Purpose : The purpose of this study was to investigate the effect of mental and physical practice on the learning and retention of the pursuit rotor task. Method : Subjects were 22 male students in Sendai College. The subjects were then randomly assigned to either the physical practice, the mental practice, or the no-practice group used as the control group. Subjects then practiced for 12 days within their specific treatment groups. Results : An analysis of the data revealed the following facts : There was a significant difference at the 1 percent level between the pre-test and the post-test, and between the pre-test and the retention test, for three groups At the post-test, there was a significant difference between the physical practice group and the mental practice (1 percent level) or the no-practice group (5 percent level). The difference between the mental practice and the no-practice group was not significant. Therefore, physical practice was the superior type of practice in performing the pursuit rotor task. At the retention test, there was no significant difference among three groups
