Effect of electrical stimulation of the posterior cingulate cortex on acquisition of active avoidance response in cats.

Five groups of cats were studied in a two-way shuttle-box. Groups I, II and III were trained with electrical stimulation of the cingulate cortex applied simultaneously with the CS (light), Group IV with the light stimulus only, and Group V with electrical stimulation of the cingulate cortex as the CS. The comparison of the number of training sessions to attain a criterion showed that electrical stimulation of the posterior part of the cingulate cortex may facilitate the process of acquisition of the conditioned active avoidance response. The facilitatory effect was not accompanied by overt somatic and vegetative changes which suggests a direct participation of the stimulated area in the control of emotional-defensive behavior. It may be presumed that a faster acquisition of AAR was due to a better recognition of the events occurring in the environment and consequently to more rapid CS-US association.