REACTIVATION PROTECTS HUMAN MOTOR MEMORIES AGAINST INTERFERENCE FROM COMPETING INPUTS

Abstract

Memories are often thought to become increasingly stable and resistant to change over time. The reconsolidation framework proposes that reactivating a stable memory transiently increases its susceptibility to modification by subsequent experience, but evidence for such reactivation-induced destabilization remains mixed. Here we tested whether reactivation alters the susceptibility of a visuomotor memory to interference from competing learning. Across a series of motor adaptation experiments, we briefly reactivated a previously acquired memory before introducing an opposing perturbation. Contrary to reconsolidation predictions, reactivation did not increase interference during later retrieval. Instead, reactivation reduced interference when the competing memory was not allowed to stabilize after acquisition. Our findings challenge the view that reactivation universally destabilizes motor memories and instead suggest that it shapes which competing motor memory is expressed at retrieval.