TY - THES A1 - Murali, Supriya T1 - Understanding the function of spontaneous blinks by investigating internally and externally directed processes T1 - Eine Untersuchung zur Funktion spontaner Lidschläge durch die Differenzierung von extern und intern gerichteten Prozessen N2 - Humans spontaneously blink several times a minute. These blinks are strongly modulated during various cognitive task. However, the precise function of blinking and the reason for their modulation has not been fully understood. In the present work, I investigated the function of spontaneous blinks through various perceptual and cognitive tasks. Previous research has revealed that blinks rates decrease during some tasks but increase during others. When trying to understand these seemingly contradictory results, I observed that blink reduction occurs when one engages with an external input. For instance, a decrease has been observed due to the onset of a stimulus, sensory input processing and attention towards sensory input. However, for activities that do not involve such an engagement, e.g. imagination, daydreaming or creativity, the blink rate has been shown to increase. To follow up on the proposed hypothesis, I distinguished tasks that involve the processing of an external stimulus and tasks that involve disengagement. In the first part of the project, I explored blinking during stimulus engagement. If the probability of blinking is low when engaging with the stimulus, then one should find a reduction in blinks specifically during the time period of processing but not during sensory input per se. To this end, in study 1, I tested the influence of task-relevant information duration on blink timing and additionally manipulated the overall sensory input using a visual and an auditory temporal simultaneity judgement task. The results showed that blinks were suppressed longer for longer periods of relevant information or in other words, blinks occurred at the end of relevant information processing for both the visual and the auditory modality. Since relevance is mediated through top-down processes, I argue that the reduction in blinks is a top-down driven suppression. In studies 2 and 3, I again investigated stimulus processing, but in this case, processing was triggered internally and not based on specific changes in the external input. To this end, I used bistable stimuli, in which the actual physical stimulus remains constant but their perception switches between different interpretations. Studies on the involvement of attention in such bistable perceptual changes indicate that the sensory input is reprocessed before the perceptual switch. The results revealed a reduction in eye blink rates before the report of perceptual switches. Importantly, I was able to decipher that the decrease was not caused by the perceptual switch or the behavioral response but likely started before the internal switch. Additionally, periods between a blink and a switch were longer than interblink intervals, indicating that blinks were followed by a period of stable percept. To conclude, the first part of the project revealed that there is a top-down driven blink suppression during the processing of an external stimulus. In the second part of the project, I extended the idea of blinks marking the disengagement from external processing and tested if blinking is associated with better performance during internally directed processes. Specifically, I investigated divergent thinking, an aspect of creativity, and the link between performance and blink rates as well as the effect of motor restriction. While I could show that motor restriction was the main factor influencing divergent thinking, the relationship between eye blink rates and creative output also depended on restriction. Results showed that higher blink rates were associated with better performance during free movement, but only between subjects. In other words, subjects who had overall higher blink rates scored better in the task, but when they were allowed to sit or walk freely. Within a single subject, trial with higher blink rates were not associated with better performance. Therefore, possibly, people who are able to disengage easily, as indicated by an overall high blink rate, perform better in divergent thinking tasks. However, the link between blink rate and internal tasks is not clear at this point. Indeed, a more complex measurement of blink behavior might be necessary to understand the relationship. In the final part of the project, I aimed to further understand the function of blinks through their neural correlates. I extracted the blink-related neural activity in the primary visual cortex (V1) of existing recordings of three rhesus monkeys during different sensory processing states. I analyzed spike related multi-unit responses, frequency dependent power changes, local field potentials and laminar distribution of activity while the animal watched a movie compared to when it was shown a blank screen. The results showed a difference in blink-related neural activity dependent on the processing state. This difference suggests a state dependent function of blinks. Taken altogether, the work presented in this thesis suggests that eye blinks have an important function during cognitive and perceptual processes. Blinks seem to facilitate a disengagement from the external world and are therefore suppressed during intended processing of external stimuli. N2 - Menschen blinzeln spontan mehrmals pro Minute. Während verschiedener kognitiver Aufgaben ist die Häufigkeit dieser Lidschläge sehr unterschiedlich. Jedoch ist die genaue Funktion des spontanen Lidschlags und der Grund für deren Modulation noch nicht vollständig verstanden. In der vorliegenden Arbeit habe ich die Funktion des spontanen Lidschlags durch verschiedene Aufgaben im Bereich der Wahrnehmung und Kognition untersucht. Frühere Studien haben gezeigt, dass die Häufigkeit der Lidschläge bei einigen Aufgaben abnimmt, bei anderen jedoch zunimmt. Bei der Prüfung dieser scheinbar widersprüchlichen Ergebnisse beobachtete ich, dass die Reduzierung der Lidschlaghäufigkeit scheinbar immer bei der Beschäftigung mit externem Input auftritt. Zum Beispiel wurde eine Abnahme aufgrund des Beginns eines sensorischen Reizes, der Verarbeitung sensorischen Inputs und von Aufmerksamkeit auf sensorischen Input beschrieben. Für Aktivitäten ohne solch externes Engagement, z.B. Fantasie, Tagträume oder Kreativität, nimmt die Häufigkeit der Lidschläge zu. Um die vorgeschlagene Hypothese zu überprüfen, untersuchte ich explizit solche Aufgaben mit Verarbeitung eines externen Reizes und solchen mit einer Abgrenzung von externem Input. Im ersten Teil des Projekts untersuchte ich die Lidschläge während der Präsentation von externen Reizen. Falls die Wahrscheinlichkeit der Lidschläge an eine Reizverarbeitung gekoppelt ist, sollte man eine Verringerung der Lidschläge während des Verarbeitungszeitraums feststellen aber nicht während sensorischen Inputs an sich. Zu diesem Zweck habe ich in Studie 1 den Einfluss der aufgabenrelevanten Informationsdauer unabhängig vom gesamten sensorischen Input auf den Zeitpunkt des Lidschlags getestet. Dies geschah mit einer visuellen und einer auditiven Aufgabe zur zeitlichen Gleichzeitigkeitsbeurteilung. Die Ergebnisse zeigten, dass Lidschläge während Zeitfenster mit relevanten Informationen unterdrückt wurden, oder anders gesagt, Lidschläge traten am Ende der Informationsverarbeitung sowohl in der visuellen als auch auditorischen Modalität auf. Weil Relevanz durch Top-Down-Prozesse vermittelt wird, behaupte ich, dass die Verringerung der Lidschläge eine Top-Down-gesteuerte Unterdrückung ist. In den Studien 2 und 3 habe ich die Reizverarbeitung erneut untersucht, aber jetzt wurde die Verarbeitung intern ausgelöst und nicht auf Basis von spezifischen Änderungen im externen Input. Dazu habe ich bistabile Reize verwendet, bei denen der physikalische Reiz selber konstant bleibt, aber die Wahrnehmung zwischen verschiedenen Interpretationen wechselt. Studien über die Rolle der Aufmerksamkeit bei bistabilen Wahrnehmungsveränderungen zeigen, dass der sensorische Input vor dem Wahrnehmungswechsel erneut verarbeitet wird. Die Ergebnisse deckten eine Verringerung in der Häufigkeit der Lidschläge vor der Mitteilung über Wahrnehmungswechsel auf. Eine wichtige Erkenntnis hierbei war, dass diese Verringerung nicht durch den Wahrnehmungswechsel oder die Verhaltensreaktion verursacht wurde, sondern mit großer Wahrscheinlichkeit schon vor dem internen Wechsel anfing. Außerdem waren die Perioden zwischen einem Lidschlag und einem Wahrnehmungswechsel länger als die Intervalle zwischen den Lidschlägen, was darauf hinweist, dass einem Lidschlag eine Zeit stabiler Wahrnehmung folgt. Zusammenfassend zeigte der erste Teil des Projekts die Existenz einer Top-Down-gesteuerten Lidschlag-Unterdrückung während der Verarbeitung eines externen Stimulus. Die Idee dass Lidschläge eine Abgrenzung von der Verarbeitung externer Signale markieren habe ich im zweiten Teil des Projekts erweitert und getestet, ob blinzeln mit einer besseren Leistung während intern gesteuerter Prozesse verbunden ist. Insbesondere untersuchte ich divergentes Denken, ein Aspekt der Kreativität, und den Zusammenhang zwischen kreativer Leistung und Häufigkeit der Lidschläge sowie die Wirkung von motorischer Einschränkung. Ich konnte den Einfluss von motorischer Einschränkung auf divergentes Denken aufzeigen, jedoch auch dass die Beziehung zwischen Häufigkeit der Lidschläge und kreativem Output von der motorischen Einschränkung abhängig ist. Die Ergebnisse zeigten eine Verbindung zwischen höherer Lidschlaghäufigkeit und besseren Leistung bei freier Bewegung, jedoch nur innerhalb der Gruppe. Anders gesagt, Probanden mit insgesamt höherer Häufigkeit der Lidschläge erzielten bei der Aufgabe besser Resultate, aber nur wenn sie sich frei bewegen durften. Innerhalb eines Probanden waren Versuche mit höherer Häufigkeit der Lidschläge nicht mit einer besseren Leistung verbunden. Eine mögliche Interpretation ist, dass Menschen die sich insgesamt leichter von sensorischem Input abgrenzen, was möglicherweise durch eine insgesamt hohe Häufigkeit der Lidschläge angezeigt wird, bei divergenten Denkaufgaben besser abschneiden. Allerdings ist der Zusammenhang zwischen Häufigkeit der Lidschläge und internen Aufgaben an dieser Stelle noch nicht klar. Tatsächlich könnte eine komplexere Messung des Lidschlagverhaltens notwendig sein, um die Beziehung zu verstehen. Im letzten Teil des Projekts wollte ich die Funktion von Lidschlägen über ihre neuronalen Korrelate besser verstehen. Ich habe die lidschlagbezogene neuronale Aktivität im primären visuellen Kortex (V1) aus bestehenden Aufzeichnungen von drei Rhesusaffen bei verschiedenen Aufmerksamkeitsverarbeitungszuständen extrahiert. Die lidschlagbezogene Rate der Aktionspotentiale, die Multi-Unit-Aktivität, frequenzabhängige Aktivität, lokale Feldpotentiale und laminare Aktivitätsverteilung habe ich während zwei Versuchsbedingungen analysiert, das Anschauen eines Films und einer Pause vor einem leeren Bildschirm. Die Ergebnisse zeigten einen Unterschied in der lidschlagbezogenen neuronalen Aktivität in Abhängigkeit von der Versuchsbedingung und somit dem Verarbeitungszustand. Dieser Unterschied deutet eine zustandsabhängige Funktion der Lidschläge an. Insgesamt legt die in dieser Dissertation vorgestellte Arbeit nahe, dass Lidschläge eine wichtige Funktion in Kognition und Wahrnehmungsprozessen hat. Lidschläge scheinen eine Abgrenzung von der Außenwelt zu erleichtern und werden daher bei beabsichtigter Verarbeitung externer Reize unterdrückt. KW - Lidschlag KW - Kognition KW - Aufmerksamkeit KW - Wahrnehmung KW - spontaneous blinks KW - attention KW - perception Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287473 ER - TY - JOUR A1 - Diemer, Julia A1 - Alpers, Georg W. A1 - Peperkorn, Henrik M. A1 - Shiban, Youssef A1 - Mühlberger, Andreas T1 - The impact of perception and presence on emotional reactions: a review of research in virtual reality JF - Frontiers in Psychology N2 - Virtual reality (VR) has made its way into mainstream psychological research in the last two decades. This technology, with its unique ability to simulate complex, real situations and contexts, offers researchers unprecedented opportunities to investigate human behavior in well controlled designs in the laboratory. One important application of VR is the investigation of pathological processes in mental disorders, especially anxiety disorders. Research on the processes underlying threat perception, fear, and exposure therapy has shed light on more general aspects of the relation between perception and emotion. Being by its nature virtual, i.e., simulation of reality, VR strongly relies on the adequate selection of specific perceptual cues to activate emotions. Emotional experiences in turn are related to presence, another important concept in VR, which describes the user's sense of being in a VR environment. This paper summarizes current research into perception of fear cues, emotion, and presence, aiming at the identification of the most relevant aspects of emotional experience in VR and their mutual relations. A special focus lies on a series of recent experiments designed to test the relative contribution of perception and conceptual information on fear in VR. This strand of research capitalizes on the dissociation between perception (bottom up input) and conceptual information (top-down input) that is possible in VR. Further, we review the factors that have so far been recognized to influence presence, with emotions (e.g., fear) being the most relevant in the context of clinical psychology. Recent research has highlighted the mutual influence of presence and fear in VR, but has also traced the limits of our current understanding of this relationship. In this paper, the crucial role of perception on eliciting emotional reactions is highlighted, and the role of arousal as a basic dimension of emotional experience is discussed. An interoceptive attribution model of presence is suggested as a first step toward an integrative framework for emotion research in VR. Gaps in the current literature and future directions are outlined. KW - exposure therapy KW - flight phobics KW - environments KW - virtual reality KW - anxiety KW - presence KW - emotion KW - fear KW - perception KW - anxiety disorders KW - presence questionnaire KW - public speaking KW - spider phobia KW - social phobia KW - immersion Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144200 VL - 6 IS - 26 ER - TY - JOUR A1 - Fischer, Rico A1 - Plessow, Franziska A1 - Kiesel, Andrea T1 - The effects of alerting signals in masked priming JF - Frontiers in Psychology N2 - 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. KW - response selection KW - visual cortex KW - temporal predictability KW - stimuli KW - primes KW - target primes KW - simon task KW - automaticity KW - performance KW - perception KW - mechanism KW - novel primes KW - action-trigger KW - masked priming KW - accessory KW - alerting signal Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122581 SN - 1664-1078 VL - 4 IS - 448 ER - TY - JOUR A1 - Peperkorn, Henrik M. A1 - Diemer, Julia E. A1 - Alpers, Georg W. A1 - Mühlberger, Andreas T1 - Representation of Patients' Hand Modulates Fear Reactions of Patients with Spider Phobia in Virtual Reality JF - frontiers in Psychology N2 - Embodiment (i.e., the involvement of a bodily representation) is thought to be relevant in emotional experiences. Virtual reality (VR) is a capable means of activating phobic fear in patients. The representation of the patient’s body (e.g., the right hand) in VR enhances immersion and increases presence, but its effect on phobic fear is still unknown. We analyzed the influence of the presentation of the participant’s hand in VR on presence and fear responses in 32 women with spider phobia and 32 matched controls. Participants sat in front of a table with an acrylic glass container within reaching distance. During the experiment this setup was concealed by a head-mounted display (HMD). The VR scenario presented via HMD showed the same setup, i.e., a table with an acrylic glass container. Participants were randomly assigned to one of two experimental groups. In one group, fear responses were triggered by fear-relevant visual input in VR (virtual spider in the virtual acrylic glass container), while information about a real but unseen neutral control animal (living snake in the acrylic glass container) was given. The second group received fear-relevant information of the real but unseen situation (living spider in the acrylic glass container), but visual input was kept neutral VR (virtual snake in the virtual acrylic glass container). Participants were instructed to touch the acrylic glass container with their right hand in 20 consecutive trials. Visibility of the hand was varied randomly in a within-subjects design. We found for all participants that visibility of the participant’s hand increased presence independently of the fear trigger. However, in patients, the influence of the virtual hand on fear depended on the fear trigger. When fear was triggered perceptually, i.e., by a virtual spider, the virtual hand increased fear. When fear was triggered by information about a real spider, the virtual hand had no effect on fear. Our results shed light on the significance of different fear triggers (visual, conceptual) in interaction with body representations. KW - virtual reality KW - presence KW - immersion KW - perception KW - fear KW - specific phobia Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165307 VL - 7 IS - 268 ER - TY - THES A1 - Gerdes, Antje B. M. T1 - Preferential Processing of Phobic Cues : Attention and Perception in Spider Phobic Patients T1 - Bevorzugte Verarbeitung phobischer Reize : Aufmerksamkeits- und Wahrnehmungsprozesse bei spinnenphobischen Patienten N2 - 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. N2 - Kognitive Theorien nehmen an, dass Aufmerksamkeitsverzerrungen bezüglich bedrohlicher Reize eine substantielle Rolle bei der Entstehung und Aufrechterhaltung von Angst spielen. Für gesunde Personen konnte gezeigt werden, dass bedrohliche Reize die Aufmerksamkeit auf sich ziehen und verstärkt im visuellen System verarbeitet werden. Es wird angenommen, dass diese bevorzugten Verarbeitungsprozesse automatisch und präattentiv sind und von einer schnellen Aufmerksamkeitsausrichtung gefolgt werden. Hochängstliche Personen zeigen eine verstärkte Tendenz, ihre Aufmerksamkeit selektiv auf Gefahrenreize auszurichten (Mathews, 1990) und verarbeiten diese Reize auch auf neuronaler Ebene intensiver als nichtängstliche Personen (Dilger, et al., 2003). Bisher ungeklärt ist, ob bedrohliche Reize tatsächlich die Aufmerksamkeit initial auf sich ziehen oder ob die beschriebenen Aufmerksamkeitsverzerrungen besserdurch Schwierigkeiten, Aufmerksamkeit von Gefahrenreizen abzuwenden, erklärt werden können. Darüberhinaus wurde bisher kaum untersucht, ob sich eine bevorzugte Verarbeitung von angstrelevanten Reizen auch auf die Wahrnehmung ängstlicher Personen auswirken kann. Um verschiedene Aufmerksamkeitskomponenten direkt zu untersuchen, wurden in der ersten Studie dieser Dissertation sowohl manuelle Reaktionszeiten als auch Augenbewegungen erfasst. 21 Patienten mit Spinnenphobie und 21 nichtängstliche Kontrollpersonen sollten während der Suche nach einem neutralen Zielreiz aufgabenirrelevante kreisförmige Reize explizit ignorieren, die kleine Bilder von Spinnen (phobisch), Blumen (nicht phobisch, aber mit spinnenähnlicher Form), Pilzen (nicht phobisch und keine spinnenähnliche Form) oder kein Bild enthalten konnten. Wie erwartet zeigte sich, dass die Reaktionszeiten der Patienten in den Durchgängen langsamer waren, in denen aufgabenirrelevante Spinnen auftauchten. Allerdings zeigte die Analyse der Augenbewegungen, dass die Spinnen initial nicht häufiger fixiert wurden, sondern die Patienten häufiger auf alle Distraktoren mit Bild schauten. Allerdings verweilte der Blick der Patienten länger auf den Spinnenbildern, was die verlangsamten Reaktionen auf den Zielreiz erklären kann. Diese Befunde unterstützen nicht die Annahme einer automatischen Entdeckung phobischer Reize, sondern weisen vielmehr auf Schwierigkeiten phobischer Patienten hin, die Aufmerksamkeit von Spinnen zu lösen. In der zweiten Studie dieser Dissertation wurde ein binokulares Rivalitätsparadigma eingesetzt, um zu untersuchen, ob eine bevorzugte Verarbeitung phobischer Reize die visuelle Wahrnehmung bei Patienten mit Spinnenphobie beeinflussen kann. Bei diesem Paradigma wird jedem Auge ein unterschiedliches Bild dargeboten, was zu einem Wahrnehmungswechsel führt, bei dem jeweils ein Bild die bewusste Wahrnehmung dominiert während das andere unterdrückt wird. 23 Patienten mit Spinnenphobie und 20 nichtängstlichen Kontrollpersonen wurden standardisierte Bilder von Spinnen und Blumen, jeweils gepaart mit einem neutralen Muster, stereoskopisch dargeboten. Die Aufgabe bestand darin, durchgehend die dominante Wahrnehmung durch Tastendruck zu kodieren. Patienten mit Spinnenphobie berichteten häufiger und länger, Spinnenbilder dominant wahrzunehmen. Diese Wahrnehmungsdominanz von phobischen Reizen bei binokularer Rivalität weist darauf hin, dass eine bevorzugte Verarbeitung bedrohlicher Reize im visuellen System dazu führen kann, dass diese Reize auch verstärkt wahrgenommen werden. Zusammenfassend unterstützen die Befunde beider Studien die Annahme, dass Patienten mit Spinnenphobie phobierelevante Reize innerhalb des visuellen Systems bevorzugt verarbeiten, was sich in verzögerter Aufmerksamkeitsabwendung zeigt und des Weiteren zu einer verstärkten Wahrnehmung der bedrohlichen Reizen führt. KW - Phobie KW - Visuelle Aufmerksamkeit KW - Visuelle Wahrnehmung KW - Angst KW - Disengagement KW - Spinnenphobie KW - Aufmerksamkeitsprozesse KW - Engagement KW - Disengagement KW - Binokulare Rivalität KW - spider phobia KW - attention KW - perception KW - engagement KW - disengagement KW - binocular rivalry Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-28684 ER - TY - JOUR A1 - Gruss, L. Forest A1 - Wieser, Matthias J. A1 - Schweinberger, Stefan R. A1 - Keil, Andreas T1 - Face-evoked steady-state visual potentials: effects of presentation rate and face inversion JF - Frontiers in Human Neuroscience N2 - 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. KW - N170 KW - upside-down faces KW - selective attention KW - spatial attention KW - cortex KW - perception KW - recognition KW - brain KW - FMRI KW - area Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134399 VL - 6 IS - 316 ER - TY - JOUR A1 - Kozlik, Julia A1 - Neumann, Roland A1 - Lozo, Ljubica T1 - Contrasting motivational orientation and evaluative coding accounts: on the need to differentiate the effectors of approach/avoidance responses JF - Frontiers in Psychology N2 - Several emotion theorists suggest that valenced stimuli automatically trigger motivational orientations and thereby facilitate corresponding behavior. Positive stimuli were thought to activate approach motivational circuits which in turn primed approach-related behavioral tendencies whereas negative stimuli were supposed to activate avoidance motivational circuits so that avoidance-related behavioral tendencies were primed (motivational orientation account). However, recent research suggests that typically observed affective stimulus response compatibility phenomena might be entirely explained in terms of theories accounting for mechanisms of general action control instead of assuming motivational orientations to mediate the effects (evaluative coding account). In what follows, we explore to what extent this notion is applicable. We present literature suggesting that evaluative coding mechanisms indeed influence a wide variety of affective stimulus response compatibility phenomena. However, the evaluative coding account does not seem to be sufficient to explain affective S-R compatibility effects. Instead, several studies provide clear evidence in favor of the motivational orientation account that seems to operate independently of evaluative coding mechanisms. Implications for theoretical developments and future research designs are discussed. KW - emotional facial expressions KW - cerebral asymmetry KW - compatibility KW - perception KW - affective S-R compatibility KW - approach-avoidance behavior KW - automatic evaluation KW - arm flexion KW - stimuli KW - determinants KW - information KW - emotional responses KW - approach and avoidance KW - facial muscle contractions KW - theory of event coding Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143192 VL - 6 IS - 563 ER - TY - JOUR A1 - Kirsch, Wladimir A1 - Kunde, Wilfried T1 - Changes in body perception following virtual object manipulation are accompanied by changes of the internal reference scale JF - Scientific Reports N2 - Changes in body perception often arise when observers are confronted with related yet discrepant multisensory signals. Some of these effects are interpreted as outcomes of sensory integration of various signals, whereas related biases are ascribed to learning-dependent recalibration of coding individual signals. The present study explored whether the same sensorimotor experience entails changes in body perception that are indicative of multisensory integration and those that indicate recalibration. Participants enclosed visual objects by a pair of visual cursors controlled by finger movements. Then either they judged their perceived finger posture (indicating multisensory integration) or they produced a certain finger posture (indicating recalibration). An experimental variation of the size of the visual object resulted in systematic and opposite biases of the perceived and produced finger distances. This pattern of results is consistent with the assumption that multisensory integration and recalibration had a common origin in the task we used. KW - human behaviour KW - perception Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357876 VL - 13 ER - TY - JOUR A1 - Kirsch, Wladimir A1 - Ullrich, Benjamin A1 - Kunde, Wilfried T1 - Are Effects of Action on Perception Real? Evidence from Transformed Movements JF - PLoS ONE N2 - It has been argued that several reported non-visual influences on perception cannot be truly perceptual. If they were, they should affect the perception of target objects and reference objects used to express perceptual judgments, and thus cancel each other out. This reasoning presumes that non-visual manipulations impact target objects and comparison objects equally. In the present study we show that equalizing a body-related manipulation between target objects and reference objects essentially abolishes the impact of that manipulation so as it should do when that manipulation actually altered perception. Moreover, the manipulation has an impact on judgements when applied to only the target object but not to the reference object, and that impact reverses when only applied to the reference object but not to the target object. A perceptual explanation predicts this reversal, whereas explanations in terms of post-perceptual response biases or demand effects do not. Altogether these results suggest that body-related influences on perception cannot as a whole be attributed to extra-perceptual factors. KW - vision KW - preprocessing KW - analysis of variance KW - sensory perception KW - hands KW - fingers KW - experimental design KW - perception Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178574 VL - 11 IS - 12 ER - TY - JOUR A1 - Kirsch, Wladimir A1 - Kitzmann, Tim A1 - Kunde, Wilfried T1 - Action affects perception through modulation of attention JF - Attention, Perception & Psychophysics N2 - The present study explored the origin of perceptual changes repeatedly observed in the context of actions. In Experiment 1, participants tried to hit a circular target with a stylus movement under restricted feedback conditions. We measured the perception of target size during action planning and observed larger estimates for larger movement distances. In Experiment 2, we then tested the hypothesis that this action specific influence on perception is due to changes in the allocation of spatial attention. For this purpose, we replaced the hitting task by conditions of focused and distributed attention and measured the perception of the former target stimulus. The results revealed changes in the perceived stimulus size very similar to those observed in Experiment 1. These results indicate that action's effects on perception root in changes of spatial attention. KW - perception KW - action KW - attention Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-273176 SN - 1943-393X VL - 83 IS - 5 ER -