Is light increment really rewarding to the rat?

Abstract

A review of existing literature reveals no satisfactory demonstration that light increment can act as a reward for the rat, if a "reward" is taken to mean an event that reinforces, or promotes the learning of, an instrumental response that it closely follows and if "learning" is taken to mean an effect that lasts at least 24 hr. Two experiments, in which rats were given training trials, interspersed with test trials, at intervals of 1 day are reported. Controls for positive-feedback facilitation, conditioned arousal, number of responses during training trials, and novelty of test conditions were present. The results permit the conclusion that light increment can act as a reward.