Haptic Connection to a Partner Enhances Motor Learning Retention in Older Adults: Implications for Multiplayer...

There is a growing interest in understanding how haptic communication between individuals can improve motor learning, particularly in the context of robotassisted neurorehabilitation. Multi-user robotic systems can haptically connect patients, caregivers, and/or clinicians, providing an implicit communication channel and increasing engagement through multiplayer games. Previous studies of haptic communication and motor learning, however, have focused on pairs of healthy young adults completing relatively simple robot-based tasks. We present a study investigating older adults learning a 1-degree-of-freedom robot-based pursuit tracking task under two conditions: solo and dyad. We evaluated the evolution of motor performance in 38 trials with 1-week follow up. We found no between-group differences in tracking error at any time point. Within-groups, we observed significantly lower tracking error at both the same-day assessment and 1-week retention compared with baseline for both the more skilled and less skilled members of the dyads, whereas the solo group showed no significant improvements across trials. Learning curve analysis further demonstrated superior retention in the less skilled dyad partners relative to the solo group. During the interaction trials, the less skilled partner decreased their tracking error while the more skilled partner maintained performance. We also note exaggerated movements and increased effort from the more skilled partners in the dyads, which may suggest the emergence of a leader-follower dynamic. Together, these findings indicate that training with a haptic connection to a partner yields modest benefits for motor learning in older adults, with the strongest evidence for improved retention among the less skilled partners.