INFANTILE HANDLING AND ASSOCIATIVE PROCESSES OF RATS

A review of the literature on the effects of infantile handling indicated that this variable has an effect upon the animal's later performance on various learning tasks. This effect may be the manifestation of at least two possible processes. As a result of its direct effects on the emotional as well as exploratory responsivity of the rat, infantile handling has an indirect effect upon the animal's associative learning processes. Because the learning criteria used in previous handling studies involve an increase in an animal's operant level of goal‐directed activity, it is difficult to determine whether handling directly facilitates later learning. On the other hand, the results of studies of the effects of handling upon tasks where activity level increase is not confounded with learning would yield less ambiguous outcomes than those from earlier experiments. The aim of the present experiment was to train handled (H) and non‐handled (NH) rats in a brightness discrimination learning situation and to examine the effects of punishment in that context. The fact that NH animals required fewer trials than H animals to relearn the formerly punished response suggests the possibility that H animals show greater retention of the learned fear response (hence greater associative ability) than NH animals.