Engagement of motor and perceptual awareness when learning to reach with mirror reversed feedback

In mirror reversed (MR) learning, the magnitude and direction of the visuomotor distortion varies with target location. To date, implicit (i.e., unconscious) processes have not been implicated in learning to reach with an MR distortion, even when the distortion is small in magnitude. Across two experiments, we examined whether explicit processes (i.e., motor and perceptual awareness of reaching strategies) are engaged when learning to reach with a small (20°) MR distortion and whether this learning generalizes to novel targets. Learning to reach with an MR distortion was compared to learning to reach with a small visuomotor rotation (VR), in which cursor feedback was rotated 20° relative to hand motion at each target. Participants in the MR group engaged both motor and perceptual awareness and learning to reach with the MR distortion generalized to novel targets. Participants in the VR group also learned to reach with the VR distortion but they did not engage either motor or perceptual awareness and there was no evidence of generalization. Reaction times were longer for the MR group compared to the VR group, consistent with engagement of explicit processes. Together, these findings suggest that learning to reach with an MR distortion is supported by motor and perceptual awareness that generalize to novel targets.