Measurement of current flow through the rat under signaled and unsignaled grid-shock conditions

Abstract

The present experiment was run to test the hypothesis that, when shock was signaled, rats would develop effective coping responses so as to reduce the current flow through them. A 1-sec shock was delivered through a grid floor by a fixed impedance ac shock source. The current-flow measure was taken over the last 30 of 90 trials given over 3 days and indexed by “gross skin conductance” or GSC (shock). The rat under the signaled shock condition (n=15) showed higher GSC (shock) than did the rats under the unsignaled shock condition (n=14). Thus, the result contradicted the hypothesis. There was no indication that the rats developed any preparatory response during the 5-sec signal, in terms of either GSC (signal) or posture. The results were discussed with reference to the preparatory-response hypothesis and various other possibilities.