Abstract
In this study, the reaction latency in rats was observed with an elevated straight run way. It was measured during the acquisition and the extinction period, and both results were compared. The rats here used were 21 white rats and 6 pigment rats, and the differences between two groups were compared, too.
Generally speaking, the latency in the acquision period and that in the extinction period did not show the mere inverse relation, and they were different qualitatively. Further, it seemed that there was a some inverse relation between the latency and the reaction potential (or excitatory tendency), but was not always a continuous smooth function like an exponential function. It was a noncontinuous relation, and it was assumed that there was a possibility of some complicated cognitive mechanisms.
As to the individual rats, in spite of the same experimental conditions, there were significant differences between the latency of white rats and that of pigment rats. Therefore, it could be inferred that some factors based on the hereditary and constitutional differences played a considerable role in these processes. Moreover, the measured values of individual rats showed great deviations, particularly in the extinction period.
However, since each rat showed some constant tendencies, it might be possible to adopt them as indexes of the individual differences.
