Spatial distribution of human motor adaptation effects under unidirectional visuomotor inconsistency

Whether the adaptation effect to unidirectional motion in a visuomotor inconsistent environment has directional specificity has not yet been generalized. This study aimed to investigate whether adaptation effects, acquired from learning to move in a specific direction, manifest in subsequent movements within the same or different directions postadaptation to the mismatched environment. Participants were provided visual feedback of their arm movements, which was manipulated to either suppress or enhance their motions. Through training, participants adapted to this inconsistency between visual and motor feedback. Subsequently, they performed a reaching task with visual information blocked. Results showed that the adaptation effect persisted in postadaptation movements within the same direction as the training, even in the virtual environment. Surprisingly, this effect also extended to movements in different directions. These findings elucidate the spatial characteristics of the adaptation effects of simultaneous adaptation to both vision and motion, thereby contributing to future research in this field.