Dissociating Inherent Emotional and Associated Motivational Salience in Human Face Processing
by Wiebke Hammerschmidt
Date of Examination:2018-04-11
Date of issue:2018-05-30
Advisor:Prof. Dr. Annekathrin Schacht
Referee:Prof. Dr. Annekathrin Schacht
Referee:Dr. Igor Kagan
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Abstract
English
The human brain is challenged to select only the most relevant stimuli, assured by salienceand goal-driven attention mechanisms. As not only stimuli carrying inherent salience (e.g., facial expressions of emotion), but also learned stimulus-reward associations were shown to elicit attentional prioritization, an additional value-driven attention mechanism (B. A. Anderson, 2013) was suggested. A direct comparison, however, was absent. Therefore, the aim of the present PhD project was to fill this gap in the literature by investigating the dissociation of neural impacts of associated motivational and inherent emotional salience on human face processing. Three studies, measuring event-related brain potentials (ERPs), were conducted to examine the potential processing advantage of neutral expressions previously associated with motivational salience via explicit (Study 1 ) and implicit (Study 2 ) associative learning. In addition, ERP modulations elicited by associated motivational salience were compared to those evoked by facial expressions of emotion. Study 3 aimed to assess the integration of inherent emotional and associative motivational salience. The results demonstrated that inherently neutral stimuli can acquire increased salience via associative learning and might impact initial perceptual (Study 1 ) or elaborative processing stages (Study 2 and 3 ). The sensory encoding, however, was limited to biologically determined sources of emotional salience (Study 1 to 3 ) as provided by facial expressions of emotion. In summary, the findings confirmed that emotionally and motivationally relevant stimuli elicit a comparable attentional prioritization, as proposed by the value-driven attention mechanism. Associated motivational salience, however, does not seem to trigger an inherent emotional meaning.
Keywords: Event-related brain potentials (ERPs); Motivational salience; Emotional expressions; Associative learning