@phdthesis{Karl2019, author = {Karl, Christian}, title = {Kontextuelle und differentielle Einfl{\"u}sse auf die neurophysiologische Verarbeitung w{\"u}tender und neutraler Gesichter}, doi = {10.25972/OPUS-18306}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-183067}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {In dieser EEG Untersuchung wurde der Einfluss von zuvor pr{\"a}sentierten Abfolgen w{\"u}tender und neutraler Gesichtsausdr{\"u}cke auf die neurokognitive Verarbeitung eines aktuell wahrgenommenen Gesichts unter Ber{\"u}cksichtigung des modulierenden Effekts der individuellen {\"A}ngstlichkeit, sowie eines sozial stressenden Kontextes und einer erh{\"o}hten kognitiven Auslastung erforscht. Die Ergebnisse lieferten bereits auf der Ebene der basalen visuellen Gesichtsanalyse Belege f{\"u}r eine parallele Verarbeitung und Integration von strukturellen und emotionalen Gesichtsinformationen. Zudem konnte schon in dieser fr{\"u}hen Phase ein genereller kontextueller Einfluss von Gesichtssequenzen auf die kognitive Gesichtsverarbeitung nachgewiesen werden, welcher sogar in sp{\"a}teren Phasen der kognitiven Verarbeitung noch zunahm. Damit konnte nachgewiesen werden, dass die zeitliche Integration, d.h. die spezifische Abfolge wahrgenommener Gesichter eine wichtige Rolle f{\"u}r die kognitive Evaluation des aktuell perzipierten Gesichtes spielt. Diese Ergebnisse wurden zudem in einer Revision des Gesichtsverarbeitungsmodells von Haxby und Kollegen verordnet und in einer sLORETA Analyse dargestellt. Die Befunde zur individuellen {\"A}ngstlichkeit und kognitiven Auslastung best{\"a}tigten außerdem die Attentional Control Theorie und das Dual Mechanisms of Control Modell.}, subject = {Visuelle Wahrnehmung}, language = {de} } @phdthesis{Gerdes2008, author = {Gerdes, Antje B. M.}, title = {Preferential Processing of Phobic Cues : Attention and Perception in Spider Phobic Patients}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-28684}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {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.}, subject = {Phobie}, language = {en} }