Long-term retention and reconsolidation of a visuomotor memory

Visuomotor adaptation is a form of motor learning that enables accurate limb movements in the presence of altered environmental or internal conditions. It requires updating the mapping between visual input and motor output, and can occur when learning a new device/tool or during rehabilitation after neurological injury. In either case, it is desirable to stabilize, or consolidate, this visuomotor memory for long-term usage. However, reactivation of a consolidated memory, whether it is motor-based or not, is thought to render it temporarily fragile again, and thus susceptible to interference or modification. Here, we determined if visuomotor memories demonstrate long-term retention but are fragile once reactivated. We used prism lenses to create a novel visuomotor mapping, which participants learned while having to walk and step to the center of targets. We re-tested this memory after one week and one year. We found that the mapping is retained for at least one year, regardless of whether participants were exposed to an interfering (i.e., opposing) mapping in the first session. We also found that presenting an opposing mapping in a block of trials following reactivation of the memory one year later did not disrupt subsequent performance when we re-tested the original memory. Our results suggest that these visuomotor memories are stored for extended periods of time and have limited fragility. Taken together, our results highlight the robustness of visuomotor memories associated with walking.