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Biomedical subjects

Geoffrey B C Hall

Publications and source records attributed to Geoffrey B C Hall.

3 recordsLinked to original sources

A PET provocation study of generalized social phobia.

In an investigation of the neural circuits that may mediate the subjective experience of social phobia (SP), six male patients with a primary DSM-IV diagnosis of generalized social phobia watched, in the presence of a group of "communication experts," a videotape of themselves giving an impromptu talk (Exposure condition). In the control Baseline condition, they viewed a videotape of a socially competent stranger giving a talk. Regional cerebral blood flow was measured thrice under each condition. The study revealed significant deactivations from Baseline during Exposure in the right lingual gyrus (BA 18) and in the right medial frontal gyrus (BA 11); significant activations during Exposure were not observed. Deactivation of these regions may reflect a strategy of visual avoidance employed by the patients to dampen their phobic experience.

Adolescent↗

Sex differences in functional activation patterns revealed by increased emotion processing demands.

Two [O(15)] PET studies assessed sex differences regional brain activation in the recognition of emotional stimuli. Study I revealed that the recognition of emotion in visual faces resulted in bilateral frontal activation in women, and unilateral right-sided activation in men. In study II, the complexity of the emotional face task was increased through tje addition of associated auditory emotional stimuli. Men again showed unilateral frontal activation, in this case to the left; whereas women did not show bilateral frontal activation, but showed greater limbic activity. These results suggest that when processing broader cross-modal emotional stimuli, men engage more in associative cognitive strategies while women draw more on primary emotional references.

Adult↗

Enhanced salience and emotion recognition in Autism: a PET study.

OBJECTIVE: This study examined neural activation of facial stimuli in autism when the salience of emotional cues was increased by prosodic information. METHOD: Regional cerebral blood flow (rCBF) was measured while eight high-functioning men with autism and eight men without autism performed an emotion-recognition task in which facial emotion stimuli were matched with prosodic voices and a baseline gender-recognition task. RESULTS: Emotion processing in autistic subjects, compared to that in comparison subjects, resulted in lower rCBF in the inferior frontal and fusiform areas and higher rCBF in the right anterior temporal pole, the anterior cingulate, and the thalamus. CONCLUSIONS: Even with the enhanced emotional salience of facial stimuli, adults with autism showed lower activity in the fusiform cortex and differed from the comparison subjects in activation of other brain regions. The authors suggested that the recognition of emotion by adults with autism is achieved through recruitment of brain regions concerned with allocation of attention, sensory gating, the referencing of perceptual knowledge, and categorization.

Adult↗