Hemispheric quantitative EEG changes following emotional reactions in neurotic patients

Twenty-four right-handed patients undergoing primal therapy served as subjects in the study. They all showed symptoms of tension, anxiety, and/or depression. The patients' right and left temporal EEGs were recorded immediately before and after a therapy session. Recordings were done while the patients were resting, and while they were performing a verbal and a visual task with their eyes closed. The EEG data were analysed off-line with a computer, using quantitative amplitude analysis in the 1.5 to 30 Hz frequency band. A "high intensity" group (n = 13) having high ratings of emotional activity in their therapy session was compared with a "low intensity" group (n = 11) with low ratings. The results showed that only in the "high intensity" group was there a significant increase in mean amplitude and amplitude variance in the right hemisphere, measured across conditions. A between-group comparison revealed that the "high intensity" group showed a significantly larger increase in right hemisphere variance and in right over left variance ratio, relative to the "low intensity" group, in which these variables were almost unchanged. These results indicate a greater involvement of the right hemisphere in emotional activity. It is also suggested that the EEG changes found in the "high intensity" group, following a therapy session, reflect a general deactivation of the brain and a functional improvement of the right hemisphere.