The effect of ventral rhinencephalic lesions on avoidance thresholds in monkeys.

Abstract
9 monkeys were trained in a Sidman avoidance situation in which a lever-press delayed the occurrence of an electric shock. The Ss were then either given bilateral lesions in the orbita-insula-temporal region (OIT), the amygdaloid region (AM), or control operations. After an extinction session the avoidance thresholds were again measured postoperatively. In terms of the first postoperative thresholds and other response indexes, the OIT group showed least avoidance, the AM group next, and the controls most. The extinction results were in the same direction.