Experiments through “Response-Alternation” Method for Extinction and Spontaneous Recovery in White Rats

Abstract

Part 1. The aim of the first experiment was to examine whether extinction may be viewed as due to the changed direction of a psychological resultant force f* _{A, G} by providing a situation where two paths W _{A, E, G} and W _{A, F, G} in jumping apparatus lead to the same psychological goal (food reward) from the same jumping stand (See Fig.1).
Thirty-four male and female albino rats were given preliminary trials along each path. After these trials, they were divided into three groups, and were trained to jump along the path W _{A, E, G} with continuous (RR) and partial (RU and UR) reinforcement (food reward as indicated by R in Table 1) in the acquisition period of 31 trials. In the period of extinction procedure (U₁, U₂, .......... U_n, in Table 1), the resistance to extinction was measured by the number of trials along the path W _{A, E, G} before the subject substituted W _{A, F, G} for W _{A, E, G} in order to reach food.
Group RR showed much less resistance to extinction than the other groups. Between Groups RU and UR statistically significant difference was found (See Table 3). These results indicate that after continuous reinforcement the psiychological force f _{A, G} is much more changeable in direction than after partial reinforcement, and these facts mean that extinction can be viewed as due to the changed direction of a psychological resultant force f* _{A, G.}
Part II. The aim of the second experiment was to examine the effects of “relative” effortfulness (rk) of the conditioned, (continuously reinforced) response to that of the alternative response upon extinction and spontaneous recovery, by providing a situation where two paths, i. e., W _{A, E, G} and W _{A, F, G} lead to the same goal from the same starting-point : a runway maze with an electric grid at the first step of alley in the path W _{A, F, G} (5 Volts for Group I and 20 Volts, for Group II) (See Fig. 3). Hodologically, in this situation, the occurrence of the alternative response, i. e., locomotion along the path W _{A, F, G} would mean that the psychological force has changed its direction from d_{A, E, G} to d_{A, F, G}.
Twenty-two male and female albino and pigment rats were given at first running training in the straight runway. After the training, they were divided into two groups (Group I and Group II), and were given preliminary trials along each, path. They were, then, reinforced for running along the path W _{A, E, Q} in the acquisition period of 16 trials. In the period of extinction procedure, the resistance to extinction was measured by the number of trials along the path W _{A, E, G} before the subject substituted W _{A, E, G} for W _{A, F, G} in, order to reach food.
Group I showed much less resistance to extinction than Group II (See Table 4) : the greater the “relative” effortfulness of a response, the smaller the resistance to extinction. There could also be found a statistically significant difference in the tendency to spontaneous recovery between the two groups : the greater the “relative” effortfulness of a response, the weaker the tendency to spontaneous recovery.