Chronometric comparisons of imagery to action: visualizing versus physically performing springboard dives.

Motor imagery research emphasizes similarities between the mental imagery of an action and its physical execution. In this study, temporal differences between motor imagery and its physical performance as a function of performer expertise, skill complexity, and spatial ability were investigated. Physical execution times for springboard dives were compared with visualized execution times. Results indicate that physical and visualized performance times were not identical: Their relation is a function of dive complexity and diver expertise, but not their interaction. Relative to physical time, visualization time increased with increased complexity, suggesting the involvement of capacity-limited working memory. A nonmonotonic relation was found for expertise: Unlike experts or novices, visualization time for intermediates was significantly slower than physical time. These temporal differences are most consistent with schematic differences in skill representation. Intermediates may be relatively slowed by greater amounts of nonautomatized knowledge, as compared with the automatized knowledge of experts or the sparse knowledge of novices.