Learned helplessness and immunization with different escape responses in rats

Abstract

Two experiments were conducted in order to test the learned helplessness and the immunization effects as a function of the activity level of the escape responses: the jumping and the nose poking, classified as active and passive responses, respectively In experiment 1, rats were divided in four groups exposed to two sessions. On the first session, the rats were submitted to uncontrollable shocks or no shocks treatment, followed by the second session where they were exposed to an escape procedure with the jumping or the nose poking responses. In experiment 2, six groups of rats were exposed to three sessions. On the first session, some rats had the opportunity to escape the electric shocks by performing the nose poking response, others received uncontrollable shocks or no-shocks. On the second session, half of animals from each group was exposed to uncontrollable shocks and half was exposed to no-shocks. On the third session all rats were tested for escape shocks by performing the jumping response. The results showed that the learned helplessness effect was equally observed with active or passive responses, and that the training with a low activity response immunized the rats against the learned helplessness. These results are discussed considering the learned helplessness and the learning inactivity hypotheses.