EMOTIONAL AROUSAL AND ACTIVATION OF THE VISUAL-CORTEX - AN FMRI ANALYSIS

Functional activity in the visual cortex was assessed using functional magnetic resonance imaging technology while participants viewed a ser ies of pleasant, neutral, or unpleasant pictures. Coronal images at fo ur different locations in the occipital cortex were acquired during ea ch of eight 12-s picture presentation periods (on) and 12-s interpictu re interval (off). The extent of functional activation was larger in t he right than the left hemisphere and larger in the occipital than in the occipitoparietal regions during processing of all picture contents compared with the interpicture intervals. More importantly, functiona l activity was significantly greater in all sampled brain regions when processing emotional (pleasant or unpleasant) pictures than when proc essing neutral stimuli. In Experiment 2, a hypothesis that these diffe rences were an artifact of differential eye movements was ruled out. W hereas both emotional and neutral pictures produced activity centered on the calcarine fissure (Area 17), only emotional pictures also produ ced sizable clusters bilaterally in the occipital gyrus, in the right fusiform gyrus, and in the right inferior and superior parietal lobule s.