Gesturing helps memory encoding in aMCI.

Encoding in episodic memory is a step often impaired in patients with amnestic Mild Cognitive Impairment (aMCI). However, procedural memory processes are still relatively preserved. In line with previous research on the enactment effect, we investigated the potential benefit of encoding words combined with imitative gestures on episodic memory. Based on the Grober and Buschke's free/cued recall procedure, we developed the Symbiosis test in which 13 patients with aMCI and 16 healthy elderly participants learned 32 words belonging to 16 different semantic categories either in a verbal encoding (A) or a bimodal (B; verbal and motor imitation) condition, using a blocked ABBA/BAAB procedure. Overall, memory retrieval was better in healthy participants than in patients with aMCI, and better for cued retrieval in the bimodal encoding (gesture cues) than the verbal encoding (category cues) condition, but there was no interaction effect between group and encoding conditions. These results show that performing concomitant gestures can enhance cued episodic memory retrieval in patients with aMCI and in healthy elderly controls. The Symbiosis test broadens the scope of the enactment effect, from action phrases to isolated words learning in patients with aMCI. Future work should investigate how bimodal encoding provides novel perspectives for memory rehabilitation in patients with aMCI.