PREFRONTAL BRAIN ASYMMETRY - A BIOLOGICAL SUBSTRATE OF THE BEHAVIORAL-APPROACH AND INHIBITION SYSTEMS

Resting anterior brain electrical activity, self-report measures of Be havioral Approach and Inhibition System (BAS and BIS) strength, and ge neral levels of positive and negative affect (PA and NA) were collecte d from 46 unselected undergraduates on two separate occasions. Electro encephalogram (EEG) measures of prefrontal asymmetry and the self-repo rt measures showed excellent internal consistency reliability and adeq uate test-retest stability. Aggregate measures across the two assessme nts were computed for all indices. Subjects with greater relative left prefrontal activation reported higher levels of BAS strength, whereas those with greater relative right prefrontal activation reported high er levels of BIS strength. Prefrontal EEG asymmetry accounted for more than 25% of the variance in the self-report measure of relative BAS-B IS strength. Prefrontal EEG, however, was not significantly correlated with PA or NA, or the relative strength of PA versus NA. Posterior as ymmetry was unrelated to the self-report measures.