Refine
Has Fulltext
- yes (497) (remove)
Year of publication
Document Type
- Journal article (363)
- Doctoral Thesis (111)
- Book article / Book chapter (8)
- Review (4)
- Conference Proceeding (3)
- Other (3)
- Book (2)
- Preprint (2)
- Report (1)
Language
- English (497) (remove)
Keywords
- Psychologie (56)
- EEG (20)
- virtual reality (19)
- attention (17)
- P300 (14)
- anxiety (13)
- psychology (13)
- Kognition (12)
- emotion (12)
- event-related potentials (11)
Institute
- Institut für Psychologie (497) (remove)
Sonstige beteiligte Institutionen
- Adam Opel AG (1)
- BMBF (1)
- Blindeninstitut, Ohmstr. 7, 97076, Wuerzburg, Germany (1)
- Deutsches Zentrum für Präventionsforschung Psychische Gesundheit (DZPP) (1)
- Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society (ESI) (1)
- Evangelisches Studienwerk e.V. (1)
- Forschungsverbund ForChange des Bayrischen Kultusministeriums (1)
- Klinik für Psychiatrie und Psychotherapie, Universität Würzburg (1)
- Opel Automobile GmbH (1)
- Technische Universität Dresden (1)
This article gives an overview of possibilities for the assessment offacial behavior. With regard to validity, results from a longitudinal study of 36 depressed patients and nine controls as weil as often schizophrenic patients and their relatives will be referred to. These results are used to illustrate the following principles which have to be taken into account when studying facial behavior: a) communication strongly facilitates facial expression, b) activation of facial behavior follows the "principle of least effort", and c) the principle of individual specificity applies to the association of nonverbal behavior and mood states. Making allowance for these principles has, among others, consequences a) for situations or conditions under which to asses behavior (specifically conditions of communication), b) for data analysis (e.g., dealing with frequent and rare events), and c) for empirical or experimental strategies (e.g., aggregation of single-case longitudinal comparisons). From the results on facial behavior during depression it can be concluded that the nonverbal reaction tendencies of endogenous and neurotic depressed patients differ. Moreover, the differential behavioral pattems observed cast doubt on the assumption of a homogeneity of affects in depression. Taking into account the conditions which govern it, facial behavior has proved to be a valid and, especially, a differential indicator for pathoIogic affective states and their changes. Given the fact that a psychiatric illness generally incorporates emotional problems it is more than surprising that little attention has been paid to the systematic study of emotional behavior. Some of the reasons for this will be clarified in the following.
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.
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 study investigates the sense of agency (SoA) for saccades with implicit and explicit agency measures. In two eye tracking experiments, participants moved their eyes towards on-screen stimuli that subsequently changed color. Participants then either reproduced the temporal interval between saccade and color-change (Experiment 1) or reported the time points of these events with an auditory Libet clock (Experiment 2) to measure temporal binding effects as implicit indices of SoA. Participants were either made to believe to exert control over the color change or not (agency manipulation). Explicit ratings indicated that the manipulation of causal beliefs and hence agency was successful. However, temporal binding was only evident for caused effects, and only when a sufficiently sensitive procedure was used (auditory Libet clock). This suggests a feebler connection between temporal binding and SoA than previously proposed. The results also provide evidence for a relatively fast acquisition of sense of agency for previously never experienced types of action-effect associations. This indicates that the underlying processes of action control may be rooted in more intricate and adaptable cognitive models than previously thought. Oculomotor SoA as addressed in the present study presumably represents an important cognitive foundation of gaze-based social interaction (social sense of agency) or gaze-based human-machine interaction scenarios.
Public significance statement: In this study, sense of agency for eye movements in the non-social domain is investigated in detail, using both explicit and implicit measures. Therefore, it offers novel and specific insights into comprehending sense of agency concerning effects induced by eye movements, as well as broader insights into agency pertaining to entirely newly acquired types of action-effect associations. Oculomotor sense of agency presumably represents an important cognitive foundation of gaze-based social interaction (social agency) or gaze-based human-machine interaction scenarios. Due to peculiarities of the oculomotor domain such as the varying degree of volitional control, eye movements could provide new information regarding more general theories of sense of agency in future research.
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.
Experimental investigation of the effect of distal stress induction on threat conditioning in humans
(2022)
Stress constitutes a major risk factor for the development of psychiatric disorders, such as PTSD and anxiety disorders, by shifting the brain into a state of sensitization and makes it more vulnerable when being exposed to further aversive events. This was experimentally in-vestigated in rodents by examining the effect of a distal stress induction on threat conditioning, where stress impaired extinction learning and caused spontaneous recovery. However, this effect has never been experimentally investigated in humans, so far. Thus, the aim of this dissertation was to investigate the effect of distal stress on threat conditioning in humans.
Therefore, two subsequent studies were conducted. For both studies, the threat conditioning paradigm comprised threat acquisition, extinction learning, and re-extinction. In the threat acquisition phase, two geometrical shapes were used as conditioned stimulus (CS), from which one (CS+) was paired with a painful electric stimulus (unconditioned stimulus, US), but not the other one (CS-). During extinction learning 24 h later and re-extinction seventeen days later, CSs were again presented but without any US delivery.
In Study 1, 69 participants underwent either a stress (socially evaluated cold pressor test; SECPT) or sham protocol 10 days prior to threat conditioning. Furthermore, context effects were examined by placing the stress protocol in the same context (context-A stress, and sham group) or a different context (context-B stress group) than conditioning. Results revealed that the context-A, but not context-B, stress group displayed impaired safety learning (i.e. potenti-ation towards CS-) for startle response during threat acquisition. Moreover, the same stress group showed impaired threat extinction, evident in sustained CS discrimination in valence and arousal ratings during extinction learning, and memory recall. In sum, distal stress on the one hand impaired safety learning during threat conditioning on a level of startle response. On the other hand, stress impaired threat extinction on a level of ratings. Noteworthy, the effect of distal stress was only found when the stressor was placed in the same context as later threat learning. Hence, suggesting that the combination of stressor and stressor-associated context exerted the effect on threat extinction.
In Study 2, it was examined if distal stress induction could also have an impact on threat and extinction processes without the necessity of context association. Therefore, the same stress (n = 45) or sham protocol (n = 44) as in Study 1 was conducted in a different context than and 24 h prior to a threat conditioning paradigm. Similar to Study 1, weakened extinction learning was found in fear ratings for the stress (vs. sham) group, which was indicated by persistent CS+/CS- differentiation after the first block of extinction trials. Alterations in safety learning towards the CS- during threat acquisition were only supported by significant correlations between stress measures on the stress day and conditioned startle response of the CS- during acquisition.
Taken together, in two subsequent studies this dissertation provided first evidence of impaired threat extinction after distal stress induction in humans. Furthermore, impairments in safety learning, as can be observed in PTSD, were additionally demonstrated. Interestingly, the effects were boosted and more profound when associating the stressor to the later learning context. These results have clinical implications as they can be translated to the notion that prior stress exposure makes an individual more vulnerable for later aversive events.
A hallmark of habitual actions is that, once they are established, they become insensitive to changes in the values of action outcomes. In this article, we review empirical research that examined effects of posttraining changes in outcome values in outcome-selective Pavlovian-to-instrumental transfer (PIT) tasks. This review suggests that cue-instigated action tendencies in these tasks are not affected by weak and/or incomplete revaluation procedures (e.g., selective satiety) and substantially disrupted by a strong and complete devaluation of reinforcers. In a second part, we discuss two alternative models of a motivational control of habitual action: a default-interventionist framework and expected value of control theory. It is argued that the default-interventionist framework cannot solve the problem of an infinite regress (i.e., what controls the controller?). In contrast, expected value of control can explain control of habitual actions with local computations and feedback loops without (implicit) references to control homunculi. It is argued that insensitivity to changes in action outcomes is not an intrinsic design feature of habits but, rather, a function of the cognitive system that controls habitual action tendencies.
Examining the testing effect in university teaching: retrievability and question format matter
(2018)
Review of learned material is crucial for the learning process. One approach that promises to increase the effectiveness of reviewing during learning is to answer questions about the learning content rather than restudying the material (testing effect). This effect is well established in lab experiments. However, existing research in educational contexts has often combined testing with additional didactical measures that hampers the interpretation of testing effects. We aimed to examine the testing effect in its pure form by implementing a minimal intervention design in a university lecture (N = 92). The last 10 min of each lecture session were used for reviewing the lecture content by either answering short-answer questions, multiple-choice questions, or reading summarizing statements about core lecture content. Three unannounced criterial tests measured the retention of learning content at different times (1, 12, and 23 weeks after the last lecture). A positive testing effect emerged for short-answer questions that targeted information that participants could retrieve from memory. This effect was independent of the time of test. The results indicated no testing effect for multiple-choice testing. These results suggest that short-answer testing but not multiple-choice testing may benefit learning in higher education contexts.
Background: The distinctness of grief from depression has been the subject of a long scholarly debate, even influencing definitions of diagnostic criteria. Aims: This study aims at clarifying the issue by a multifaceted analysis of data from a large German sample. Method: A community sample of 406 bereaved persons answered the Wuerzburg Grief Inventory (WGI), a multidimensional grief questionnaire designed to measure normal grief in the German language, and the General Depression Scale – Short Version (GDS-S), a self-report depression scale. Data were analyzed by factor analysis to identify structural (dis-)similarities of the constructs, and analysis of variance (ANOVA) to identify the influence of the factors relationship to the deceased, type of death, and time since loss on grief measures and depression scores. Results: Factor analysis clustered items referring to grief-related impairments and depression into one factor, items referring to other dimensions of grief on separate factors, however. Relationship to the deceased influenced the grief measures impairments and nearness to the deceased, but not depression scores if controlled for impairments. Type of death showed specific effects on grief scores, but not on depression scores. Time since loss influenced grief scores, but not depression scores. Limitations: The analysis is based on a self-selected community sample of grieving persons, self-report measures, and in part, on cross-sectional data. Conclusion: Factor analysis and objective data show a clear distinction of dimensions of grief and depression. The human experience of grief contains a sense of nearness to the lost person, feelings of guilt, and positive aspects of the loss experience in addition to components resembling depression.
It is one of the primary goals of medical care to secure good quality of life (QoL) while prolonging survival. This is a major challenge in severe medical conditions with a prognosis such as amyotrophic lateral sclerosis (ALS). Further, the definition of QoL and the question whether survival in this severe condition is compatible with a good QoL is a matter of subjective and culture-specific debate. Some people without neurodegenerative conditions believe that physical decline is incompatible with satisfactory QoL. Current data provide extensive evidence that psychosocial adaptation in ALS is possible, indicated by a satisfactory QoL. Thus, there is no fatalistic link of loss of QoL when physical health declines. There are intrinsic and extrinsic factors that have been shown to successfully facilitate and secure QoL in ALS which will be reviewed in the following article following the four ethical principles (1) Beneficence, (2) Non-maleficence, (3) Autonomy and (4) Justice, which are regarded as key elements of patient centered medical care according to Beauchamp and Childress. This is a JPND-funded work to summarize findings of the project NEEDSinALS (www.NEEDSinALS.com) which highlights subjective perspectives and preferences in medical decision making in ALS.
Background: Since the replication crisis, standardization has become even more important in psychological science and neuroscience. As a result, many methods are being reconsidered, and researchers’ degrees of freedom in these methods are being discussed as a potential source of inconsistencies across studies.
New Method: With the aim of addressing these subjectivity issues, we have been working on a tutorial-like EEG (pre-)processing pipeline to achieve an automated method based on the semi-automated analysis proposed by Delorme and Makeig.
Results: Two scripts are presented and explained step-by-step to perform basic, informed ERP and frequency-domain analyses, including data export to statistical programs and visual representations of the data. The open-source software EEGlab in MATLAB is used as the data handling platform, but scripts based on code provided by Mike Cohen (2014) are also included.
Comparison with existing methods: This accompanying tutorial-like article explains and shows how the processing of our automated pipeline affects the data and addresses, especially beginners in EEG-analysis, as other (pre)-processing chains are mostly targeting rather informed users in specialized areas or only parts of a complete procedure. In this context, we compared our pipeline with a selection of existing approaches.
Conclusion: The need for standardization and replication is evident, yet it is equally important to control the plausibility of the suggested solution by data exploration. Here, we provide the community with a tool to enhance the understanding and capability of EEG-analysis. We aim to contribute to comprehensive and reliable analyses for neuro-scientific research.
Electroencephalography (EEG) often fails to assess both the level (i.e., arousal) and the content (i.e., awareness) of pathologically altered consciousness in patients without motor responsiveness. This might be related to a decline of awareness, to episodes of low arousal and disturbed sleep patterns, and/or to distorting and attenuating effects of the skull and intermediate tissue on the recorded brain signals. Novel approaches are required to overcome these limitations. We introduced epidural electrocorticography (ECoG) for monitoring of cortical physiology in a late-stage amytrophic lateral sclerosis patient in completely locked-in state (CLIS) Despite long-term application for a period of six months, no implant related complications occurred. Recordings from the left frontal cortex were sufficient to identify three arousal states. Spectral analysis of the intrinsic oscillatory activity enabled us to extract state-dependent dominant frequencies at <4, similar to 7 and similar to 20 Hz, representing sleep-like periods, and phases of low and elevated arousal, respectively. In the absence of other biomarkers, ECoG proved to be a reliable tool for monitoring circadian rhythmicity, i.e., avoiding interference with the patient when he was sleeping and exploiting time windows of responsiveness. Moreover, the effects of interventions addressing the patient's arousal, e.g., amantadine medication, could be evaluated objectively on the basis of physiological markers, even in the absence of behavioral parameters. Epidural ECoG constitutes a feasible trade-off between surgical risk and quality of recorded brain signals to gain information on the patient's present level of arousal. This approach enables us to optimize the timing of interactions and medical interventions, all of which should take place when the patient is in a phase of high arousal. Furthermore, avoiding low responsiveness periods will facilitate measures to implement alternative communication pathways involving brain-computer interfaces (BCI).
Perceptual changes that an agent produces by efferent activity can become part of the agent’s minimal self. Yet, in human agents, efferent activities produce perceptual changes in various sensory modalities and in various temporal and spatial proximities. Some of these changes occur at the “biological” body, and they are to some extent conveyed by “private” sensory signals, whereas other changes occur in the environment of that biological body and are conveyed by “public” sensory signals. We discuss commonalties and differences of these signals for generating selfhood. We argue that despite considerable functional overlap of these sensory signals in generating self-experience, there are reasons to tell them apart in theorizing and empirical research about development of the self.
OBJECTIVE:
Somatic marker theory predicts that somatic cues serve intuitive decision making; however, cardiovascular symptoms are threat cues for patients with panic disorder (PD). Therefore, enhanced cardiac perception may aid intuitive decision making only in healthy individuals, but impair intuitive decision making in PD patients.
METHODS:
PD patients and age-and sex-matched volunteers without a psychiatric diagnosis (n=17, respectively) completed the Iowa Gambling Task (IGT) as a measure of intuitive decision making. Interindividual differences in cardiac perception were assessed with a common mental-tracking task.
RESULTS:
In line with our hypothesis, we found a pattern of opposing associations (Fisher's Z=1.78, P=0.04) of high cardiac perception with improved IGT-performance in matched control-participants (r=0.36, n=14) but impaired IGT-performance in PD patients (r=-0.38, n=13).
CONCLUSION:
Interoceptive skills, typically assumed to aid intuitive decision making, can have the opposite effect in PD patients who experience interoceptive cues as threatening, and tend to avoid them. This may explain why PD patients frequently have problems with decision making in everyday life. Screening of cardiac perception may help identifying patients who benefit from specifically tailored interventions.
Endogenous Testosterone and Exogenous Oxytocin Modulate Attentional Processing of Infant Faces
(2016)
Evidence indicates that hormones modulate the intensity of maternal care. Oxytocin is known for its positive influence on maternal behavior and its important role for childbirth. In contrast, testosterone promotes egocentric choices and reduces empathy. Further, testosterone decreases during parenthood which could be an adaptation to increased parental investment. The present study investigated the interaction between testosterone and oxytocin in attentional control and their influence on attention to baby schema in women. Higher endogenous testosterone was expected to decrease selective attention to child portraits in a face-in-the-crowd-paradigm, while oxytocin was expected to counteract this effect. As predicted, women with higher salivary testosterone were slower in orienting attention to infant targets in the context of adult distractors. Interestingly, reaction times to infant and adult stimuli decreased after oxytocin administration, but only in women with high endogenous testosterone. These results suggest that oxytocin may counteract the adverse effects of testosterone on a central aspect of social behavior and maternal caretaking.
Nurturing behavior may be critically influenced by the interplay of different hormones. The neuropeptide oxytocin is known to promote maternal behavior and its reduction has been associated with postpartum depression risk and child neglect. Contrariwise, the observed decrease in testosterone level during early parenthood may benefit caretaking behavior, whereas increased testosterone may reduce attention to infants. Here we used functional magnetic resonance imaging to investigate the interactive influence of testosterone and oxytocin on selective attention to and neural processing of the baby schema (BS). 57 nulliparous women performed a target detection task with human faces with varying degree of BS following double-blinded placebo-controlled oxytocin administration in a between-subjects design. Our results support the idea that oxytocin enhances attention to the BS. Oxytocin had a positive effect on activation of the inferior frontal junction during identification of infant targets with a high degree of BS that were presented among adult distractors. Further, activation of the putamen was positively correlated with selective attention to the BS, but only in women with high endogenous testosterone who received oxytocin. These findings provide initial evidence for the neural mechanism by which oxytocin may counteract the negative effects of testosterone in the modulation of nurturing behavior.
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.
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 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.