A STUDY ON THE CANCELLING IN MOTOR PROGRAM / 体力科学

ABSTRACT

In order to find out what changes would happen to the cancelling in the course of the program and what differences would be caused in the cancelling ability depending on the degree of program formation, we examined the changes of adults (in their 20s and 50s) and children, and obtained the following results.<BR>1. In the cases of cancelling actions halfway, delays in the reaction time and movement time of both the adults and children were found, unlike the cases of controlling actions. This tendency was noted remarcably in the adults at their age of 20s and in the children.<BR>2. The time for the switching into the next actions by cancelling the previous actions was found to be the longest at the initial stage when the action program was intiated.<BR>3. The fluctuation in the movement times immediately after initiating actions was extremely small in both controlling and cancelling actions. However, as the actions advanced, the values of the cancelling actions showed larger fluctuations. This trend could be noted very significantly in both the adults at the age of their 20s and the children.<BR>4. The time of delays by more than 20 over the mean value in both the time for reaction and the time for movements were noted more frequently in the cancelling actions especially in the latter half of the actions where the actions advanced.<BR>5. The emergence of erroneous action (miss-touch) for cancelling to stop the actions and to push the next key instead was the most frequent when the cancelling was made at the initial stage of the action, and the rate of miss-touch was invariably approx. 50% at any age. As the actions advanced, the frequency of miss-touch decreased.<BR>On the basis of the above findings, it can be concluded that the earlier it is in the course of proceeding with the program, the more it is difficult to cancel the program in the central nerve system for cancelling the on-going action, and that, as the program advaces, it is easier to cancel the program. It was furthermore demonstrated that, as the age advanced, the program could be formed more firmly, making it difficalt to cancel the program.