| Autism is typically characterized by impaired social cognition, and afflicted individuals often display a perturbed capacity to model others and to sense and respond appropriately to the social signals they emit (King-Casas, 2008). Before we can understand aberrant behaviors in Autism, we must first understand how the brain behaves in neurotypical controls. Functional magnetic resonance imaging (fMRI) was used to isolate a neural phenotype for social recognition during a passive picture-viewing task. I hypothesized that the cingulate cortex could discern between pictures of oneself versus another person. Twenty-seven volunteers were scanned as they viewed 15 images of themselves and 15 images of an unfamiliar person. A general linear model was used to measure brain activity, and we found significant activation in the middle cingulate cortex that on average differentiated "self" pictures from "other" pictures. This activation suggests that the cingulate is responsible for agent-discrimination and perspective taking. Significant bilateral activation in the fusiform gyrus was evoked by the presentation of both "self' and "other" images. This result is consistent with the general accepted theory that the fusiform is dedicated to face perception. Based on results by Chiu (2008) and this thesis, we have learned that the middle cingulate detects signals that distinguish "self" from "other" across three distinct social classes: pictures of faces, submitting points during a social game, and when a person imagines themselves performing an action. |
