Spatial Dynamics Shape the Interaction Between Motor Adaptation Processes

Motor adaptation relies on explicit aiming strategies and implicit recalibration, but their interaction and effects on implicit skill learning remain debated. While these processes were initially thought to combine linearly, recent research challenges this view, though spatial and temporal dynamics may have confounded these findings. Specifically, implicit recalibration peaks at where individuals aim their movements, and adaptation operates across multiple timescales, with both stable and volatile components. To examine whether these factors mask the true relationship between explicit strategies and implicit recalibration, we conducted a visuomotor rotation task that obtained independent measures of both processes while accounting for spatial and temporal dynamics. After controlling for task instruction clarity and spatial dynamics (plan-based generalization), we found a strong but subadditive relationship between explicit strategies and implicit recalibration, with temporal dynamics showing minimal influence. This sub-additivity may stem from methodological imprecision or nonlinear interactions between processes.