The Effects of Mental Practice on Motor Skill Performance: Critical Evaluation and Meta-Analysis

Abstract

Empirical research suggests that mental practice may enhance the performance of motor skills. Many variables have been shown to mediate the size and direction of the mental practice effects. The purpose of the present study is to provide an overview of research examining the role played by these variables in mediating the effectiveness of mental practice. In order to integrate the findings in the literature and to further analyze the relative contributions of each of these variables, a meta-analysis was performed according to the procedure outlined by Smith, Glass, and Miller. Twenty-one studies that met the criteria of having both an adequate control and a mental practice alone group were included in the meta-analysis. The forty-four separate effect sizes resulted in an overall average effect size of .68, (SD = .11) indicating that there is a significant benefit to performance of using mental practice over no practice. A series of General Linear Models revealed that the use of “internal” imagery produced a larger average effect size than the use of “external” imagery, and that mental practice sessions of less than one minute or between ten and fifteen minutes in length produced a larger average effect size than sessions of three to five minutes in length. These findings suggest the complexity of the relationship between variables that influence mental practice.