied to compare changes in emotional responses of smokers with that of nonsmokers as a function of appraisal strategies. Experiment 1: The aim of the first experiment was to evaluate whether and how appraisal frames preceding positive and negative picture stimuli affect emotional experience and facial expression of individuals. Twenty participants were exposed to 125 pairs of auditory appraisal frames (either neutral or emotional) followed by picture stimuli reflecting five conditions: unpleasant-negative, unpleasant-neutral, pleasant-positive, pleasant-neutral and neutral-neutral. Ratings of valence and arousal as well as facial EMG activity over the corrugator supercilii and the zygomaticus major were measured simultaneously. The results indicated that appraisal frames could alter both subjective emotional experience and facial expressions, irrespective of the valence of the pictorial stimuli. These results suggest and support that appraisal frame is an efficient paradigm in regulation of multi-level emotional responses. 8 Experiment 2: The second experiment applied the appraisal frame paradigm to investigate how smokers differ from nonsmokers on cognitive emotion regulation. Sixty participants (22 nonsmokers, 19 nondeprived smokers and 19 12-h deprived smokers) completed emotion regulation tasks as described in Experiment 1 while emotional responses were concurrently recorded as reflected by self-ratings and psychophysiological measures (i.e., facial EMG and EEG). The results indicated that there was no group difference on emotional responses to natural rewards. Moreover, nondeprived smokers and deprived smokers performed as well as nonsmokers on the emotion regulation task. The lack of group differences in multiple emotional responses (i.e., self-reports, facial EMG activity and brain EEG activity) suggests that nicotine addicts have no deficit in cognitive emotion regulation of natural rewards via appraisal frames. Experiment 3: The third experiment aimed to further evaluate smokers’ emotion regulation ability by comparing performances of smokers and nonsmokers in a more challenging cognitive task (i.e., reappraisal task). Sixty-five participants (23 nonsmokers, 22 nondeprived smokers and 20 12-h deprived smokers) were instructed to regulate emotions by imagining that the depicted negative or positive scenario would become less negative or less positive over time, respectively. The results showed that nondeprived smokers and deprived smokers responded similarly to emotional pictures and performed as well as nonsmokers in down-regulating positive and negative emotions via the reappraisal strategy. These results indicated that nicotine addicts do not have deficit in emotion regulation using cognitive appraisal strategies. In sum, the three studies consistently revealed that addicted smokers were capable to regulate emotions via appraisal strategies. This thesis establishes the groundwork for therapeutic use of appraisal instructions to cope with potential self-regulation failures in nicotine addicts.
The perception of pain can be modulated by a variety of factors such as biological/pharmacological treatments as well as potent cognitive and emotional manipulations. Placebo and nocebo effects are among the most prominent examples for such manipulations. Placebo and nocebo manipulations cause reliable psychological and physiological changes, although the administered agent or treatment is inert. The present dissertation aimed at investigating the role of cognitive and emotional influences in the generation of placebo and nocebo effects on pain perception. In addition, the feasibility of solely psychological placebo manipulations to alter the perception of pain was tested.
Two commonly discussed preconditions for the generation of placebo and nocebo effects are prior experiences (i.e., past encounter of drug effects) and expectations (i.e., positive or negative attitudes towards an intervention). So far, research on placebo and nocebo effects relied on the administration of sham interventions, which resembled medical treatments like inert pills, creams or injections. However, such experimental procedures deal with confounds due to earlier experiences and expectations resulting from the individual’s history with medical interventions. Accordingly, the implementation of a placebo manipulation that is completely new to an individual, seems necessary to disentangle the contribution of experience and expectation for the induction of placebo and nocebo effects.
To this end, in Experiment 1 the level of experience and expectation regarding a placebo-nocebo treatment was stepwise manipulated across three different experimental groups. To avoid any resemblances to earlier experiences and individual expectations, a mere psychological placebo-nocebo treatment was chosen that was new to all participants. They were instructed that visual black and white stripe patterns had been found to reliably alter the perception of pain. One group of participants received only the placebo-nocebo instruction (expectation), a second group experienced a placebo-nocebo treatment within a conditioning phase (experience) but no instruction, and a third group received the combination of both that is a placebo-nocebo instruction and a placebo-nocebo conditioning (experience + expectation).
It was shown that only the experience + expectation group revealed significantly higher pain ratings and physiological responses during nocebo, compared to placebo trials of the succeeding test phase. These findings demonstrate that the induction of a mere psychological placebo-nocebo effect on pain is in principle possible. Most important, results indicate that such effects most likely rely on both, a positive treatment experience, due to the encounter of an effective intervention (placebo conditioning), and a positive expectation about the intervention (placebo instruction).Besides experience and expectation, the current mood state has been shown to modulate pain and to impact the induction of placebo and nocebo effects. In this vein it has been demonstrated that placebo effects come along with positive affect, while nocebo effects often occur together with elevated feelings of anxiety. To clarify the interaction of emotions and placebo-nocebo manipulations on pain perception, in Experiment 2 the paradigm of Experiment 1 was modified. Instead of black and white stripe patterns, positive and negative emotional pictures were presented, which either cued pain increase (nocebo) or pain decrease (placebo). Two experimental groups were compared, which differed with regard to the instructed contingency of positive pictures serving as placebo and negative pictures serving as nocebo cues or vice versa (congruent vs. incongruent). Results indicate that the differentiation of placebo and nocebo trials (behaviorally and physiologically) was more pronounced for the congruent compared to the incongruent group. However, in the incongruent group, affective pain ratings were also significantly higher for nocebo (positive pictures) than placebo (negative pictures) trials, similar to the congruent group. These findings demonstrate that a placebo-nocebo manipulation is capable to dampen and even reverse the originally pain augmenting effect of negative emotions.
The results of Experiment 2 were further corroborated in Experiment 3, when the design was adapted to the fMRI scanner, and again a congruent and an incongruent experimental group were compared. Behavioral, physiological and neurophysiological markers of pain processing revealed a differentiation between nocebo and placebo conditions that was present irrespective of the experimental group. In addition, the fMRI analysis revealed an increased engagement of prefrontal areas for the incongruent group only, supposedly reflecting the reinterpretation or appraisal process when positive pictures were cueing negative outcomes.
Taken together, the results of the present studies showed (a) that it is possible to induce a placebo-nocebo effect on pain solely by a psychological manipulation, (b) that both, prior experiences and positive expectation, are necessary preconditions for this placebo-nocebo effect, (c) that the impact of negative emotion on pain can be dampened and even reversed by placebo-nocebo manipulations, and (d) that most likely a cognitive top-down process is crucial for the induction of (psychological) placebo-nocebo effects.
These results significantly enhance our understanding of psychological mechanisms involved in the induction of placebo-nocebo effects. Further, a fruitful foundation for future studies is provided, which will need to determine the contributions of primarily nocebo or placebo responses mediating the effects as demonstrated in the present studies. In a long-term perspective, the present findings may also help to exploit placebo effects and prevent from nocebo effect in clinical contexts by further elucidating crucial psychological factors that contribute to the placebo and nocebo response.
Objective: Brain Computer Interfaces (BCI) provide a muscle independent interaction channel making them particularly valuable for individuals with severe motor impairment. Thus, different BCI systems and applications have been proposed as assistive technology (AT) solutions for such patients. The most prominent system for communication utilizes event-related potentials (ERP) obtained from the electroencephalogram (EEG) to allow for communication on a character-by-character basis. Yet in their current state of technology, daily life use cases of such systems are rare. In addition to the high EEG preparation effort, one of the main reasons is the low information throughput compared to other existing AT solutions. Furthermore, when testing BCI systems in patients, a performance drop is usually observed compared to healthy users. Patients often display a low signal-to-noise ratio of the recorded EEG and detection of brain responses may be aggravated due to internally (e.g. spasm) or externally induced artifacts (e.g. from ventilation devices). Consequently, practical BCI systems need to cope with mani-fold inter-individual differences. Whilst these high demands lead to increasing complexity of the technology, daily life use of BCI systems requires straightforward setup including an easy-to-use graphical user interface that nonprofessionals can handle without expert support. Research questions of this thesis: This dissertation project aimed at bringing forward BCI technology toward a possible integration into end-users' daily life. Four basic research questions were addressed: (1) Can we identify performance predictors so that we can provide users with individual BCI solutions without the need of multiple, demanding testing sessions? (2) Can we provide complex BCI technology in an automated, user-friendly and easy-to-use manner, so that BCIs can be used without expert support at end-users' homes? (3) How can we account for and improve the low information transfer rates as compared to other existing assistive technology solutions? (4) How can we prevent the performance drop often seen when bringing BCI technology that was tested in healthy users to those with severe motor impairment? Results and discussion: (1) Heart rate variability (HRV) as an index of inhibitory control (i.e. the ability to allocate attention resources and inhibit distracting stimuli) was significantly related to ERP-BCI performance and accounted for almost 26% of variance. HRV is easy to assess from short heartbeat recordings and may thus serve as a performance predictor for ERP-BCIs. Due to missing software solutions for appropriate processing of artifacts in heartbeat data (electrocardiogram and inter-beat interval data), our own tool was developed that is available free of charge. To date, more than 100 researchers worldwide have requested the tool. Recently, a new version was developed and released together with a website (www.artiifact.de). (2) Furthermore, a study of this thesis demonstrated that BCI technology can be incorporated into easy-to-use software, including auto-calibration and predictive text entry. Naïve, healthy nonprofessionals were able to control the software without expert support and successfully spelled words using the auto-calibrated BCI. They reported that software handling was straightforward and that they would be able to explain the system to others. However, future research is required to study transfer of the results to patient samples. (3) The commonly used ERP-BCI paradigm was significantly improved. Instead of simply highlighting visually displayed characters as is usually done, pictures of famous faces were used as stimulus material. As a result, specific brain potentials involved in face recognition and face processing were elicited. The event-related EEG thus displayed an increased signal-to-noise ratio, which facilitated the detection of ERPs extremely well. Consequently, BCI performance was significantly increased. (4) The good results of this new face-flashing paradigm achieved with healthy participants transferred well to users with neurodegenerative disease. Using a face paradigm boosted information throughput. Importantly, two users who were highly inefficient with the commonly used paradigm displayed high accuracy when exposed to the face paradigm. The increased signal-to-noise ratio of the recorded EEG thus helped them to overcome their BCI inefficiency. Significance: The presented work at hand (1) successfully identified a physiological predictor of ERP-BCI performance, (2) proved the technology ready to be operated by naïve nonprofessionals without expert support, (3) significantly improved the commonly used spelling paradigm and (4) thereby displayed a way to effectively prevent BCI inefficiency in patients with neurodegenerative disease. Additionally, missing software solutions for appropriate handling of artifacts in heartbeat data encouraged development of our own software tool that is available to the research community free of charge. In sum, this thesis significantly improved current BCI technology and enhanced our understanding of physiological correlates of BCI performance.
Background
Positive associations have been found between quality of life, emotion regulation strategies, and heart rate variability (HRV) in people without intellectual disabilities. However, emotion regulation and HRV have rarely been investigated in people with intellectual disabilities. Assessment of subjectively reported quality of life and emotion regulation strategies in this population is even more difficult when participants are also visually impaired.
Methods
Subjective and objective quality of life, emotion regulation strategies, and HRV at rest were measured in a sample of people with intellectual disabilities and concomitant impaired vision (N = 35). Heart rate was recorded during a 10 min resting period. For the assessment of quality of life and emotion regulation, custom made tactile versions of questionnaire-based instruments were used that enabled participants to grasp response categories.
Results
The combined use of reappraisal and suppression as emotion regulation strategies was associated with higher HRV and quality of life. HRV was associated with objective quality of life only. Emotion regulation strategies partially mediated the relationship between HRV and quality of life.
Conclusions
Results replicate findings about associations between quality of life, emotion regulation, and HRV and extend them to individuals with intellectual disabilities. Furthermore, this study demonstrated that quality of life and emotion regulation could be assessed in such populations even with concomitant impaired vision with modified tactile versions of established questionnaires. HRV may be used as a physiological index to evaluate physical and affective conditions in this population.
We examined whether movement costs as defined by movement magnitude have an impact on distance perception in near space. In Experiment 1, participants were given a numerical cue regarding the amplitude of a hand movement to be carried out. Before the movement execution, the length of a visual distance had to be judged. These visual distances were judged to be larger, the larger the amplitude of the concurrently prepared hand movement was. In Experiment 2, in which numerical cues were merely memorized without concurrent movement planning, this general increase of distance with cue size was not observed. The results of these experiments indicate that visual perception of near space is specifically affected by the costs of planned hand movements.
In 1999, a tragic catastrophe occurred in the Mont Blanc Tunnel, one of the most important transalpine road tunnels. Twenty-seven of the victims never left their vehicles as a result of which they were trapped in smoke and suffocated (Beard & Carvel, 2005). Immediate evacuation is crucial in tunnel fires, but still many tunnel users stay passive. During emergency situations people strongly influence each other’s behavior (e.g. Nilsson & Johansson, 2009a). So far, only few empirical experimental studies investigated the interaction of individuals during emergencies. Recent developments of advanced immersive virtual worlds, allow simulating emergency situations which makes analogue studies possible. In the present dissertation project, theoretical aspects of human behavior and SI in emergencies are addressed (Chapter 1). The question of Social Influence in emergency situations is investigated in five simulation studies during different relevant stages of the evacuation process from a simulated road tunnel fire (Chapter 2). In the last part, the results are discussed and criticized (Chapter 3). Using a virtual reality (VR) road tunnel scenario, study 1 (pilot study) and 2 investigated the effect of information about adequate behavior in tunnel emergencies as well as Social Influence (SI) on drivers’ behavior. Based on a classic study of Darley and Latané (1968) on bystander inhibition, the effect of passive bystanders on self-evacuation was analyzed. Sixty participants were confronted with an accident and smoke in a road tunnel. The presence of bystanders and information status was manipulated and consequently, participants were randomly assigned into four different groups. Informed participants read a brochure containing relevant information about safety behavior in emergency situations prior to the tunnel drives. In the bystander conditions, passive bystanders were situated in a car in front of the emergency situation. Participants who had received relevant information left the car more frequently than the other participants. Neither significant effect of bystanders nor interaction with information status on the participants’ behavior was observed. Study 3 (pilot study) examined a possible alternative explanation for weak SI in VR. Based on the Threshold Theory of Social Influence (Blascovich, 2002b) and the work of Guadagno et al. (2007), the perception of virtual humans as an avatar (a virtual representation of a real human being) or as an agent (a computer-controlled animated character) was manipulated. Subsequently, 32 participants experienced an accident similar to the one in study 1. However, they were co-drivers and a virtual agent (VA) was the driver. Participants reacted differently in avatar and agent condition. Consequently, the manipulation of the avatar condition was implemented in study 4. In study 4, SI within the vehicle was investigated, as drivers are mostly not alone in their car. In a tunnel scenario similar to the first study, 34 participants were confronted with an emergency situation either as drivers or co-drivers. In the driver group, participants drove themselves and a VA was sitting on the passenger seat. Correspondently, participants in the co-driver group were seated on the passenger seat and the VA drove the vehicle on a pre-recorded path. Like in study 1, the tunnel was blocked by an accident and smoke was coming from the accident in one drive. The VA initially stayed inactive after stopping the vehicle but started to evacuate after ca. 30 seconds. About one third of the sample left the vehicle during the situation. There were no significant differences between drivers and co-drivers regarding the frequency of leaving the vehicle. Co-drivers waited significantly longer than drivers before leaving the vehicle. Study 5 looked at the pre-movement and movement phase of the evacuation process. Forty participants were repeatedly confronted with an emergency situation in a virtual road tunnel filled with smoke. Four different experimental conditions systematically varied the presence and behavior of a VA. In all but one conditions a VA was present. Across all conditions at least 60% of the participants went to the emergency exit. If the VA went to the emergency exit, the ratio increased to 75%. If the VA went in the opposite direction of the exit, however, only 61% went there. If participants were confronted with a passive VA, they needed significantly longer until they started moving and reached the emergency exit. The main and most important finding across all studies is that SI is relevant for self-evacuation, but the degree of SI varies across the phases of evacuation and situation. In addition to the core findings, relevant theoretical and methodological questions regarding the general usefulness and limitations of VR as a research tool are discussed. Finally, a short summary and outlook on possible future studies is presented.
The aim of the present piece of work was to give information about the frequency of psychoactive substances within the German driver population and to identify preventive and promotive circumstances of drug driving. Furthermore, a new methodological approach to gather and link data about the consumption of psychoactive substances and the mobility of drug users is shown. Traditionally, roadside surveys are conducted to estimate the prevalence of drug driving within a population. By the present study, an alternative method is introduced. In total, 195 drug users (mainly cannabis users) and 100 controls out of the normal driving population were queried for four weeks about their driving and drug consumption behaviour by a questionnaire that was deployed on smartphones. The prevalences of drug driving within the sample were extrapolated into representative values. Because the subjects reported all daily activities within the study-period, it was also possible to describe situations in which the subjects decided against driving under influence. Besides, relevant previous experiences, attitudes, the approval of legal regulations, other traffic-specific parameters, social influences and personality variables were queried. So, individual factors that are associated with drug driving can be specified. The results are integrated in a model that shows dependencies of different societal, behavioural and legal variables. They can serve as major input to the discussion on drug driving and can be of practical use for rehabilitation and prevention purposes. The results can be summarised as follows: - Compared to the results of a German roadside survey from 1994, the prevalences that are found within the present study seem pretty low. This finding is discussed and possible explanations for the described trend are lined out. Furthermore, the prevalences that were calculated in the present study are compared to current data from other European countries. - The results show differences between users and controls on several variables. The differences indicate that substance use impacts on the structuring of day-to-day life. Overall, the controls’ days proceed more along a daily working routine than the users’ (e.g. less mobility at night, more mobility at rush-hour, alcohol consumption mainly at nights out). - The individual extent to which drugs are consumed differs dependent on daytime, day of the week and kind of substance. Of course, these dependencies also influence the occurrence of drug driving. Other factors of influence on drug driving are the distance, the availability of alternative modes of transport as well as the presence of female companions. - Not everybody who uses drugs drives under the influence of drugs. A striking predictor for frequent drug driving and highly intoxicated driving is a high consumption, associated with risky consumption patterns and a low subjective feeling of impairment after drug consumption. - The subjects’ attitudes towards drug driving and their beliefs about social norms largely go in line with the behaviour they engage in. Drug users have rather liberal attitudes towards drug use and driving under influence. - A possible deterrence effect of sanctioning and police enforcement and its dependence on the acceptance and awareness of the measures is delineated. - Only small effects are found when examining the objective impairment that is caused by drug use by a computer-based test battery. This result is critically discussed with regards to the operationalisation of the study groups. - Except from driving under influence, there is no evidence to suggest that DUI offenders also show problematic behaviour according to other traffic-related measures. - Parents and peers may have an influence as role models on the development of problematic behaviour. A good relationship between parents and children may have a positive impact on the development of conventional values and behaviour. - Drug use is associated with some crucial personality dimensions and drugs are often used to solve personal problems. A less precise but similar difference was found for users who commit many drives under influence compared to users who never or only sometimes drive under influence. Moreover, users marginally more often have psychological problems compared to controls. Finally, the strengths and weaknesses of the new methodological approach of data collection are discussed as well as the challenges that are faced when implementing it. All in all, it has proved to be a promising method and should serve as a standard to which future studies should aspire.
RATIONALE:
The endocannabinoid (eCB) system is implicated in several psychiatric disorders. Investigating emotional-motivational dysfunctions as underlying mechanisms, a study in humans revealed that in the C385A polymorphism of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the eCB anandamide (AEA), A carriers, who are characterized by increased signaling of AEA as compared to C/C carriers, exhibited reduced brain reactivity towards unpleasant faces and enhanced reactivity towards reward. However, the association of eCB system with emotional-motivational reactivity is complex and bidirectional due to upcoming compensatory processes.
OBJECTIVES:
Therefore, we further investigated the relationship of the FAAH polymorphism and emotional-motivational reactivity in humans.
METHODS:
We assessed the affect-modulated startle, and ratings of valence and arousal in response to higher arousing pleasant, neutral, and unpleasant pictures in 67 FAAH C385A C/C carriers and 45 A carriers.
RESULTS:
Contrarily to the previous functional MRI study, A carriers compared to C/C carriers exhibited an increased startle potentiation and therefore emotional responsiveness towards unpleasant picture stimuli and reduced startle inhibition indicating reduced emotional reactivity in response to pleasant pictures, while both groups did not differ in ratings of arousal and valence.
CONCLUSIONS:
Our findings emphasize the bidirectionality and thorough examination of the eCB system's impact on emotional reactivity as a central endophenotype underlying various psychiatric disorders.
Anticipating where an event will occur enables us to instantaneously respond to events that occur at the expected location. Here we investigated if such spatial anticipations can be triggered by symbolic information that participants cannot consciously see. In two experiments involving a Posner cueing task and a visual search task, a central cue informed participants about the likely location of the next target stimulus. In half of the trials, this cue was rendered invisible by pattern masking. In both experiments, visible cues led to cueing effects, that is, faster responses after valid compared to invalid cues. Importantly, even masked cues caused cueing effects, though to a lesser extent. Additionally, we analyzed effects on attention that persist from one trial to the subsequent trial. We found that spatial anticipations are able to interfere with newly formed spatial anticipations and influence orienting of attention in the subsequent trial. When the preceding cue was visible, the corresponding spatial anticipation persisted to an extent that prevented a noticeable effect of masked cues. The effects of visible cues were likewise modulated by previous spatial anticipations, but were strong enough to also exert an impact on attention themselves. Altogether, the results suggest that spatial anticipations can be formed on the basis of unconscious stimuli, but that interfering influences like still active spatial anticipations can suppress this effect.
Rumination has been defined as a mode of responding to distress that involves passively focusing one's attention on symptoms of distress without taking action. This dysfunctional response style intensifies depressed mood, impairs interpersonal problem solving, and leads to more pessimistic future perspectives and less social support. As most of these results were obtained from younger people, it remains unclear how age affects ruminative thinking. Three hundred members of the general public ranging in age from 15 to 87 years were asked about their ruminative styles using the Response Styles Questionnaire (RSQ), depression and satisfaction with life. A Mokken Scale analysis confirmed the two-factor structure of the RSQ with brooding and reflective pondering as subcomponents of rumination. Older participants (63 years and older) reported less ruminative thinking than other age groups. Life satisfaction was associated with brooding and highest for the earlier and latest life stages investigated in this study.
An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers experience difficulties in translating their attitudes into an actual behavior change.
Respiratory sinus arrhythmia (RSA) is related to cardiac vagal outflow and the respiratory pattern. Prior infant studies have not systematically examined respiration rate and tidal volume influences on infant RSA or the extent to which infants' breathing is too fast to extract a valid RSA. We therefore monitored cardiac activity, respiration, and physical activity in 23 six-month old infants during a standardized laboratory stressor protocol. On average, 12.6% (range 0-58.2%) of analyzed breaths were too short for RSA extraction. Higher respiration rate was associated with lower RSA amplitude in most infants, and lower tidal volume was associated with lower RSA amplitude in some infants. RSA amplitude corrected for respiration rate and tidal volume influences showed theoretically expected strong reductions during stress, whereas performance of uncorrected RSA was less consistent. We conclude that stress-induced changes of peak-valley RSA and effects of variations in breathing patterns on RSA can be determined for a representative percentage of infant breaths. As expected, breathing substantially affects infant RSA and needs to be considered in studies of infant psychophysiology.
Background: One of the most common types of brain-computer interfaces (BCIs) is called a P300 BCI, since it relies on the P300 and other event-related potentials (ERPs). In the canonical P300 BCI approach, items on a monitor flash briefly to elicit the necessary ERPs. Very recent work has shown that this approach may yield lower performance than alternate paradigms in which the items do not flash but instead change in other ways, such as moving, changing colour or changing to characters overlaid with faces.
Methodology/Principal Findings: The present study sought to extend this research direction by parametrically comparing different ways to change items in a P300 BCI. Healthy subjects used a P300 BCI across six different conditions. Three conditions were similar to our prior work, providing the first direct comparison of characters flashing, moving, and changing to faces. Three new conditions also explored facial motion and emotional expression. The six conditions were compared across objective measures such as classification accuracy and bit rate as well as subjective measures such as perceived difficulty. In line with recent studies, our results indicated that the character flash condition resulted in the lowest accuracy and bit rate. All four face conditions (mean accuracy >91%) yielded significantly better performance than the flash condition (mean accuracy = 75%).
Conclusions/Significance: Objective results reaffirmed that the face paradigm is superior to the canonical flash approach that has dominated P300 BCIs for over 20 years. The subjective reports indicated that the conditions that yielded better performance were not considered especially burdensome. Therefore, although further work is needed to identify which face paradigm is best, it is clear that the canonical flash approach should be replaced with a face paradigm when aiming at increasing bit rate. However, the face paradigm has to be further explored with practical applications particularly with locked-in patients.
The individual sensitivity for ones internal bodily signals ("interoceptive awareness") has been shown to be of relevance for a broad range of cognitive and affective functions. Interoceptive awareness has been primarily assessed via measuring the sensitivity for ones cardiac signals ("cardiac awareness") which can be non-invasively measured by heartbeat perception tasks. It is an open question whether cardiac awareness is related to the sensitivity for other bodily, visceral functions. This study investigated the relationship between cardiac awareness and the sensitivity for gastric functions in healthy female persons by using non-invasive methods. Heartbeat perception as a measure for cardiac awareness was assessed by a heartbeat tracking task and gastric sensitivity was assessed by a water load test. Gastric myoelectrical activity was measured by electrogastrography (EGG) and subjective feelings of fullness, valence, arousal and nausea were assessed. The results show that cardiac awareness was inversely correlated with ingested water volume and with normogastric activity after water load. However, persons with good and poor cardiac awareness did not differ in their subjective ratings of fullness, nausea and affective feelings after drinking. This suggests that good heartbeat perceivers ingested less water because they subjectively felt more intense signals of fullness during this lower amount of water intake compared to poor heartbeat perceivers who ingested more water until feeling the same signs of fullness. These findings demonstrate that cardiac awareness is related to greater sensitivity for gastric functions, suggesting that there is a general sensitivity for interoceptive processes across the gastric and cardiac modality.
The etiology of emotion-related disorders such as anxiety or affective disorders is considered to be complex with an interaction of biological and environmental factors. Particular evidence has accumulated for alterations in the dopaminergic and noradrenergic system - partly conferred by catechol-O-methyltransferase (COMT) gene variation - for the adenosinergic system as well as for early life trauma to constitute risk factors for those conditions. Applying a multi-level approach, in a sample of 95 healthy adults, we investigated effects of the functional COMT Val158Met polymorphism, caffeine as an adenosine A2A receptor antagonist (300 mg in a placebo-controlled intervention design) and childhood maltreatment (CTQ) as well as their interaction on the affect-modulated startle response as a neurobiologically founded defensive reflex potentially related to fear- and distress-related disorders. COMT val/val genotype significantly increased startle magnitude in response to unpleasant stimuli, while met/met homozygotes showed a blunted startle response to aversive pictures. Furthermore, significant gene-environment interaction of COMT Val158Met genotype with CTQ was discerned with more maltreatment being associated with higher startle potentiation in val/val subjects but not in met carriers. No main effect of or interaction effects with caffeine were observed. Results indicate a main as well as a GxE effect of the COMT Val158Met variant and childhood maltreatment on the affect-modulated startle reflex, supporting a complex pathogenetic model of the affect-modulated startle reflex as a basic neurobiological defensive reflex potentially related to anxiety and affective disorders.
Face processing can be explored using electrophysiological methods. Research with event-related potentials has demonstrated the so-called face inversion effect, in which the N170 component is enhanced in amplitude and latency to inverted, compared to upright, faces. The present study explored the extent to which repetitive lower-level visual cortical engagement, reflected in flicker steady-state visual evoked potentials (ssVEPs), shows similar amplitude enhancement to face inversion. We also asked if inversion-related ssVEP modulation would be dependent on the stimulation rate at which upright and inverted faces were flickered. To this end, multiple tagging frequencies were used (5, 10, 15, and 20 Hz) across two studies (n=21, n=18). Results showed that amplitude enhancement of the ssVEP for inverted faces was found solely at higher stimulation frequencies (15 and 20 Hz). By contrast, lower frequency ssVEPs did not show this inversion effect. These findings suggest that stimulation frequency affects the sensitivity of ssVEPs to face inversion.
This paper seeks to unify two major theories of moral judgment: Kohlberg's stage theory and Anderson's moral information integration theory. Subjects were told about thoughts of actors in Kohlberg's classic altruistic Heinz dilemma and in a new egoistical dilemma. These actors's thoughts represented Kohlberg's stages I (Personal Risk) and IV (Societal Risk) and had three levels, High, Medium, and Low. They were presented singly and in a 3 x 3 integration design. Subjects judged how many months of prison the actor deserved. The data supported the averaging model of moral integration theory, whereas Kohlberg's theory has no way to handle the integration problem. Following this, subjects ranked statements related to Kohlberg's first four stages in a procedure similar to that of Rest (1975). Higher score went with larger effect of Societal Risk as predicted by Kohlberg's theory. But contrary to Kohlberg's theory, no age trends were found. Also strongly contrary to Kohlberg's theory, effects of Personal Risk (Stage I) and Societal Risk (Stage IV) correlated positively.
Previous research using neuroimaging methods proposed a link between mechanisms controlling motor response inhibition and suppression of unwanted memories.The present study investigated this hypothesis behaviorally by combining the think/no-think paradigm (TNT) with a go/no-go motor inhibition task. Participants first learned unpleasant cue-target pairs. Cue words were then presented as go or no-go items in the TNT. Participants’ task was to respond to the cues and think of the target word aloud or to inhibit their response to the cue and the target word from coming to mind. Cued recall assessed immediately after the TNT revealed reduced recall performance for no-go targets compared to go targets or baseline cues not presented in the TNT. The results demonstrate that doing the no-think and no-go task concurrently leads to memory suppression of unpleasant items during later recall. Results are discussed in line with recent empirical research and theoretical positions.
Flexible behavior is only possible if contingencies between own actions and following environmental effects are acquired as quickly as possible; and recent findings indeed point toward an immediate formation of action-effect bindings already after a single coupling of an action and its effect. The present study explored whether these short-term bindings occur for both, stimulus- and goal-driven actions (“forced-choice actions” vs. “free-choice actions”). Two experiments confirmed that immediate action-effect bindings are formed for both types of actions and affect upcoming behavior. These findings support the view that action-effect binding is a ubiquitous phenomenon which occurs for any type of action.
When a key press causes a stimulus, the key press is perceived later and the stimulus earlier than key presses and stimuli presented independently. This bias in time perception has been linked to the intention to produce the effect and thus been called intentional binding (IB). In recent studies it has been shown that the IB effect is stronger when participants believed that they caused the effect stimulus compared to when they believed that another person caused the effect (Desantis et al., 2011). In this experiment we ask whether causal beliefs influence the perceived time of an effect when the putative effect occurs temporally close to another stimulus that is also an effect. In our study two participants performed the same task on connected computers with separate screens. Each trial started synchro- nously on both computers. When a participant pressed a key, a red and a yellow stimulus appeared as action effects simultaneously or with a slight delay of up to 50 ms. The partic- ipants’ task was to judge the temporal order of these two effect stimuli. Participants were either told that one participant caused one of the two stimuli while the other participant seated at the other computer caused the other stimulus, or each participant was told that he/she caused both stimuli. The different causal beliefs changed the perceived time of the effects’ appearance relative to each other. When participants believed they each caused one effect, their “own” effect was perceived earlier than the other participant’s effect. When the participants believed each caused both effects, no difference in the perceived temporal order of the red and yellow effect was found. These results confirm that higher order causal beliefs change the perceived time of an action effect even in a setting in which the occurrence of the putative effect can be directly compared to a reference stimulus.
Background: A solid diagnosis of sleep disorders in children should include both self-ratings and parent ratings. However, there are few standardized self-assessment instruments to meet this need. The Children’s Sleep Comic is an adapted version of the unpublished German questionnaire “Freiburger Kinderschlafcomic” and provides pictures for items and responses. Because the drawings were outdated and allowed only for qualitative analysis, we revised the comic, tested its applicability in a target sample, and suggest a procedure for quantitative analysis. Methods: All items were updated and pictures were newly drawn. We used a sample of 201 children aged 5–10 years to test the applicability of the Children’s Sleep Comic in young children and to run a preliminary analysis. Results: The Children’s Sleep Comic comprises 37 items covering relevant aspects of sleep disorders in children. Application took on average 30 minutes. The procedure was well accepted by the children, as reflected by the absence of any dropouts. First comparisons with established questionnaires indicated moderate correlations. Conclusion: The Children’s Sleep Comic is appropriate for screening sleep behavior and sleep problems in children. The interactive procedure can foster a good relationship between the investigator and the child, and thus establish the basis for successful intervention if necessary.
Brain–computer interfaces (BCI) based on event-related potentials (ERP) allow for selection of characters from a visually presented character-matrix and thus provide a communica- tion channel for users with neurodegenerative disease. Although they have been topic of research for more than 20 years and were multiply proven to be a reliable communication method, BCIs are almost exclusively used in experimental settings, handled by qualified experts. This study investigates if ERP–BCIs can be handled independently by laymen without expert support, which is inevitable for establishing BCIs in end-user’s daily life situations. Furthermore we compared the classic character-by-character text entry against a predictive text entry (PTE) that directly incorporates predictive text into the character- matrix. N = 19 BCI novices handled a user-centered ERP–BCI application on their own without expert support. The software individually adjusted classifier weights and control parameters in the background, invisible to the user (auto-calibration). All participants were able to operate the software on their own and to twice correctly spell a sentence with the auto-calibrated classifier (once with PTE, once without). Our PTE increased spelling speed and, importantly, did not reduce accuracy. In sum, this study demonstrates feasi- bility of auto-calibrating ERP–BCI use, independently by laymen and the strong benefit of integrating predictive text directly into the character-matrix.
Faces in context: A review and systematization of contextual influences on affective face processing
(2012)
Facial expressions are of eminent importance for social interaction as they convey information about other individuals’ emotions and social intentions. According to the predominant “basic emotion” approach, the perception of emotion in faces is based on the rapid, auto- matic categorization of prototypical, universal expressions. Consequently, the perception of facial expressions has typically been investigated using isolated, de-contextualized, static pictures of facial expressions that maximize the distinction between categories. However, in everyday life, an individual’s face is not perceived in isolation, but almost always appears within a situational context, which may arise from other people, the physical environment surrounding the face, as well as multichannel information from the sender. Furthermore, situational context may be provided by the perceiver, including already present social infor- mation gained from affective learning and implicit processing biases such as race bias.Thus, the perception of facial expressions is presumably always influenced by contextual vari- ables. In this comprehensive review, we aim at (1) systematizing the contextual variables that may influence the perception of facial expressions and (2) summarizing experimental paradigms and findings that have been used to investigate these influences. The studies reviewed here demonstrate that perception and neural processing of facial expressions are substantially modified by contextual information, including verbal, visual, and auditory information presented together with the face as well as knowledge or processing biases already present in the observer. These findings further challenge the assumption of auto- matic, hardwired categorical emotion extraction mechanisms predicted by basic emotion theories. Taking into account a recent model on face processing, we discuss where and when these different contextual influences may take place, thus outlining potential avenues in future research.
Numerous studies have shown that humans automatically react with congruent facial reactions, i.e., facial mimicry, when seeing a vis-á-vis’ facial expressions. The current experiment is the first investigating the neuronal structures responsible for differences in the occurrence of such facial mimicry reactions by simultaneously measuring BOLD and facial EMG in an MRI scanner. Therefore, 20 female students viewed emotional facial expressions (happy, sad, and angry) of male and female avatar characters. During picture presentation, the BOLD signal as well as M. zygomaticus major and M. corrugator supercilii activity were recorded simultaneously. Results show prototypical patterns of facial mimicry after correction for MR-related artifacts: enhanced M. zygomaticus major activity in response to happy and enhanced M. corrugator supercilii activity in response to sad and angry expressions. Regression analyses show that these congruent facial reactions correlate significantly with activations in the IFG, SMA, and cerebellum. Stronger zygomaticus reactions to happy faces were further associated to increased activities in the caudate, MTG, and PCC. Corrugator reactions to angry expressions were further correlated with the hippocampus, insula, and STS. Results are discussed in relation to core and extended models of the mirror neuron system (MNS).
In recent years, Ideomotor Theory has regained widespread attention and sparked the development of a number of theories on goal-directed behavior and learning. However, there are two issues with previous studies’ use of Ideomotor Theory. Although Ideomotor Theory is seen as very general, it is often studied in settings that are considerably more simplistic than most natural situations. Moreover, Ideomotor Theory’s claim that effect anticipations directly trigger actions and that action-effect learning is based on the formation of direct action-effect associations is hard to address empirically. We address these points from a computational perspective. A simple computational model of Ideomotor Theory was tested in tasks with different degrees of complexity.The model evaluation showed that Ideomotor Theory is a computationally feasible approach for understanding efficient action-effect learning for goal-directed behavior if the following preconditions are met: (1) The range of potential actions and effects has to be restricted. (2) Effects have to follow actions within a short time window. (3) Actions have to be simple and may not require sequencing. The first two preconditions also limit human performance and thus support Ideomotor Theory. The last precondition can be circumvented by extending the model with more complex, indirect action generation processes. In conclusion, we suggest that IdeomotorTheory offers a comprehensive framework to understand action-effect learning. However, we also suggest that additional processes may mediate the conversion of effect anticipations into actions in many situations.
Both specific stimulus valence and unspecific processing dynamics can influence evaluative responses. Eight experiments investigated their respective influence on evaluative judgments in the domain of stereotyping. Valence of stereotypic information and consistency-driven fluency were manipulated in an impression formation paradigm. When information about the to-be-evaluated target person was strongly valenced, no effects of consistency-driven fluency were observed. Higher cognitive processes, valence of inconsistent attributes, processing priority of category information, and impression formation instructions were ruled out as possible factors responsible for the non-occurrence of fluency effects. However, consistency-driven fluency did influence the evaluative judgment, if the information about a target person was not strongly valenced. It is therefore concluded that both stimulus valence and consistency-driven processing fluency play a role in evaluative judgments in the domain of stereotyping. The respective impact of stimulus valence is much stronger than the impact of unspecific processing dynamics, however. Implications for fluency research and the applied field of stereotype change are discussed.
A brain-computer interface (BCI) enables communication without movement based on brain signals measured with electroencephalography (EEG). BCIs usually rely on one of three types of signals: the P300 and other components of the event-related potential (ERP), steady state visual evoked potential (SSVEP), or event related desynchronization (ERD). Although P300 BCIs were introduced over twenty years ago, the past few years have seen a strong increase in P300 BCI research. This closed-loop BCI approach relies on the P300 and other components of the ERP, based on an oddball paradigm presented to the subject. In this paper, we overview the current status of P300 BCI technology, and then discuss new directions: paradigms for eliciting P300s; signal processing methods; applications; and hybrid BCIs. We conclude that P300 BCIs are quite promising, as several emerging directions have not yet been fully explored and could lead to improvements in bit rate, reliability, usability, and flexibility.
Introduction: Sleep disturbances are common in adolescents and adversely affect performance, social contact, and susceptibility to stress. We investigated the hypothesis of a relationship between sleep and health-related quality of life (HRQoL), and applied self- and proxy ratings. Materials and Methods: The sample comprised 92 adolescents aged 11–17 years. All participants and their parents completed a HRQoL measure and the Sleep Disturbance Scale for Children (SDSC ). Children with SDSC T -scores above the normal range (above 60) were classified as poor sleepers. Results: According to self- and proxy ratings, good sleepers reported significantly higher HRQoL than poor sleep- ers. Sleep disturbances were significantly higher and HRQoL significantly lower in self- as compared to parental ratings. Parent-child agreement was higher for subscales measuring observable aspects. Girls experienced significantly stronger sleep disturbances and lower self-rated HRQoL than boys. Discussion: Our findings support the positive relationship of sleep and HRQoL. Furthermore, parents significantly underestimate sleep disturbances and overestimate HRQoL in their children.
The limbic system and especially the amygdala have been identified as key structures in emotion induction and regulation. Recently research has additionally focused on the influence of prefrontal areas on emotion processing in the limbic system and the amygdala. Results from fMRI studies indicate that the prefrontal cortex (PFC) is involved not only in emotion induction but also in emotion regulation. However, studies using fNIRS only report prefrontal brain activation during emotion induction. So far it lacks the attempt to compare emotion induction and emotion regulation with regard to prefrontal activation measured with fNIRS, to exclude the possibility that the reported prefrontal brain activation in fNIRS studies are mainly caused by automatic emotion regulation processes. Therefore this work tried to distinguish emotion induction from regulation via fNIRS of the prefrontal cortex. 20 healthy women viewed neutral pictures as a baseline condition, fearful pictures as induction condition and reappraised fearful pictures as regulation condition in randomized order. As predicted, the view-fearful condition led to higher arousal ratings than the view-neutral condition with the reappraise-fearful condition in between. For the fNIRS results the induction condition showed an activation of the bilateral PFC compared to the baseline condition (viewing neutral). The regulation condition showed an activation only of the left PFC compared to the baseline condition, although the direct comparison between induction and regulation condition revealed no significant difference in brain activation. Therefore our study underscores the results of previous fNIRS studies showing prefrontal brain activation during emotion induction and rejects the hypothesis that this prefrontal brain activation might only be a result of automatic emotion regulation processes.
Arrow cues and other overlearned spatial symbols automatically orient attention according to their spatial meaning. This renders them similar to exogenous cues that occur at stimulus location. Exogenous cues trigger shifts of attention even when they are presented subliminally. Here, we investigate to what extent the mechanisms underlying the orienting of attention by exogenous cues and by arrow cues are comparable by analyzing the effects of visible and masked arrow cues on attention. In Experiment 1, we presented arrow cues with overall 50% validity. Visible cues, but not masked cues, lead to shifts of attention. In Experiment 2, the arrow cues had an overall validity of 80%. Now both visible and masked arrows lead to shifts of attention. This is in line with findings that subliminal exogenous cues capture attention only in a top-down contingent manner, that is, when the cues fit the observer’s intentions.
Our object recognition abilities, a direct product of our experience with objects, are fine-tuned to perfection. Left temporal and lateral areas along the dorsal, action related stream, as well as left infero-temporal areas along the ventral, object related stream are engaged in object recognition. Here we show that expertise modulates the activity of dorsal areas in the recognition of man-made objects with clearly specified functions. Expert chess players were faster than chess novices in identifying chess objects and their functional relations. Experts’ advantage was domain-specific as there were no differences between groups in a control task featuring geometrical shapes. The pattern of eye movements supported the notion that experts’ extensive knowledge about domain objects and their functions enabled superior recognition even when experts were not directly fixating the objects of interest. Functional magnetic resonance imaging (fMRI) related exclusively the areas along the dorsal stream to chess specific object recognition. Besides the commonly involved left temporal and parietal lateral brain areas, we found that only in experts homologous areas on the right hemisphere were also engaged in chess specific object recognition. Based on these results, we discuss whether skilled object recognition does not only involve a more efficient version of the processes found in non-skilled recognition, but also qualitatively different cognitive processes which engage additional brain areas
The wardrobe malfunction—an unanticipated exposure of bodily parts in the public—has become a prevailing issue in concerts, shows and other celebrity events that is reliably reported by the media. The internet as the fastest source for celebrity gossip allows measuring the impact of such wardrobe malfunctions on the public in-terest in a celebrity. This measurement in turn allows conclusions about intention, motivation, and internet be-haviour of a wide variety of internet users. The present study exemplifies the use of an innovative non-reactive measure of active interest—the Search Volume Index—to assess the impact of a variety of internet-related phe-nomena, including wardrobe malfunctions. Results indicate that interest in a celebrity increases immediately af-ter such an event and stays at a high level for about three weeks (the wardrobe plateau). This special form of ce-lebrity gossip thus meets a constant interest of a substantial proportion of internet users.
It has been proposed that different features of a face provide a source of information for separate perceptual and cognitive processes. Properties of a face that remain rather stable over time, so called invariant facial features, yield information about a face’s identity, and changeable aspects of faces transmit information underlying social communication such as emotional expressions and speech movements. While processing of these different face properties was initially claimed to be independent, a growing body of evidence suggests that these sources of information can interact when people recognize faces with whom they are familiar. This is the case because the way a face moves can contain patterns that are characteristic for that specific person, so called idiosyncratic movements. As a face becomes familiar these idiosyncratic movements are learned and hence also provide information serving face identification. While an abundance of experiments has addressed the independence of invariant and variable facial features in face recognition, little is known about the exact nature of the impact idiosyncratic facial movements have on face recognition. Gaining knowledge about the way facial motion contributes to face recognition is, however, important for a deeper understanding of the way the brain processes and recognizes faces. In the following dissertation three experiments are reported that investigate the impact familiarity of changeable facial features has on processes of face recognition. Temporal aspects of the processing of familiar idiosyncratic facial motion were addressed in the first experiment via EEG by investigating the influence familiar facial movement exerts on event-related potentials associated to face processing and face recognition. After being familiarized with a face and its idiosyncratic movement, participants viewed familiar or unfamiliar faces with familiar or unfamiliar facial movement while their brain potentials were recorded. Results showed that familiarity of facial motion influenced later event-related potentials linked to memory processes involved in face recognition. The second experiment used fMRI to investigate the brain areas involved in processing familiar facial movement. Participants’ BOLD-signal was registered while they viewed familiar and unfamiliar faces with familiar or unfamiliar idiosyncratic movement. It was found that activity of brain regions, such as the fusiform gyrus, that underlie the processing of face identity, was modulated by familiar facial movement. Together these two experiments provide valuable information about the nature of the involvement of idiosyncratic facial movement in face recognition and have important implications for cognitive and neural models of face perception and recognition. The third experiment addressed the question whether idiosyncratic facial movement could increase individuation in perceiving faces from a different ethnic group and hence reduce impaired recognition of these other-race faces compared to own-race faces, a phenomenon named the own-race bias. European participants viewed European and African faces that were each animated with an idiosyncratic smile while their attention was either directed to the form or the motion of the face. Subsequently recognition memory for these faces was tested. Results showed that the own-race bias was equally present in both attention conditions indicating that idiosyncratic facial movement was not able to reduce or diminish the own-race bias. In combination the here presented experiments provide further insight into the involvement of idiosyncratic facial motion in face recognition. It is necessary to consider the dynamic component of faces when investigating face recognition because static facial images are not able to provide the full range of information that leads to recognition of a face. In order to reflect the full process of face recognition, cognitive and neural models of face perception and recognition need to integrate dynamic facial features as a source of information which contributes to the recognition of a face.
Just do it! Guilt as a moral intuition to cooperate - A parallel constraint satisfaction approach
(2011)
After a long dominance of rational models of judgment and decision-making in moral psychology (e.g. Kohlberg, 1969) there is now a strong interest in how intuitions and emotions influence moral judgments and decisions (e.g. Greene, 2007; Haidt, 2001; Monin, Pizarro, & Beer, 2007). In the literature, the influence of emotions on moral decisions is explained by heuristic or non-compensatory information processing (e.g. Sinnott-Armstrong, Young, & Cushman, 2010; Sunstein, 2005; Tobler, Kalis, & Kalenscher, 2008). However, the process of emotion elicitation is ignored. Appraisal theories postulate that emotion elicitation is due to the incoherence (or discrepancy) of behavioral representations like goals and actions (Moors, 2009). Emotion elicitation and intuitive decision-making can be combined if both processes apply a connectionist information processing structure (e.g. Barnes & Thagard, 1996). The current work contrasts both perspectives of intuitive-emotional decision-making with respect to guilt and cooperation.
The present study investigated event-related brain potentials elicited by true and false negated statements to evaluate if discrimination of the truth value of negated information relies on conscious processing and requires higher-order cognitive processing in healthy subjects across different levels of stimulus complexity. The stimulus material consisted of true and false negated sentences (sentence level) and prime-target expressions (word level). Stimuli were presented acoustically and no overt behavioral response of the participants was required. Event-related brain potentials to target words preceded by true and false negated expressions were analyzed both within group and at the single subject level. Across the different processing conditions (word pairs and sentences), target words elicited a frontal negativity and a late positivity in the time window from 600–1000 msec post target word onset. Amplitudes of both brain potentials varied as a function of the truth value of the negated expressions. Results were confirmed at the single-subject level. In sum, our results support recent suggestions according to which evaluation of the truth value of a negated expression is a time- and cognitively demanding process that cannot be solved automatically, and thus requires conscious processing. Our paradigm provides insight into higher-order processing related to language comprehension and reasoning in healthy subjects. Future studies are needed to evaluate if our paradigm also proves sensitive for the detection of consciousness in non-responsive patients.
Humans have the tendency to react with congruent facial expressions when looking at an emotional face. Interestingly, recent studies revealed that several situational moderators can modulate strength and direction of these reactions. In current literature, congruent facial reactions to emotional facial expressions are usually described in terms of “facial mimicry” and interpreted as imitative behavior. Thereby, facial mimicry is understood as a process of pure motor resonance resulting from overlapping representations for the perception and the execution of a certain behavior. Motor mimicry, however, is not the only mechanism by which congruent facial reactions can occur. Numerous studies have shown that facial muscles also indicate valence evaluations. Furthermore, facial reactions are also determined by our current emotional state. These thoughts suggest that the modulation of congruent facial reactions to emotional expressions can be based on both motor and affective processes. However, a separation of motor and affective processes in facial reactions is hard to make. None of the published studies that tried that could show a clear involvement of one or the other process so far. Therefore, the aim of the present line of experiments is to shed light on the involvement of motor and affective processes in the modulation of congruent and incongruent facial reactions. Specifically, the experiments are designed to test the assumptions of a working model on mechanisms underlying the modulation of facial reactions and to examine the neuronal correlates involved in such modulations with a broad range of methods. Experiments 1 and 2 experimentally manipulate motor and affective mechanisms by using specific contexts. In the chose settings, motor process models and affective models of valence evaluations make competing predictions about resulting facial reactions. The results of Experiment 1 did not support the involvement of valence evaluations in the modulation of congruent and incongruent facial reactions to facial expressions. The results of Experiments 2a and 2b suggest that emotional reactions are the predominant determinant of facial reactions. Experiment 3 aimed at identifying the psychological mediators that indicate motor and affective mechanisms. Motor mechanisms are assessed via the psychological mediator empathy. Additionally, as a psychological mediator for clarifying the role of affective mechanisms subjective measures of the participants’ current emotional state in response to the presented facial expressions were taken. Mediational analyses show that the modulation of congruent facial reactions can be explained by a decrease of state cognitive empathy. This suggests that motor processes mediate the effects of the context on congruent facial reactions. However, such a mechanism could not be observed for incongruent reactions. Instead, it was found that affective processes in terms of emotional reactions are involved in incongruent facial reactions. Additionally, the involvement of a third class of processes, namely strategic processes, was observed. Experiment 4 aimed at investigating whether a change in the strength of perception can explain the contextual modulation of facial reactions to facial expressions. According to motor process models the strength of perception is directly related to the strength of the spread of activation from perception to the execution of an action and thereby to the strength of the resulting mimicry behavior. The results suggest that motor mechanisms were involved in the modulation of congruent facial reactions by attitudes. Such an involvement of motor mechanisms could, however, not be observed for the modulation of incongruent reactions. In Experiment 5 the investigation of neuronal correlates shall be extended to the observation of involved brain areas via fMRI. The proposed brain areas depicting motor areas were prominent parts of the mirror neuron system. The regions of interest depicting areas involved in the affective processing were amygdala, insula, striatum. Furthermore, it could be shown that changes in the activity of parts of the MNS are related to the modulation of congruent facial reactions. Further on, results revealed the involvement of affective processes in the modulation of incongruent facial reactions. In sum, these results lead to a revised working model on the mechanisms underlying the modulation of facial reactions to emotional facial expressions. The results of the five experiments provide strong support for the involvement of motor mechanisms in congruent facial reactions. No evidence was found for the involvement of motor mechanisms in the occurrence or modulation of incongruent facial reactions. Furthermore, no evidence was found for the involvement of valence evaluations in the modulation of facial reactions. Instead, emotional reactions were found to be involved in the modulation of mainly incongruent facial reactions.
The scope of the present work encompasses the influence of experience (i.e. expertise) for feature processing in unconscious information processing. In the introduction, I describe the subliminal priming paradigm, a method to examine how stimuli, we are not aware of, nonetheless influence our actions. The activation of semantic response categories, the impact of learned stimulus-response links, and the action triggering through programmed stimulus-response links are the main three hypotheses to explain unconscious response activation. Besides, the congruence of perceptual features can also influence subliminal priming. On the basis of the features location and form, I look at evidence that exists so far for perceptual priming. The second part of the introduction reviews the literature showing perceptual superiority of experts. This is illustrated exemplarily with three domains of expertise – playing action video games, which constitutes a general form of perceptual expertise, radiology, a more natural form of expertise, and expertise in the game of chess, which is seen as the Drosophila of psychology. In the empirical section, I report nine experiments that applied a subliminal check detection task. Experiment 1 shows subliminal response priming for chess experts but not for chess novices. Thus, chess experts are able to judge unconsciously presented chess configurations as checking or nonchecking. The results of Experiment 2 suggest that acquired perceptual chunks, and not the ability to integrate perceptual features unconsciously, was responsible for unconscious check detection, because experts’ priming does not occur for simpler chess configurations which afforded an unfamiliar classification. With a more complex chess detection task, Experiment 3 indicates that chess experts are not able to process perceptual features in parallel or alternatively, that chess experts are not able to form specific expectations which are obviously necessary to elicit priming if many chess displays are applied. The aim of Experiment 4-9 was to further elaborate on unconscious processing of the single features location and form in novices. In Experiment 4 and 5, perceptual priming according the congruence of the single features location and form outperformed semantically-based response priming. Experiment 6 and 7 show that (in contrast to form priming) the observed location priming effect is rather robust and is also evident for an unexpected form or colour. In Experiment 8, location and form priming, which was additionally related to response priming, were directly compared to each other. Location priming was again stronger than form priming. Finally, Experiment 9 demonstrates that with the subliminal check detection task it is possible to induce response priming in novices when the confounding influences of location and form are absent. In the General discussion, I first summarized the findings. Second, I discuss possible underlying mechanisms of different subliminal perception in experts and novices. Third, I focus on subliminal perceptual priming in novices, especially on the impact of the features location and form. And finally, I discuss a framework, the action trigger account that integrates the different results of the present work.
The present work reviews the experimental literature on the acute effects of alcohol on human behaviour related to driving performance. A meta-analysis was conducted which includes studies published between 1954 and 2007 in order to provide a comprehensive knowledge of the substance alcohol. 450 studies reporting 5,300 findings were selected from over 12,000 references after applying certain in- and exclusion criteria. Thus, the present meta-analysis comprises far more studies than reviews on alcohol up to now. In the selected studies, different performance tests were conducted which were relevant for driving. The classification system used in this work assigns these tests to eight categories. The main categories consist of several sub categories classifying the tasks more precisely. The main categories were: (1) visual functions, (2) attention (including vigilance), (3) divided attention, (4) en-/decoding (including information processing and memory), (5) reaction time (including simple reaction time and choice reaction time), (6) psychomotor skills, (7) tracking and (8) driving. In addition to the performance aspect, the classification system takes into account mood and social behaviour variables related to driving safety like tiredness or aggression. Following the evaluation method of vote-counting, the number of significant findings and the number of non-significant findings were summarised per blood alcohol concentration (BAC) group. Thereby, a quantitative estimation of the effects of alcohol depending on the BAC was established, the so-called impairment function, which shows the percentage of significantly impaired findings. In order to provide a general overview of alcohol effects on driving-related performance, a global impairment function was established by aggregating all performance findings. The function is nearly linear with about 30% significant findings at a BAC of 0.05% and 50% significant findings at a BAC of 0.08%. In addition, more specific impairment functions considering only the findings of the single behavioural categories were calculated. The results revealed that impairment depends not only on the BAC, but also clearly differs between most of the performance categories. Tracking and driving performance were most affected by alcohol with impairment beginning at very low BACs of 0.02%. Also psychomotor skills were considerably affected by rather low BACs. Impairment of visual functions and information processing occurred at BACs of 0.04% and increased substantially with higher BACs. Impairment in memory tests could be found with very low BACs of 0.02%, but varied depending on the kind of memory. Performance decrements in divided attention tests could also be found with very low BACs in some studies. Attention started to be impaired at 0.04% BAC, but – as in vigilance tasks – considerable impairment only occurred at higher BACs. Choice reaction time was affected at lower BACs than simple reaction time, which was – together with the critical flicker fusion frequency – the least sensitive parameter to the effects of alcohol. To conclude, most skills which are relevant for the safe operation of a vehicle are clearly impaired by BACs of 0.05%, with motor functions being more affected than cognitive functions and complex tasks more than simple tasks. Generally, the results provided no evidence of a threshold effect for alcohol. There was no driving-related performance category for which a sudden transition from unimpaired to impaired occurred at a particular BAC level. In addition, a comparison was made between the present meta-analysis and two reviews of Moskowitz (Moskowitz & Fiorentino, 2000; Moskowitz & Robinson, 1988). Moskowitz reported much lower BACs at which performance was impaired. The reasons for this discrepancy lies in a different way to review scientific findings. On the one hand, Moskowitz focused on significant findings when selecting studies and findings for his reviews. On the other hand, the evaluation method used by Moskowitz ignored non-significant findings and counted each study once at the lowest BAC for which impairment was found. Those non-significant findings are as important as the significant ones in order to determine thresholds of impairment. Therefore, in contrast to Moskowitz, the present work describes the effects of alcohol with functions considering also the non-significant findings. The significance of the non-significant is emphasized with respect to the selection procedure as well as to the evaluation method.
Background:
This study investigated the relation between social desirability and self-reported physical activity in web-based research.
Findings:
A longitudinal study (N = 5,495, 54% women) was conducted on a representative sample of the Dutch population using the Marlowe-Crowne Scale as social desirability measure and the short form of the International Physical Activity Questionnaire. Social desirability was not associated with self-reported physical activity (in MET-minutes/week), nor with its sub-behaviors (i.e., walking, moderate-intensity activity, vigorous-intensity activity, and sedentary behavior). Socio-demographics (i.e., age, sex, income, and education) did not moderate the effect of social desirability on self-reported physical activity and its sub-behaviors.
Conclusions:
This study does not throw doubt on the usefulness of the Internet as a medium to collect self-reports on physical activity.
The present study investigated event-related brain potentials elicited by true and false negated statements to evaluate if discrimination of the truth value of negated information relies on conscious processing and requires higher-order cognitive processing in healthy subjects across different levels of stimulus complexity. The stimulus material consisted of true and false negated sentences (sentence level) and prime-target expressions (word level). Stimuli were presented acoustically and no overt behavioral response of the participants was required. Event-related brain potentials to target words preceded by true and false negated expressions were analyzed both within group and at the single subject level. Across the different processing conditions (word pairs and sentences), target words elicited a frontal negativity and a late positivity in the time window from 600-1000 msec post target word onset. Amplitudes of both brain potentials varied as a function of the truth value of the negated expressions. Results were confirmed at the single-subject level. In sum, our results support recent suggestions according to which evaluation of the truth value of a negated expression is a time-and cognitively demanding process that cannot be solved automatically, and thus requires conscious processing. Our paradigm provides insight into higher-order processing related to language comprehension and reasoning in healthy subjects. Future studies are needed to evaluate if our paradigm also proves sensitive for the detection of consciousness in non-responsive patients.
The limbic system and especially the amygdala have been identified as key structures in emotion induction and regulation. Recently research has additionally focused on the influence of prefrontal areas on emotion processing in the limbic system and the amygdala. Results from fMRI studies indicate that the prefrontal cortex (PFC) is involved not only in emotion induction but also in emotion regulation. However, studies using fNIRS only report prefrontal brain activation during emotion induction. So far it lacks the attempt to compare emotion induction and emotion regulation with regard to prefrontal activation measured with fNIRS, to exclude the possibility that the reported prefrontal brain activation in fNIRS studies are mainly caused by automatic emotion regulation processes. Therefore this work tried to distinguish emotion induction from regulation via fNIRS of the prefrontal cortex. 20 healthy women viewed neutral pictures as a baseline condition, fearful pictures as induction condition and reappraised fearful pictures as regulation condition in randomized order. As predicted, the view-fearful condition led to higher arousal ratings than the view-neutral condition with the reappraise-fearful condition in between. For the fNIRS results the induction condition showed an activation of the bilateral PFC compared to the baseline condition (viewing neutral). The regulation condition showed an activation only of the left PFC compared to the baseline condition, although the direct comparison between induction and regulation condition revealed no significant difference in brain activation. Therefore our study underscores the results of previous fNIRS studies showing prefrontal brain activation during emotion induction and rejects the hypothesis that this prefrontal brain activation might only be a result of automatic emotion regulation processes.
Several studies have investigated the neural responses triggered by emotional pictures, but the specificity of the involved structures such as the amygdala or the ventral striatum is still under debate. Furthermore, only few studies examined the association of stimuli’s valence and arousal and the underlying brain responses. Therefore, we investigated brain responses with functional magnetic resonance imaging of 17 healthy participants to pleasant and unpleasant affective pictures and afterwards assessed ratings of valence and arousal. As expected, unpleasant pictures strongly activated the right and left amygdala, the right hippocampus, and the medial occipital lobe, whereas pleasant pictures elicited significant activations in left occipital regions, and in parts of the medial temporal lobe. The direct comparison of unpleasant and pleasant pictures, which were comparable in arousal clearly indicated stronger amygdala activation in response to the unpleasant pictures. Most important, correlational analyses revealed on the one hand that the arousal of unpleasant pictures was significantly associated with activations in the right amygdala and the left caudate body. On the other hand, valence of pleasant pictures was significantly correlated with activations in the right caudate head, extending to the nucleus accumbens (NAcc) and the left dorsolateral prefrontal cortex. These findings support the notion that the amygdala is primarily involved in processing of unpleasant stimuli, particularly to more arousing unpleasant stimuli. Reward-related structures like the caudate and NAcc primarily respond to pleasant stimuli, the stronger the more positive the valence of these stimuli is.
Brain–computer interfaces (BCIs) enable paralyzed patients to communicate; however, up to date, no creative expression was possible. The current study investigated the accuracy and user-friendliness of P300-Brain Painting, a new BCI application developed to paint pictures using brain activity only. Two different versions of the P300-Brain Painting application were tested: A colored matrix tested by a group of ALS-patients (n = 3) and healthy participants (n = 10), and a black and white matrix tested by healthy participants (n = 10). The three ALS-patients achieved high accuracies; two of them reaching above 89% accuracy. In healthy subjects, a comparison between the P300-Brain Painting application (colored matrix) and the P300-Spelling application revealed significantly lower accuracy and P300 amplitudes for the P300-Brain Painting application. This drop in accuracy and P300 amplitudes was not found when comparing the P300-Spelling application to an adapted, black and white matrix of the P300-Brain Painting application. By employing a black and white matrix, the accuracy of the P300-Brain Painting application was significantly enhanced and reached the accuracy of the P300-Spelling application. ALS-patients greatly enjoyed P300-Brain Painting and were able to use the application with the same accuracy as healthy subjects. P300-Brain Painting enables paralyzed patients to express themselves creatively and to participate in the prolific society through exhibitions.
The aim of the present thesis was to explore how food deprivation and reward expectancy versus frustrative nonreward change implicit and explicit food-liking and food-wanting. As a result, Experiment 1-3 were successful in revealing that liking- and wanting-related associations toward food stimuli dissociate as a function of food deprivation, given that participants were not rewarded with real food during the experiment. More specifically, whereas food-deprived participants showed more wanting-related associations toward food stimuli than satiated participants, the liking-related associations did not differ across both conditions of hunger. Overall, this effect could be replicated in 3 experiments using different manipulations of nonreward versus reward expectancy. However, neither food deprivation nor nonreward were found to influence participants’ self-reported mood and frustration. Moreover, participants of Experiment 2 anticipating food consumption showed the same liking- and wanting-related responses due to food deprivation than participants in the nonreward condition. But providing participants with individual control over food consumption abolished the dissociation of liking- and wanting-related associations. In this condition, however, participants’ liking- and wanting-related associations were not moderated by need state, maybe due to the (partial) consumption of snack food before the implicit attitude assessment. This, in turn, may have reduced participants’ disposition to respond with more liking- and wanting-related associations when being hungry. Finally, Experiment 4 revealed that the presentation of need-relevant vs. need-irrelevant stimuli prompted different liking-related associations depending on the time participants had fasted before the experiment. Specifically, it could be demonstrated that whereas moderately-hungry compared to satiated participants responded with more positive associations toward need-relevant stimuli, 15 hours food-deprived participants responded with more negative associations compared to moderately-hungry and satiated participants. Respectively, a significant curvilinear function of need state was obtained. In addition, participants were found to immediately respond more negatively to need-irrelevant stimuli as soon as they became moderately hungry, evidencing devaluation effects (see Brendl, Markman, & Messner, 2003) to also occur on an implicit level of responding. Contrary to the implicit liking- and wanting-related evaluations, self-reported explicit food-liking and food-wanting did not dissociate as a function of food deprivation and nonreward, revealing that participants’ explicit self-reports of food-liking and food-wanting did not mirror their implicit responses. As the most important result, it could be demonstrated that explicit food-liking and food-wanting varied positively as a function of need state. The results were discussed on the background of different theoretical assumptions on the malleability of implicit and explicit need-relevant attitudes (e.g. motivational theories, frustrative nonreward).
Neuroplasticity is a term indicating structural and functional changes in the brain through the lifespan. In the present study, differences in the functional cortical activations between the musical talents and non-talents were investigated after a short-term practice of the visuomotor and auditory tasks. Visuomotor task consisted of the finger tapping sequences, while auditory task consisted of passive listening to the classical music excerpts. Non-talents were divided in two groups: trained non-talents who practiced the task prior to scanning and untrained non-talents who did not practice the task. Functional activations were obtained by the functional magnetic resonance imaging (fMRI) in a 1.5T Scanner. It was hypothesized that talents would exhibit different functional activations from non-talents in both tasks as a result of the long-term music practice, which would account for the brain plasticity. Decreased activation of the same areas in talents in respect to the non-talents as well as the activation of different areas between the talents and non-talents was hypothesized. In addition due to a plethora of previous studies showing increased activations in the primary motor cortex (M1) in musicians, as well as left inferior frontal gyrus (lIFG), increased activation of the M1 and lIFG in talents were hypothesized. Behavioral results did not reveal differences in performance among the three groups of subjects (talents, non-talents who practiced the task, and non-talents who did not practice the task). The main findings from imaging results of the visuomotor task confirmed the hypothesis of the increased activation in the M1 in talents. Region of interest analyses of the lIFG revealed the highest activation in the untrained non-talents, lower activation in talents, and least activation in the trained non-talents. Posthoc imaging analyses revealed higher activations in the cerebella of subjects who practiced the visuomotor task. For the auditory task, the effect of auditory practice was observed in the right inferior frontal gyrus (rIFG). These results should be interpreted with caution due to the absence of behavioral differences among the groups.
In order to unify two major theories of moral judgment, a novel task is employed which combines elements of Kohlberg´s stage theory and of the theory of information integration. In contrast to the format of Kohlberg´s moral judgment interview, a nonverbal and quantitative response which makes low demands on verbal facility was used . Moral informers differing in value, i.e. high and low, are presented. The differences in effect of those two pieces of information should be substantial for a person at that specific moral stage, but small for a person at a different stage. Hence, these differences may diagnose the person's moral stage in the simplest possible way as the two levels of each of the thoughts were about typical content of the four Kohlbergian preconventional and conventional stages. The novel task allowed additionally to measure the influence of another moral concept which was about the non-Kohlbergian moral concept of recompense. After a training phase, pairs of those thoughts were presented to allow for the study of integration and individual differences. German and Korean children, 8, 10, and 12 years in age, judged deserved punishment. The patterns of means, correlations and factor loadings showed that elements of both theories can be unified, but produced unexpected results also. Additive integration of each of the two pairs of moral informers appeared, either with two Kohlbergian moral informers or with another Kohlbergian moral informer in combination with information about recompense. Also cultural independence as well as dependence, developmental changes between 8 and 10 years, and an outstanding moral impact of recompense in size and distinctiveness were observed.
The aim of this project was to investigate whether reflex-like innate facial reactions to tastes and odors are altered in patients with eating disorders. Qualitatively different tastes and odors have been found to elicit specific facial expressions in newborns. This specificity in newborns is characterized by positive facial reactions in response to pleasant stimuli and by negative facial reactions in response to unpleasant stimuli. It is, however, unclear, whether these specific facial displays remain stable during ontogeny (1). Despite the fact that several studies had shown that taste-and odor-elicited facial reactions remain quite stable across a human’s life-span, the specificity of research questions, as well as different research methods, allow only limited comparisons between studies. Moreover, the gustofacial response patterns might be altered in pathological eating behavior (2). To date, however, the question of whether dysfunctional eating behavior might alter facial activity in response to tastes and odors has not been addressed. Furthermore, changes in facial activity might be linked to deficient inhibitory facial control (3). To investigate these three research questions, facial reactions in response to tastes and odors were assessed. Facial reactions were analyzed using the Facial Action Coding System (FACS, Ekman & Friesen, 1978; Ekman, Friesen, & Hager, 2002) and electromyography.
In order to survive, organisms avoid threats and seek rewards. Classical conditioning is a simple model to explain how animals and humans learn associations between events that allow them to predict threats and rewards efficiently. In the classical conditioning paradigm, a neutral stimulus is paired with a biologically significant event (the unconditioned stimulus – US). In virtue of this association, the neutral stimulus acquires affective motivational properties, and becomes a conditioned stimulus (CS+). Defensive responses emerge for pairings with an aversive US (e.g., pain), and appetitive responses emerge for pairing with an appetitive event (e.g., reward). It has been observed that animals avoid a CS+ when it precedes an aversive US during a training phase (CS+ US; forward conditioning); whereas they approach a CS+ when it follows an aversive US during the training phase (US CS+; backward conditioning). These findings indicate that the CS+ acquires aversive properties after a forward conditioning, whereas acquires appetitive properties after a backward conditioning. It is thus of interest whether event timing also modulates conditioned responses in such an opponent fashion in humans, who are capable of explicit cognition about the associations. For this purpose, four experiments were conducted in which a discriminative conditioning was applied in groups of participants that only differed in the temporal sequence between CS+ onset and US onset (i.e., the interstimulus interval – ISI). During the acquisition phase (conditioning), two simple geometrical shapes were presented as conditioned stimuli. One shape (CS+) was always associated with a mild painful electric shock (i.e., the aversive US) and the other one (CS-) was never associated with the shock. In a between-subjects design, participants underwent either forward or backward conditioning. During the test phase (extinction), emotional responses to CS+ and CS- were tested and the US was never presented. Additionally, a novel neutral shape (NEW) was presented as control stimulus. To assess cognitive components, participants had to rate both the valence (the degree of unpleasantness or pleasantness) and the arousal (the degree of calmness or excitation) associated with the shapes before and after conditioning. In the first study, startle responses, an ancestral defensive reflex consisting of a fast twitch of facial and body muscles evoked by sudden and intense stimuli, was measured as an index of stimulus implicit valence. Startle amplitude was potentiated in the presence of the forward CS+ whilst attenuated in the presence of the backward CS+. Respectively, the former response indicates an implicit negative valence of the CS+ and an activation of the defensive system; the latter indicated an implicit positive valence of the CS+ and an activation of the appetitive system. In the second study, the blood-oxygen level dependent (BOLD) response was measured by means of functional magnetic resonance imaging (fMRI) to investigate neural responses after event learning. Stronger amygdala activation in response to forward CS+ and stronger striatum activation in response to backward CS+ were found in comparison to CS-. These results support the notion that the defensive motivational system is activated after forward conditioning since the amygdala plays a crucial role in fear acquisition and expression. Whilst the appetitive motivational system is activated after backward conditioning since the striatum plays a crucial role in reward processing. In the third study, attentional processes underlying event learning were observed by means of steady-state visual evoked potentials (ssVEPs). This study showed that both forward and backward CS+ caught attentional resources. More specifically, ssVEP amplitude was higher during the last seconds of forward CS+ that is just before the US, but during the first seconds of backward CS+ that is just after the US. Supposedly, attentional processes were located at the most informative part of CS+ in respect to the US. Participants of all three studies rated both forward and backward CS+ more negative and arousing compared to the CS-. This indicated that event timing did not influence verbal reports similarly as the neural and behavioral responses indicating a dissociation between the explicit and implicit responses. Accordingly, dual process theories propose that human behavior is determined by the output of two systems: (1) an impulsive implicit system that works on associative principles, and (2) a reflective explicit system that functions on the basis of knowledge about facts and values. Most importantly, these two systems can operate in a synergic or antagonistic fashion. Hence, the three studies of this thesis congruently suggest that the impulsive and the reflective systems act after backward association in an antagonistic fashion. In sum, event timing may turn punishment into reward in humans even though they subjectively rate the stimulus associated with aversive events as being aversive. This dissociation might contribute to understand psychiatric disorders, like anxiety disorders or drug addiction.
The thesis deals with the question which motivation direction—approach or avoidance—is connected to the emotion relief—a positive, low-arousal emotion, which is caused by an expected or nonexpected, motive-consistent change for the better, thus caused by the absence of an aversive stimulus. Based on the idea of postulating different levels of approach avoidance motivation, the Reflective-Impulsive Model of Behavior (RIM, Strack & Deutsch, 2004) is applied to relief and approach avoidance. The RIM differentiates between an impulsive and a reflective system of information processing, with both systems working in relative independence from each other. Two central variables moderate the relation between relief and approach avoidance. The first is the psychological system in which approach avoidance is processed and assessed. Two levels of approach avoidance are distinguished: an impulsive distance orientation (distance change in relation to specific stimuli) and a reflective goal orientation (attainment of positive versus avoidance of negative end states). The second is the psychological system in which relief developed: In the impulsive system, relief develops as the affect that is conditioned to the absence of negative states; in the reflective system, relief develops as a result of goal-oriented behaviour of controlling or preventing of negative stimulation. The thesis looks at both moderators (level of approach avoidance and psychological system of development of relief) at once. The central prediction for the impulsive distance orientation is: Relief leads to an approach distance orientation (distance reduction), independent from the system in which relief develops. The central prediction for the reflective goal orientation is: Relief leads to an avoidance goal orientation (control of negative end states). This latter prediction is only made for the case when relief was caused by (develops in) the reflective system, that is by one’s own, goal-directed behaviour; it is further necessary for an avoidance goal orientation that the relief state cannot certainly reached, instead there always has to uncertainty in the control of negative states. The methodology in the thesis is based on studies of aversive conditioning. In most studies, a differentiation paradigm is applied. The impulsive relief is operationalized via a classically conditioned relief (aversive CS-), whereas the reflective relief is operationalized via an active avoidance paradigm which ensures the methodological comparability of “reflective relief” to “impulsive relief”. The predictions are as follows: Prediction A: Relief will elicit positive affective valence and an approach distance orientation. This should be true for both relief that is caused by the impulsive system and for relief that is caused by the reflective system (Experiments 2-3). Prediction B: More positive valence of relief—caused by a larger change of affective states—will elicit a stronger approach distance orientation (Experiment 4). Prediction C: Relief caused by the impulsive system will not elicit a specific goal orientation (Experiment 5). Prediction D: Uncertain self-induced relief—caused by the reflective system—will elicit an avoidance goal orientation (Experiments 6-7). In addition, Experiment 1 validated the conditioning paradigm used for the elicitation of relief. The experiments in the thesis support all predictions made in the theoretical part. The work has implications for the assumptions made in the RIM (Strack & Deutsch, 2004). In the impulsive system, the affective valence determines approach avoidance orientation (e.g., R. Neumann & Strack, 2000), the reflective goal not playing an important role. Relief elicits an approach orientation in the impulsive system. In the reflective system, the active goal is decisive for the approach avoidance orientation. Uncertain self-caused relief elicits an avoidance goal orientation in the reflective system. The studies of the thesis thus support and validate the assumptions made in the RIM (Strack & Deutsch, 2004) in the specific field of motivational direction.
The aim of the current work was to enhance the understanding of the relationship between goals and the self. More specifically, I wanted to achieve three things. First, I developed an implicit measure of self-activation (SA) based on response latencies to avoid the problems of traditional measures of self-activation (i.e., demand effects, self-presentation concerns). Therefore, two studies were conducted in which increased self-activation, induced by classic self-manipulations, was measured with a newly developed picture task. Thereby it was assumed that individuals would react faster to photographs of themselves when the self was activated than when it was not. Second, I aimed to demonstrate that there exists a close connection between personal goals and the self. Despite being inherent in several theories, this assumption has never been tested directly before. It was hypothesized that thinking about personal goals should activate the self, resulting in faster reactions in the newly developed measure of SA, i.e., quicker responses to the self-pictures. Third, it was investigated whether goals and the self are linked in a bidirectional fashion; according to the reported findings, it seems to be functional for individuals’ self-regulation and goal pursuit to develop such a link. To provide evidence for the bidirectionality of the relationship, it was hypothesized that in conditions of high SA, it should be more likely personal evaluations to be construed as goals; this goal activation should result in higher accessibility of goal-related knowledge, stronger approach motivational tendencies towards goal-related targets, and more goal-directed behavior. The obtained results endorse the applicability of the picture task as implicit method to measure increased SA and also corroborate the core hypothesis, namely that personal goals and the self are inherently connected and that they are linked in a bidirectional fashion.
Mediators of Social Anxiety - External Social Threat-Cues vs. Self-Related Negative Cognitions
(2009)
Based on a review of models and empirical findings a working model is proposed, suggesting that self-related negative cognitions and biased processing of external social threat-cues are mediators of social anxiety. Hypotheses derived from this model were tested in three experiments. The first experiment examined whether levels of trait social anxiousness predicted fearful responding to external social threat-cues (angry vs. neutral and happy facial expressions) during social evaluation. Higher trait social anxiousness predisposes to an inward focus on one’s fear reaction to social threat. Using this strategy was expected to enhance fearful responding to angry facial expressions. A strategy of identifying with angry faces was expected to counteract fearful responding, but was expected to fail more often with increasing levels of trait social anxiousness. To examine these hypotheses, affective modulation of the startle eye-blink was assessed in forty-four undergraduate students. This measure served as a probe into the activation of brain structures involved in the automatic evaluation of environmental threat-cues. Trait and state anxiety as well as explicit emotional responding to the stimuli were assessed with questionnaires and ratings. Processing angry faces potentiated startle amplitudes as expected. Low arousal induced by the stimuli was a probable reason, why startle potentiation to happy faces emerged instead of attenuation. Trait social anxiousness and the cognitive strategies did not influence these effects. Yet, increased trait social anxiousness predicted decreased startle latency, indicating motor hyper-responsivity, which is part of the clinical representation of social anxiety disorder (SAD). Processing facial expressions and identifying with them disrupted this association. Previous studies support that similar strategies may enhance treatment of SAD. Individuals with SAD were expected to respond with increased arousal to external social threat-cues. Therefore, the second experiment examined whether nine individuals with SAD showed attentional (prepulse inhibition, PPI) or affective startle modulation to angry as compared to neutral and happy facial expressions. Corrugator supercilii activity was assessed as a behavioral indicator for effects of facial expressions. The remaining setup resembled the first experiment. Facial expressions did not modulate the startle reflex, but corrugator supercilii activity was sensitive to facial valence. However, the effects were not related to trait social anxiousness. Apparently, angry facial expressions do not act as phobic stimuli for individuals with SAD. The third experiment examined whether focusing on self-related negative cognitions or biased processing of external social threat-cues mediates relationships between trait social anxiety and anxious responding in a socially challenging situation. Inducing self-related negative cognitions vs. relaxation was expected to reveal a functional dependency on the supposed mediation in a multivariate assessment of criteria of the working model. Within this design, the impact of external social threat-cues (facial expressions and emotional words) was compared to control stimuli and context effects, using the startle paradigm. The findings provide first evidence for full statistical mediation of the associations between trait social anxiety and self-reported anxiety as well as parasympathetic withdrawal by self-related negative cognitions, when thirty-six undergraduate students anticipated public speaking. Apprehensive arousal, as indicated by increased skin conductance levels and heart rate, was present in all participants. Observer ratings of behavior during public speaking matched the self-rated quality of the performance. None of these measures were correlated with trait social anxiousness. Startle amplitude correlated with state and trait social anxiety, but was no mediator. Finally, there was no affective modulation of the startle amplitude by external social threat-cues. These studies advance both our current understanding of the factors that mediate social anxiety responses to situations and our knowledge of the physiological and anatomical mechanisms involved in social anxiety. Based on these findings a revised version of the working model on mediators of social anxiety is proposed in the hope it may aid further research for the ultimate goal of developing an empirically validated functional anatomical model of social anxiety.
The present approach highlights a procedural account of intuitive judgments. In intuitions of hidden semantic coherence, people can intuitively detect whether a word triad has a common remote associate (coherent) or not (incoherent) before, and independently from actually retrieving the common associate. The present fluency-affect intuition model (FAIM) maintains that semantic coherence increases the processing fluency for coherent compared to incoherent triads, and that this increased fluency triggers brief and subtle positive affect, which is the experiential basis of these intuitions. Published work concerning 25 experiments is reviewed that gathered empirical support for this model. Furthermore, the impact of fluency and affect was also generalized to intuitions of visual coherence, and intuitions of grammaticality in an artificial grammar learning paradigm.
Humans and other animals share choice preference for smaller-but-sooner over later-but-larger rewards, indicating that the subjective value of a reward is discounted as a function of time. This phenomenon referred to as delay discounting (DD), represents one facet of impulsivity which is inherently connected with reward processing and, within a certain range, adaptive. Maladaptive levels, however, can lead to suboptimal decision-making and represent important characteristics of psychopathologies such as attention-deficit/hyperactivity disorder (ADHD). In line with a proposed influence of dysregulated dopamine (DA) levels on impulsivity, neural structures involved in DD (the ventral-striatum [VS]; orbitofrontal cortex [OFC]) are highly innervated by dopaminergic neurons. However, studies explicitly testing the triadic interplay of dopaminergic neurotransmission, impulsivity and brain activation during intertemporal choice are missing. Therefore, the first study of the thesis examined the effect of different DA-bioavailability levels, indicated by a genetic polymorphism (Val158Met) in the gene of the catechol-O-methyltransferase, on the association of delay discounting and OFC activation. OFC response to monetary rewards that varied by delay-to-delivery was recorded with functional near-infrared spectroscopy (fNIRS) in a sample of 49 healthy human subjects. The results suggest a DA-related enhancement in OFC function from low (low DA level) to partial (intermediate DA level) and full (high DA level) reward delay sensitivity. Furthermore, DA-bioavailability was shown to moderate the association of neural reward delay sensitivity and impulsivity: OFC reward delay sensitivity was strongly correlated with impulsivity at intermediate DA-levels, but not at low or high DA-levels where impulsivity was related to delay-independent OFC amplitudes. It is concluded that DA-level should be considered as a crucial factor whenever impulsivity-related brain activation, in particular to reward delay, is examined in healthy subjects. Dysfunctional reward processing, accompanied by a limited ability to tolerate reward delays (delay aversion), has been proposed as an important feature in ADHD putatively caused by striatal hypo-dopaminergia. Therefore, the aim of the second study of this thesis was to examine subcortical processing of reward delays and to test for neural indicators of a negative emotional response to delay periods. Using functional magnetic resonance imaging (fMRI), brain activation in adult patients with ADHD (n=14) and healthy control subjects (n=12) was recorded during the processing of immediate and delayed rewards. Compared with healthy control subjects, hyporesponsiveness of the VS reward system was evident in patients with ADHD for both immediate and delayed rewards. In contrast, delayed rewards evoked hyperactivation in the dorsal caudate nucleus and the amygdala of ADHD patients, corroborating the central predictions of the delay aversion hypothesis. In combination both studies support the conception of a close link between delay discounting, brain activation and dopaminergic neurotransmission. The results implicate that studies on neural correlates of DD have to account for the DA-bioavailability level and for a negative emotional response to reward delays.
Encoding Redundancy for Task-dependent Optimal Control : A Neural Network Model of Human Reaching
(2008)
The human motor system is adaptive in two senses. It adapts to the properties of the body to enable effective control. It also adapts to different situational requirements and constraints. This thesis proposes a new neural network model of both kinds of adaptivity for the motor cortical control of human reaching movements, called SURE_REACH (sensorimotor unsupervised learning redundancy resolving control architecture). In this neural network approach, the kinematic and sensorimotor redundancy of a three-joint planar arm is encoded in task-independent internal models by an unsupervised learning scheme. Before a movement is executed, the neural networks prepare a movement plan from the task-independent internal models, which flexibly incorporates external, task-specific constraints. The movement plan is then implemented by proprioceptive or visual closed-loop control. This structure enables SURE_REACH to reach hand targets while incorporating task-specific contraints, for example adhering to kinematic constraints, anticipating the demands of subsequent movements, avoiding obstacles, or reducing the motion of impaired joints. Besides this functionality, the model accounts for temporal aspects of human reaching movements or for data from priming experiments. Additionally, the neural network structure reflects properties of motor cortical networks like interdependent population encoded body space representations, recurrent connectivity, or associative learning schemes. This thesis introduces and describes the new model, relates it to current computational models, evaluates its functionality, relates it to human behavior and neurophysiology, and finally discusses potential extensions as well as the validity of the model. In conclusion, the proposed model grounds highly flexible task-dependent behavior in a neural network framework and unsupervised sensorimotor learning.
Assessment of emotional detachment in psychopathy via self-report and an emotion detection task
(2008)
The personality construct of psychopathy is subject of growing research, but data on psychopathy in female incarcerated and in non-institutionalized samples are rare. In this thesis emotional detachment as one factor of psychopathy is investigated in general population, in patients and in incarcerated samples. After verifying the validity of the Psychopathy Personality Inventory Revised (PPI-R) measuring emotional detachment, the sensitivity of the questionnaire concerning emotional detachment has been proven. Additionally it has been shown that symptoms of attention deficit and hyperactivity disorder can be distinguished from psychopathic traits by emotional detachment. In addition, these results confirm the core role of the feature emotional detachment for psychopathy. Furthermore, two emotion recognition tasks have been conducted in a criminal female inpatients sample. Compared to the low psychopathic patients, the high psychopathic patients showed deficits in categorization only in shortly presented sad facial expressions, but rated emotional facial expressions as less arousing. These results point to emotional detachment as a core characteristic of psychopathy, and is specific even in non-incarcerated and female incarcerated samples. It can be measured with the PPI-R as well as with emotion detection tasks.
The main goals of the present thesis were to investigate how food deprivation influences food related disgust and to identify mental mechanisms that might underlie alterations in food related disgust. For this purpose, 9 studies were conducted that employed direct and indirect measures of attitudes, biological measures of affect as well as measures of real eating behavior and food choice, and compared responses of deprived and non deprived subjects on each of these measures. Spontaneous facial reactions were assessed via EMG and revealed that food deprived subjects showed weaker disgust reactions than satiated participants when being confronted with photographs of disgusting foods. Interestingly, deprived and non deprived subjects evaluated disgusting foods equally negative on a conscious level of information processing, indicating that food deprivation has the potential to attenuate food related disgust irrespective of conscious evaluations. Furthermore, it was found that food deprived participants readily consumed disgust related foods (“genetically modified foods”), while satiated participants rejected those foods. Again, no difference emerged between deprived and non deprived subjects in respect to their conscious evaluations of genetically modified foods (that were negative in both experimental groups). The dissociation between conscious evaluations and actual eating behavior that was observed amongst food deprived participants resembles the dissociation between conscious evaluations and facial reactions, thereby corroborating the assumption that alterations in food related disgust might directly influence eating behavior without changing conscious evaluations of foods. The assumption that a shift in automatic attitudes towards disgusting foods might be responsible for these effects received only partial support. That is, there was only a non significant tendency for food deprived subjects to evaluate disgusting foods more positive than satiated subjects on an automatic level of information processing. Instead, the results of the present thesis suggest that food deprived subjects exhibit a stronger motivation than satiated subjects to approach disgusting foods immediately. More precisely, food deprived participants exhibited strong approach motivational tendencies towards both, palatable and disgusting foods in an “Approach- Avoidance Task” whereas satiated participants only approached palatable (but not disgusting) foods on an automatic level of information processing. Moreover, food deprivation seems to change the subjective weighting of hedonic and functional food attributes in the context of more elaborated decisions about which foods to pick for consumption and which foods to reject. It was found that individual taste preferences were of minor importance for food deprived subjects but very important for satiated subjects when actually choosing between several food alternatives. In contrast, functional food attributes (e.g., immediate availability of a given food, large portion size) were more important selection criteria for food deprived subjects than for satiated subjects. Thus, food deprived participants were less picky than satiated participants, but showed a clear preference for those food alternatives that were functional in ending a state of food deprivation quickly – even if this meant choosing a food that was not considered tasty. Taken together, the present thesis shows that physiological need states (e.g., food deprivation) are tightly linked to the affective and motivational processing of need relevant cues. This link is so strong that food deprivation even modulates affective and motivational reactions as well as eating behavior and choice behavior towards disgusting (but need relevant) foods.
One of the major drawbacks in the implementation of intelligent tutoring systems is the limited capacity to process natural language and to automatically deal with unexpected or unknown vocabulary. Latent Semantic Analysis (LSA) is a statistical technique of automatic language processing, which can attenuate the “language barrier” between humans and tutoring systems. LSA-based intelligent tutoring systems address the goals of modelling human tutoring dialogues (AutoTutor), enhancing text comprehension and summarisation skills (State-The-Essence, Summary Street®, conText, Apex), training of comprehension strategies (iStart, a French system in development) and improving story and essay writing (Write To Learn, Select-a-Kibitzer, StoryStation). The systems are reviewed concerning their efficacy in modelling skilled human tutors and regarding their effects on the learner.
Cognitive views of the psychopathology of anxiety propose that attentional biases toward threatening information play a substantial role in the disorders’ etiology and maintenance. For healthy subjects, converging evidence show that threatening stimuli attract attention and lead to enhanced activation in visual processing areas. It is assumed that this preferential processing of threat occurs at a preattentive level and is followed by fast attentional engagement. High-anxious individuals show augmented tendencies to selectively attend toward fear-relevant cues (Mathews, 1990) and exhibit elevated neural processing of threatening cues compared to non-anxious individuals (Dilger et al., 2003). Regarding attentional biases in high-anxious subjects, it remains unanswered up to now whether initial engagement of attention toward threat or difficulties to disengage from threat is an underlying mechanism. Furthermore, little is known whether the preferential (attentive) processing of threatening cues does influence perceptional outcomes of anxious subjects. In order to directly study separate components of attentional bias the first study of this dissertation was a combined reaction time and eye-tracking experiment. Twenty one spider phobic patients and 21 control participants were instructed to search for a neutral target while ignoring task-irrelevant abrupt-onset distractor circles which contained either a small picture of a spider (phobic), a flower (non-phobic, but similar to spiders in shape), a mushroom (non-phobic, and not similar to spiders in shape), or small circles with no picture. As expected, patients’ reaction times to targets were longer on trials with spider distractors. However, analyses of eye movements revealed that this was not due to attentional capture by spider distractors; patients more often fixated on all distractors with pictures. Instead, reaction times were delayed by longer fixation durations on spider distractors. This result does not support automatic capture of attention by phobic cues but suggests that phobic patients fail to disengage attention from spiders. To assess whether preferential processing of phobic cues differentially affects visual perception in phobic patients compared to healthy controls, the second study of this dissertation used a binocular rivalry paradigm, where two incompatible pictures were presented to each eye. These pictures cannot be merged to a meaningful percept and temporarily, one picture predominates in conscious perception whereas the other is suppressed. 23 spider phobic patients and 20 non-anxious control participants were shown standardized pictures of spiders or flowers, each paired with a neutral pattern under conditions of binocular rivalry. Their task was to continuously indicate the predominant percept by key presses. Analyses show that spider phobic patients perceived the spider picture more often and longer as dominant compared to non-anxious control participants. Thus, predominance of phobic cues in binocular rivalry provides evidence that preferential processing of fear-relevant cues in the visual system actually leads to superior perception. In combination both studies support the notion that phobic patients process phobic cues preferentially within the visual system resulting in enhanced attention and perception. At early stages of visual processing, this is mainly reflected by delayed attentional disengagement and across time, preferential processing leads to improved perception of threat cues.
Frustration has been investigated since the early beginnings of psychological research. Yet, it is still unclear how frustration influences the two main parameters of motivation, i.e., orientation (approach-avoidance) and intensity. Some theories propose that controllable frustration increases approach motivation, thereby maintaining motivational intensity. In contrast, other theories propose that the perception of obstacles immediately elicits an avoidance orientation because of the negative valence of the perceptual input. Yet, the latter theories can not explain how motivational intensity is maintained upon encountering obstacles. The aim of the present thesis is to integrate previous contradicting assumptions by describing the influence of frustration on motivational orientation and motivational intensity on the basis of a two-system model of behavior. The definition of frustration as an unexpected obstacle blocking the attainment of an anticipated gratification implies that the obstacle is immediately perceived, whereas the goal is only represented in working memory. According to two-system models, these two types of representations influence different levels of behavior regulation. Whereas spontaneous approach-avoidance tendencies are mainly determined by the valence of the perceptual input, decisions to engage effort to reach the goal are based on knowledge about goals and appraisals of controllability of obstacles. Supporting this theorizing, six experiments demonstrated that frustration immediately activates avoidance tendencies. This was true for frustration of approach goals as well as for frustration of avoidance goals. Furthermore, this effect did not depend on the type of frustration feedback, and was found when approach-avoidance tendencies were measured after completion of goal pursuit as well as while overcoming frustration. In addition, approaching obstacles impaired performance in a subsequent task, suggesting that approaching obstacles consumed cognitive resources. This further supports the assumption that obstacles immediately activate avoidance tendencies. Furthermore, dispositional action-state orientation, which has been previously shown to moderate automatic affective reactions, influenced approach-avoidance tendencies, indicating that affect mediates the impact of frustration on behavioral tendencies. Finally, manipulations of controllability of frustration did not influence spontaneous approach-avoidance tendencies, but measures of motivational intensity such as decisions to engage more effort as well as activation of goal-relevant behavioral schemata. In sum, these findings support the assumptions that immediately elicited motivational orientations are mainly a function of the valence of perceptual input, whereas behavior to reach the goal (i.e. motivational intensity) is regulated by working memory representations such as appraisals of goal expectancy. Motivational orientations may serve to prepare organisms for quick reactions to sudden, unexpected occurrences, whereas behavior regulation based on goal appraisals may provide stability and flexibility in long-term goal pursuit.
This article describes a 2-systems model that explains social behavior as a joint function of reflective and impulsive processes. In particular, it is assumed that social behavior is controlled by 2 interacting systems that follow different operating principles. The reflective system generates behavioral decisions that are based on knowledge about facts and values, whereas the impulsive system elicits behavior through associative links and motivational orientations. The proposed model describes how the 2 systems interact at various stages of processing, and how their outputs may determine behavior in a synergistic or antagonistic fashion. It extends previous models by integrating motivational components that allow more precise predictions of behavior. The implications of this reflective–impulsive model are applied to various phenomena from social psychology and beyond. Extending previous dual-process accounts, this model is not limited to specific domains of mental functioning and attempts to integrate cognitive, motivational, and behavioral mechanisms.
One primary source for self-knowledge is social comparison. Often objective criteria for self-evaluations are not available or useful and therefore comparisons with other people play a crucial role in self-evaluations. But the question is whether social comparisons could indeed provide information about the self without consuming too much cognitive resources or time. Therefore, in this research I wanted to look at practice effects in social comparison and the particular significance of routine standards. Whereas traditional research on standard selection mostly focused on goal-oriented and strategic standard selection processes, this research sets out to integrate social cognitive knowledge, ideas, and methods. Researchers from many different fields agree that people’s behavior and thinking is not fully determined by rational choices or normative considerations. Quite the contrary, factors like knowledge accessibility, habits, procedural practice, stereotyping, categorization, and many more cognitive processes play an important role. The same may be true in social comparison and standard selection. In my research I demonstrate that efficiency concerns play an important role in social comparison. Since people may not be able to engage in a strategic standard selection whenever they engage in social comparison processes, there has to be a more efficient alternative. Using routine standards would be such an alternative. The efficiency advantage of routine standards may thereby be founded not only in the abandonment of a strategic but arduous standard selection process, but also in a higher efficiency of the comparison process itself. I therefore set out to show how the use of routine standards facilitates the social comparison processes. This was done in three steps. First, I replicated and improved our former research (Mussweiler & Rüter, 2003, JPSP) indicating that people really do use their best friends as routine standards to evaluate themselves. Second, I demonstrated that it is more efficient to compare with a routine standard than with another standard. In Studies 2 and 3 I therefore show that comparisons between the self and a routine standard (either a natural routine standard like the best friend or a experimentally induced routine standard based on practice) are faster and more efficient than comparisons with other standards. Finally, I looked at the underlying mechanism of the efficiency advantage of routine standards. The results of Studies 4 and 5 point out, that both general as well as specific practice effects occur with repeated comparisons. Whereas a specific practice effect implies the repeated processing of the same content (i.e., knowledge about the routine standard), general practice effects indicate that the pure process (i.e., comparing the self with a routine standard) becomes more efficient regardless whether new content (i.e., comparison relevant knowledge) has to be processed. Taken together, the efficiency advantage of routine standards during self-evaluation is based not only on the lack of necessity for an arduous standard selection, but is additionally supported by the facilitation of the comparison process itself. The efficiency of routine standards may provide an explanation as to why people base self-evaluations on comparisons with these standards and dispense with strategic considerations to select the most suitable standard.
143 9- and 10-year-oId children were classified into high- and Jow-IQ groups and given 4 different sort/recall lists (baseline, training, near [immediate] extension, far [l-week] extension) to assess training and extension of an organizational memory strategy. All children received categorized items of moderate typicality for Phases 1, 3, and 4. For Phase 2, children were assigned to either a training or control group, with half of the children in each group receiving category typical items and the others category atypical items. Levels of recall, sorting, and clustering were greater in Phase 2 for high-IQ children, for the typical lists, and for trained children. Both the high- and low-IQ children trained with typical items continued to show high levels of recall on the near extension phase. No group of subjects maintained high levels of recall after 1 week, although levels of sorting and/or clustering on the extension trials remained high for all groups of subjects except the low-IQ control children. This latter pattern (elevated sorting/clustering with low levels of recall) is an indication of a utilization deficiency, a phase in strategy development when children use a strategy but gain little or no benefit n performance. The results provide evidence for IQ, training, and material effects in the demonstration of a utilization deficiency.
ln two experiments, male rats were observed in pairs under different environmental stimulations in an open field. ln Experiment 1, white noise of 85 dB(A) reduced social activities and increased defecation compared to 75 dB(A) and 65 dß(A). ln Experiment 2, the illumination of the open field was varied in addition to a variation of the noise intensity. Again, 85 dB(A) as compared to 50 dB(A) reduced social activities and increased defecation, but also led to changes in non-social behaviours such as sniffing, grooming, and rearing. ln contrast, 400 lx did not differ substantially in its effects from 40 lx in any of the observed behavioural categories. Altogether, the behaviour pattern under 85 dß(A) white noise cannot satisfactorily be explained only by increased anxiety or fear. Alternative explanations are discussed.
In a study intended to replicate and extend the findings from a recent experiment by Schneider and Bjorklund (1992), the expert/novice paradigm was used with second- and fourth-grade children in a sort/recall task. Children were classified as experts or novices for their knowledge of baseball, then given two sort/recall tasks, with a list consisting of either baseball or nonbaseball terms. Experts recalled more than novices on the baseball list only. While both groups used organizational strategies at sorting on the nonbaseball list, experts were marginally more strategic than novices on the baseball list, and no differences were found between the groups on either list for clustering. Baseball experts used more adultlike categories, suggesting that their enhanced levels of recall were attributed in part to strategy use, although there was also evidence that most of the substantial recall difference between the groups was attributed to item-specific effects associated with a more elaborated knowledge base. A second experiment using fifth-grade children on a multitrial sort/recall task using the baseball list also found increased recall by experts, and also found evidence of strategic behavior at the sort phase for trials 3 and 4.
Second- and fourth-grade children were classified according to their knowledge of soccer (experts vs. novices) and IQ (high vs. low), and given 2 sort-recall tasks. One task included items related to the game of soccer and the other included items from familiar natural language categories. Previous research has shown that expertise in a snbject can compensate for low levels of performance on text comprehension tasks. Our results, the flrst examing the effects of both expertise and intelligence on a strategic memory task, were that soccer expert children recalled more items on the soccer list bnt not on the nonsoccer list than soccer novice children. However, soccer expertise did not modify a significant effect of IQ level, with high-IQ children recalling more than low-IQ children for all contrasts. Interest in soccer was found to be related to expertise but did not contribute to differences in memory performance. The results demonstrate that the knowledge base plays an important role in children's memory, but that domain knowledge cannot fully eliminate the effects of IQ on sort-recall tasks using domain-related materials. That is, although rich domain knowledge seemed to compensate for low aptitude, in that low-aptitude experts performed at the level of high-aptitude novices, its effects were not strong enough to eliminate performance differences between highand low-aptitude soccer experts.
High- and low-IQ children in the first, third, and fifth grades performed two free-recall tasks: a sort-recall task with sets of categorically related pictures, and a class-recall task, with children recalling the current members of their school class. All children were deemed to be experts concerning the composition of their school class, but, unlike experts in other domains, had no special motivation associated with their expertise. Recall and clustering on both tasks were high. The high-IQ children performed better than low-IQ children only on the sort-recall task. IQ was significantly correlated with measures of performance on the sort-recall task but not on the class-recall task. The results reflect the fact that the memory benefits associated with being an expert (here, elimination of IQ effects) are related to the greater knowledge the expert possesses and not to factors of motivation.