Involvement of Perimovement Neural Beta-Oscillations in Strategic Aiming for Motor Adaptation.

Humans rely on cognitive strategies to adapt upcoming movement in response to past movement error, for example, by strategic reaiming. We show that strategy-based motor adaptation engages premovement and postmovement neural oscillations in the beta frequency band. We recorded electroencephalography (EEG) while healthy participants (N = 27) performed center-out reaching movements to move a cursor on a screen through a visual target. In some trials (17%), the cursor was unexpectedly rotated relative to the hand. This rotation was either repeated in the next trial, so that participants could reaim their reach in that trial (2× condition), or the rotation was switched off, preventing reaiming (1× condition; within-subject design). We found a stronger decrease in postmovement beta rebound (PMBR) after the first rotation in the 2× condition, compared to the 1× condition, despite similar movement kinematics. This indicates a role of PMBR in strategic reaiming, and replicates findings from our previous study (Korka et al., 2023). Combining data from the two studies (total N = 52), we found that reaiming accuracy was associated with premovement beta power in the second rotated trial, but not with the PMBR decrease at the end of the first rotated trial. Our results indicate that the decrease in PMBR upon movement error signals the need to adjust a cognitive strategy. Such a role may explain how reduced PMBR in Parkinson's disease could impair discovery of cognitive strategies for movement. Premovement beta power, on the other hand, may be involved in the specification of an aiming strategy following erroneous movement.