Analysis of evoked EEG synchronization and desynchronization during perception of emotiogenic stimuli: association with autonomic activation processes.

The cortical apparatus involved in performing autonomic responses in conditions of emotional activation has received little study. The aim of the present work was to assess the dynamics of evoked EEG synchronization and desynchronization at different frequency ranges during the perception of emotiogenic visual stimuli depending on the extent of accompanying autonomic activation as measured by skin galvanic responses. Studies were performed on 33 students (all right-handed) aged 18-28 years. Difference between subjects with weak (SGR(-)) and strong (SGR(+)) skin galvanic responses were seen only in the theta1 range (4-6 Hz). At the stage at which emotiogenic information was perceived (the first second after the start of stimulus presentation), both groups showed similar dynamics of increases in evoked synchronization in the parietal-temporal-occipital areas of the cortex, with greater involvement of the right hemisphere. From the second second to the end of presentation (2-6 sec), emotiogenic signals gave significantly greater levels of evoked synchronization in these cortical areas as compared with neutral stimuli, and only in the SGR(+) group. These data provide evidence for the involvement of the posterior areas of the cortex of the right hemisphere in the mechanisms of motivational attention and sympathetic activation.