実験的消去について (1) 一つの反応系の消去が他の反応系の学習におよぼす効果

抄録

In this paper, the effect of an experimental extinction on another response process is reported. The problem is whether the experimental extinction of a conditioned response (lever pressing in a Skinner box) improves or inhibits the learning of another response (running response in a runway).
Subject: Thirty-five female and twenty-six male white rats, six to seven months of age and 192.5g of mean weight, were used.
Apparatus: A corridor-type runway connected with the Yagi-type Skinner box, as shown in Fig. 1, was adopted, Dotted lines doors, the door of the S box being a guillotine door and that of the G box, a hinged door. L denotes a lever and circles, food dishes.
Procedure: All rats were first trained on bar pressing (a pellet, 50mg, for each pressing) in the S box and then the doors of the S and G boxes were so opened as to make the rats adapt themselves to the whole apparatus (S, R, G, in Fig. 1). In the test the subjects were divided into four groups. As soon as the lever pressing in the S box was extinguished under four conditions mentioned in Table 1, the door of the S box was opened and the response time (latency plus running time) to the G box was daily measured for one trial for ten days. They received three pellets (150mg) in the G box.
Each rat in four correspondent control groups was first detained in the S box without a lever for each assigned period mentioned in Table 2, the detained period of each group corresponding to the time required by each experimental group to reach its own criterion. The door of the S box was then opened and the response time to the G box was daily measured for one trial for ten days.
Results: As shown in Fig. 2, the groups of longer extinction (G3 and G4) were slower in running response to the G box than the remaining groups. It might be due to the generalization of extinction, and the results of these groups corresponded to those of C3 and C4 which were lower in running response to the G box than the residual control groups.
On the other hand, G2 in which the bar pressing was extinguished for a relatively short time tended to be even faster in running response than G1 of still shorter extinction, although the statistical difference was not significant. The running time of G2 did not correspond to that of C2 which was slower than C1. It is herein implied that there may be some mechanism in a short time extinction to facilitate the running response.
As to the control groups, those which were longer detained in the S box were also slower in running response to the G box, and this might be due either to the difficulty to know when the door of the S box would be opened, or to the adaptation to the S box.
As shown in Table 3, a statistical analysis of the time of running from the S to the G box indicated that there was. a significant difference among the subgroups, G1 to G4 and C1 to C4, and also between the experimental and control groups, although no significant difference was found between G1 and G2.
Conclusions: A relatively short time extinction in one response neither reduces the response tendency of another response nor inhibits its learning, but rather facilitates the learning of another response. It may therefore be suggested that an increment (ΔD) in the original drive is produced by a short time extinction and ΔD×H, the effect of this increment on E (reaction potential) is larger than the inhibition made by the short time extinction.
Though ΔD may also be produced by a long time extinction, ΔD×H or the effect of ΔD on E is not larger than the inhibition made by the long time extinction, as shown in Fig. 3. The inhibition mentioned above implies generalized from the bar pressing to the runway response.
A strong tendency toward a running response in G2 even in the first trial when the presence of food in the