<p>We were interested in localizing the regionally specific brain responses which underlie the emotion processing strategies of men, women and a clinical population of individuals with emotion processing deficits: autism. In two studies we identified the brain regions involved in the recognition of emotion by measuring changes in regional cerebral blood flow (rCBF) using positron tomography. Study I asked adult men and women to perform face detection, identity matching and emotion matching tasks and compared the distribution of rCBF produced by each task. The recognition of facial emotion by males was associated with activation of the right inferior frontal cortex, whereas in females, activation of the frontal cortices bilaterally, and the right middle temporal and right inferior occipital gyri was identified. Between-group comparisons of the activations associated with facial emotion processing revealed that males showed greater right sided activation of medial frontal and superior occipital regions and less activation of the left inferior frontal gyrus, left fusiform gyrus and right amygdala than did women. Localization of function to these regions is consistent with other research results identifying greater distribution and less lateralization of cognitive functions in females than males. In our second study we presented cross-modal (auditory-visual) gender matching and emotion matching tasks to three groups of adults; men, women, and high functioning men with autism. Compared to the gender matching task, emotion matching was associated with activation of a left inferior frontal region in males, and the right superior temporal gyrus and right anterior cingulate gyrus in females. This pattern was similarly reflected in between-group comparisons, which identified significantly greater activations in a left inferior frontal region for males, and greater anterior cingulate and fusiform activations for females. These results identify sex differences in cross-modal emotion processing. Localization to these regions suggests that females placed greater relative processing emphasis on the auditory-prosodic and motivational qualities of the current experience, whereas males relied more on processes engaged in the construction of an integrated emotional experience and the regulation of responses. Cross-modal emotion matching by adults with autism was associated with activation of Broca's region, and bilateral anterior temporal poles. Between-group comparisons identified significantly greater activation of the right anterior temporal pole and anterior cingulate by the adults with autism, as compared to controls. These findings suggest that the adults with autism placed greater emphasis on processes involved in accessing perceptual knowledge to guide the categorization of emotional stimuli, verbal problem solving, directing attention toward cross-modal information sources and/or assessing the motivational content of stimuli.</p> / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/7057 |
| Date | January 2001 |
| Creators | Hall, Brian Charles Geoffrey |
| Contributors | Nahmias, Claude, Medical Sciences |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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