An Implicit Plan Overrides an Explicit Strategy during Visuomotor Adaptation

The relationship between implicit and explicit processes during motor learning, and for visuomotor adaptation in particular, is poorly understood. We set up a conflict between implicit and explicit processes by instructing subjects to counter a visuomotor rotation using a cognitive strategy in a pointing task. Specifically, they were told the exact nature of the directional perturbation, a rotation that directed them 45 degrees counterclockwise from the desired target, and they were instructed to counter it by aiming for the neighboring clockwise target, 45 degrees away. Subjects were initially successful in completely negating the rotation with this strategy. Surprisingly, however, they were unable to sustain…