Wakeful targeted memory reactivation during short rest periods modulates motor learning via the lateral orbitofrontal cortex network

Abstract

This study investigated whether wakeful targeted memory reactivation (TMR) during short rest intervals improves motor learning. Participants were randomly assigned to the following four groups and performed a sequential key-press task under each condition: (1) TMRno group: no auditory stimuli, (2) TMRregular group: auditory cues played at the same speed as the previous task, (3) TMRfast group: auditory cues played 1.3 times faster, and (4) TMRrandom group: auditory cues randomized in pitch. The TMRregular group suppressed early learning gains compared with the TMRno and TMRfastgroups. Electroencephalogram revealed reduced functional connectivity centered on the lateral orbitofrontal cortex (lOFC) in the TMRregular group. In contrast, the TMRfastgroup preserved early learning and exhibited improved lOFC-centered functional connectivity compared with the TMRregulargroup. Therefore, wakeful TMR might either hinder or support motor learning, depending on cue timing and structure, emphasizing the need to optimize sensory parameters for effective learning improvement.