Cognition in motor learning: Imagery effects on contextual interference

Some of the cognitive activities operating to produce contextual interference effects were investigated by manipulating imagery practice and physical practice. In the first experiment, a factorial combination of physical practice conditions with imagery practice conditions was employed to examine the influence of random vs. blocked imagery practice on the expected retention advantage of random over blocked physical practice. Subjects acquired four movement patterns to predetermined criterion performance levels and were subsequently tested on immediate (10 min) and delayed (two week) retention. Random imagery, regardless of whether it was combined with blocked or random physical practice, was found to facilitate retention compared to blocked imagery on both retention tests. In experiment 2, the benefit of random imagery was compared to equivalent amounts of random physical practice and random physical practice with rest intervals. Subjects, under a random practice schedule, either physically practiced movement patterns, physically practiced movement patterns with a rest interval between patterns, imaged movement patterns, or imaged irrelevant items while acquiring three movement patterns. In addition to these conditions, a blocked physical practice control group also was included. Both immediate and delayed retention tests followed the acquisition of the movement patterns. Random imagery practice (relevant or irrelevant) was shown to cause as much interference during acquisition and as much benefit to retention as random physical practice. Random physical practice with a rest interval produced slightly less interference during acquisition but facilitated retention as much as the other random practice conditions. These results indicate the importance of cognitive processes in the contextual interference effect.