"Inner" darts: effects of mental practice on performance of dart throwing.

To explore the effects of mental rehearsal on the performance of a motor skill, 32 college undergraduates were scored on dart-throwing ability and randomly assigned to one of 4 practice conditions: no-practice controls, mental rehearsal only, mental rehearsal with simulated dart-throwing motor movements, and direct physical practice. Following 6 days of mental or physical practice by the experimental groups, the performance level on the dart-throwing task was again measured for all subjects. Comparison of improvement showed statistically significant differences between the groups. Follow-up tests showed that all experimental groups differed significantly from the no-practice group, there were no significant differences between mental practice groups and direct physical practice resulted in improvements significantly higher than any other form of practice.