Two experiments were designed to investigate shock intensity (current level), and shock duration as variables in the conditioning of an avoidance response in rats with a single training trial. In Exp. 3, a fixed current and duration were used and the resistance of the established conditioned response to extinction was determined. A grid scrambled 3-ma., 1-sec. shock applied to the four paws as a reinforcement was found to be most efficient in producing a high incidence and magnitude of conditioned avoidance. Training-testing intervals of 1 and 24 hr. yielded comparable results. Increasing the duration of a 3-ma. shock reinforcement increased the resistance of the CR to extinction.
Role of shock intensity in the learned helplessness paradigm
