This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Full Title: Amygdala activation in the processing of neutral faces in Social Anxiety Disorder Is neutral really neutral? Rationale: Social Anxiety Disorder (SAD) is a prevalent and debilitating disorder characterized by intense fear of social situations that significantly impairs quality of life. Previous research has suggested that SAD is associated with a tendency to interpret ambiguous social stimuli in a threatening manner. Recently, investigators have begun to examine the neurobiological bases of the processing of social stimuli in SAD and have found that individuals with SAD exhibit elevated activation to negative faces (specifically anger and disgust) in the anterior cingulate cortex, parahippocampal gyrus, and amygdala when their responses are contrasted with activations to neutral faces. Given the results of behavioral and imaging finding indicating that SAD individuals may perceive neutral faces as threat-related, however, it is critical to assess the neural responses of SAD individuals to neutral faces alone. The present study was designed to examine whether SAD participants exhibit activation to neutral faces in areas of the brain that have been found to be associated with the processing of negative faces. We hypothesized that, compared with nonpsychiatric controls, individuals diagnosed with SAD would exhibit increased amygdala activation in response to neutral faces versus an oval fixation. Methods: Ten participants with SAD and ten healthy control participants (CTL) viewed neutral faces from 20 actors and an oval with a cross-hair in the middle in the scanner in an event-related design. Participants were instructed to use a button box to make valence ratings (negative, neutral, or positive) and to indicate neutral when they saw an oval. Results: Analyses of activations in bilateral amygdala ROIs for the neutral face vs. oval contrasts revealed that whereas SAD participants demonstrated significantly greater activation in the right amygdala [Tal., 19,-7,-19] than did controls (z=2.80, P=0.005), CTL participants exhibited significantly greater activation in the left amygdala [Tal., -19,-3,-17] than did SAD participants (z=-2.98, P=0.003). Importantly, the SAD and CTL groups did not differ significantly in the time course to ovals, suggesting that the group differences in amygdala activations in the neutral face vs. ovals contrasts are not driven by increased activation to ovals in the SAD group.
Showing the most recent 10 out of 446 publications
