Objectives Motor imagery (MI) is a dynamic mental state during which the representation of a given motor movement is rehearsed in working memory without overt motor output. Mental practice (MP; also known as motor imagery practice) is the systematic application of MI for the cognitive rehearsal of a task in the absence of overt physical movements. Although MP is known to enhance skilled performance, debate still exists about the magnitude and moderators of these imagery effects. Against this background, and amid concerns about the “reproducibility crisis” in psychology, it seems timely to revisit, update and extend a key meta-analysis of MP effects published over two decades ago – namely, that of Driskell, Copper, and Moran (1994). To this end, the present paper reports a methodological replication of the Driskell et al’s (1994) meta-analysis of MP effects. Design & method Included are 37 studies on MP effects published between 1995 and 2018. Nine factors were selected to examine the extent to which they moderate the effectiveness of mental practice, providing a window into the conditions under which mental practice is most effectively implemented. Practice Type (Mental or Physical), Expertise, Duration of practice (both program and session), Task Type, and Control Type were retained as factors of interest from the original Driskell et al. (1994) meta-analysis. In order to further explore the nuance of mental practice implementation, we additionally examined the Imagery Type, the Performance Measure used, Activity Type (team versus individual activities) and the Setting of the intervention. Results Following publication bias analyses, our results confirm that overall, MP has a small but significant positive effect on performance (r = 0.131). Moderators of this beneficial effect were MP duration, type of task and type of imagery used. Conclusions We conclude that MP has an enduring positive influence on performance.
