白ねずみに於ける社會的學習

Abstract

From a logical point of view, social learning, in which a follower rat learn response in the presence of a leader rat responding to a cue, can be regarded as a type of discrimination learning. Therefore, in order to test the continuity controversy over the role of reinforcement, a reversal experiment, combined with social learning experiment, was conducted. Each of 45 rats was run after a leader rat 8 times a day, upon a simple T maze, after 24 hours of food deprivation. In the 1st experiment (Fig. 2-5), rats were rewarded with food for their right responses, but were punished with mild electric shock for their responses to the irrelevant cue; in the 2nd experiment (Fig. 6-8) they were not punished but only withheld food reward for their incorrect response. The experimental situation is shown in Fig. 1.The rats were divided into 6 kinds of groups, the required responses of which were the following: (1) non-imitative, positional response (Fig. 2); (2) non-imitative, discrimination of the lamp, without reversal training (Fig. 3, group II, and Fig. 6); (3) imitative response, without reversal training (Fig. 4, Group II, and Fig. 7); (4) inverse-imitative response (Fig. 5 and Fig. 8); (5) non-imitative, discrimination of the lamp, with reversal training (Fig. 3. group V); (6) imitative response, with reversal training (Fig. 4. group VI)Respective cues to the right responses were (1) kinaesthetic or spacial orientation; (2) and (5) a lamp switched on; (3), (4) and (6) the leader's response to positional or lamp cues.The criterion of the problem solution was defined as the achievment of the performance, in which the rat shows no longer as many as 25% errors.Taking the total number of trails before the completion of learning as an index of the learning speed of the rat, a comparison of the performances of the above groups gives the following results:1) in the presence of the leader rat, a positional response irrespective of the leader rat was most easily acquired.2) in the presence of the leader rat, discrimination of the lamp was comparatively easily acquird, and the behavior of the non-imitator was stable.3) imitation of the leader rat was apparent, but the behavior of the imitator was not so stable as that of the non-imitator.4) the inverse-imitation of the behavior of the leader rat was almost unseccessful.5) the retardating effect of the reversal training was not perceived in the groups of both imitative and lamp discrimination.