Developmental Changes in MEG Oscillatory Activity During Visuomotor Adaptation: Differential Maturation of Feedforward and Feedback-related Mechanisms.

Visuomotor adaptation, the ability to recalibrate movements using visual feedback, continues to mature throughout childhood, yet the neural mechanisms driving this development are not well characterized. We recorded magnetoencephalography (MEG) in children (6-12 years) and adults as they reached visual targets under a 45° cursor rotation and examined cortical oscillations at two movement stages, before peak velocity (predominantly feedforward) and after it (predominantly feedback-based). Both child and adult groups showed adaptation in their cursor movements, and older participants were faster, more accurate, and less variable in their movement timing. During feedforward planning, children showed reduced pre-movement beta synchronization and weaker post-stimulus beta desynchronization in the motor, parietal, and occipital cortices, consistent with a less mature feedforward process. Children also showed more prominent, sustained prefrontal theta activity following target onset, consistent with greater reliance on executive control. During the deceleration period after peak velocity, group differences were reduced, suggesting that predominantly feedback-based movement correction is closer to adult-like function than feedforward planning, although not yet fully mature. Brain-behavior relationships also differed by age: neural oscillations were more tightly coupled to task performance in children than in adults, suggesting that maturation is still ongoing in this age range. Together, these findings suggest that the development of visuomotor adaptation is not a uniform process. Rather than developing as a single capacity, feedforward execution and feedback-based error correction follow graded maturation timelines.