A randomized controlled trial of mental imagery augment generalization of learning in acute poststroke patients

Our previous studies demonstrated that mental imagery intervention enhanced poststroke patients relearning daily task performance. This study aimed to test the efficacy of mental imagery for promoting generalization of the task skills learned in a training environment to trained and untrained tasks carried out in a novel environment.

Thirty-five acute poststroke patients were randomly assigned to the mental imagery (MI; n=18) or conventional functional rehabilitation (FR; n=17) group. The MI intervention was 3-week standardized practices and daily tasks using the chunking-regulation-rehearsal strategies. Outcome measurements were the performances on trained and untrained tasks in the training and novel environments.

The MI patients showed significantly better performances on 4 of 5 trained tasks (P=0.001 to 0.026) versus only 1 task in the FR patients (P=0.021). The MI patients also outperformed their FR counterpart on the 3 (of 5) (P=0.025 to 0.049) trained and 2 (of 3) untrained tasks (P=0.042 to 0.045) carried out in the novel environment.

The mental imagery intervention was useful for improving patients' ability on performing the tasks which they did not previously trained on and in places different from the training environments. These involved generalization of the skills learned at the task performance level. Our findings are limited to poststoke patients who share similar characteristics with those in this study.