Date of Award
Doctor of Philosophy (PhD)
Louis A. Schmidt
Social fears gain in prominence among higher primates, including humans, where threats associated with other conspecifics become more common. Social fearfulness is expressed on a continuum, ranging from shyness to a diagnosable psychiatric disorder. Despite the wide prevalence and considerable distress associated with social anxiety, our understanding of its neural and cognitive correlates remains in its infancy and remains an imperative for future translational research. The current dissertation examined social anxiety by utilizing multiple experimental approaches and employing a broad range of measures involving neural, cognitive, behavioural and clinical assessments.
Chapters 2 to 4 relied on nonclinical samples of adults selected for social anxiety from a large adult population. Chapters 2 and 3 employed event-related brain potentials to index distinct aspects of perceptual and cognitive processing in tasks that manipulated novelty under socio-emotional and affectively neutral contexts. The aim was to provide a fine-grained characterization of the information processing stages that are biased by social anxiety. Chapter 4 measured reaction times in a selective attention task that independently varied the temporal and energetic aspects of affective stimulus delivery to provide convergent evidence into how affective processing is perturbed by social anxiety. Chapter 5 employed a novel method of quantifying continuous EEG to examine large-scale brain activity during rest and symptom provocation in patients diagnosed with social anxiety disorder. The aim was to examine, for the first time, whether there are treatment-related changes in a measure that putatively indexes communication across different (cortical and subcortical) neuronal systems.
Findings suggest that social anxiety is associated with a sensitization of (bottom-up) systems reacting to social threat and that these biases appear during the early, relatively automatic stages of information processing. Some of these systems may be susceptible to evidence-based psychological treatments that are correlated with changes in brain activity detectable in EEG patterns.
Miskovic, Vladimir, "The Psychophysiology of Social Anxiety: An Integrative Perspective" (2011). Open Access Dissertations and Theses. Paper 4901.
McMaster University Library