Effects of CS only trials on resistance to extinction of an avoidance response.

Abstract

Rats, trained to avoid shock in a 1-way box to a criterion of 2 successive avoidances, received either 1, 5, or 20 additional CS [conditional stimulus] only trials after appropriate delays. 24 hr. later, Ss [subjects] that received only 1 CS only trial immediately after reaching criterion extinguished rapidly whereas other Ss, including Ss which received 1 additional CS only trial after a 40-min. delay, showed significantly greater resistance to extinction. The results were interpreted as suggesting that relaxation-produced stimuli, when conditioned to the avoidance response, can elicit and maintain avoidance responding.