Neural correlates of individual differences in motor learning under reinforcement contexts.

Rewards and punishments shape motor learning, yet individuals vary in their adaptation speed and skill retention. Previous studies have linked these processes to two electroencephalographic signatures: feedback-related negativity (FRN) and sensorimotor event-related desynchronization (ERD). However, their roles in individual learning differences remain unclear. We recorded electroencephalography while 64 adults performed a visuomotor rotation task where gains or losses scaled with movement error. Using Lasso regression, we examined whether these neural markers accounted for individual variability in learning and retention. Results demonstrated that the interaction between sensorimotor alpha-ERD during movement preparation in late adaptation and feedback condition explained retention. Stronger alpha-ERD predicted better retention only in the reward condition, whereas neither ERD nor FRN explained adaptation rates. These findings indicate that late-phase alpha-ERD reflects neural mechanisms supporting motor memory stabilization, which becomes behaviorally relevant specifically under positive reinforcement. Thus, pairing reward with interventions enhancing sensorimotor cortical excitability may facilitate skill maintenance.