Shock escape vs food-rewarded running in a successive discrimination

Abstract

Two groups of rats were trained for 100 trials on a successive discrimination in a runway where on half the trials (S-) nonreinforcement was preceded by an alleyway cue of darkeness or ambient lighting. One group of hungry rats received food as a reward on S+ trials; whne the other group of unhungry rats were shocked in the same runway and reinforced on S+ trials by shock termination in the goalbox, but nonreinforced by 30 sec delay of shock termination on S-trials. Rats given the appetitive training learned the discrimination within 20-30 trials, while those given aversive training showed no evidence of forming a discrimination.