BRAIN-REGIONS INVOLVED IN THE PERCEPTION OF GAZE - A PET STUDY

Mutual gaze may be described as a psychological process during which t wo persons have the feeling of a brief link between their two minds. I n the monkey, specific cell assemblies in the superior temporal cortex of the brain are responsive to gaze. This suggests that the brain may have evolved mechanisms for interpreting direct eye contact. These me chanisms could depend on the activation of specific brain regions. Pos itron emission tomography was used to measure activity in brain region s in healthy volunteers while they were looking at faces featuring, re spectively, eye contact, averted gaze, or no gaze. As expected a regio n known to be involved in face processing was found to be activated in the ventral occipito-temporal region, especially in the right hemisph ere. Averted gaze and mutual gaze triggered blood flow responses in si milar areas which were different from those involved in face processin g. These areas included the occipital part of the fusiform gyrus, the right parietal lobule, the right inferior temporal gyrus, and the midd le temporal gyrus in both hemispheres. These results are consistent wi th the hypothesis that perception of eyes regardless of the direction of the gaze is subserved by a distributed network. However, no conclus ive evidence was found for specific area(s) devoted to mutual gaze pro cessing, (C) 1998 Academic Press.