Automatic and controlled processing of faces in social anxiety
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The aim of this dissertation was to investigate the automatic emotional response, attention allocation, and attention disengagement elicited by facial stimuli in undergraduate participants with high and low Social Anxiety (SA). Affective faces (happy, neutral, angry) were subliminally presented to participants in two phases. During the first phase, Prepulse Inhibition of Startle (PPI) was used as an index of attention allocation and attention disengagement in response to the subliminally presented affective faces. During the second phase, a subset of the participants from the first phase viewed the same faces during Functional Magnetic Resonance Imaging (fMRI). Activation in the amygdala was examined as an index of automatic emotional response. PPI and fMRI were compared across face expression and gender for participants with high and low SA. PPI results revealed that by 300 ms, more attention was allocated to subliminally presented angry faces compared to neutral faces in all participants. All participants then subsequently disengaged attention from the faces by 800 ms. fMRI results revealed that amygdala activation did not differ across face conditions or SA groups, but other brain areas, including the anterior cingulate cortex, were modulated by facial expression differently across SA groups. In addition, correlations were computed between measures. Finally, fMRI, PPI, and self-report data underwent Hierarchical Linear Modeling to investigate relationships between automatic emotional response, attention allocation, and attention disengagement in participants with high and low SA. Relationships between these measures were not supported, suggesting that they may be independent constructs. Limitations and future directions are discussed.
Table of Contents
Overview -- Literature review -- Method -- Results -- Discussion -- Appendices