Exploring techniques for encoding spoken instructions in working memory: a comparison of verbal rehearsal, motor imagery, self-enactment and action observation.

Encoding and recalling spoken instructions is subject to working memory capacity limits. Previous research suggests action-based encoding facilitates instruction recall, but has not directly compared benefits across different types of action-based techniques. The current study addressed this in two experiments with young adults. In Experiment 1, participants listened to instructional sequences containing four action-object pairs, and encoded these instructions using either a motor imagery or verbal rehearsal technique, followed by recall via oral repetition or enactment. Memory for instructions was better when participants used a motor imagery technique during encoding, and when recalling the instructions by enactment. The advantage of using a motor imagery technique was present in both verbal and enacted recall. In Experiment 2, participants encoded spoken instructions whilst implementing one of four techniques (verbal rehearsal, motor imagery, observation of others' actions or self-enactment), and then recalled the instructions by oral repetition or enactment. For both verbal and enacted recall, memory for instructions was least accurate in the rehearsal condition, while the other encoding conditions did not differ from each other. These novel findings indicate similar benefits of imagining, observation and execution of actions in encoding spoken instructions, and enrich current understanding of action-based benefits in working memory.