The role of cognition for different stages of visuomotor adaptation in younger and older adults.

A recent model identified three stages of learning, the first drawing on cognitive flexibility, the second on inhibition, and the third on automation. We explored the validity of this model for visuomotor learning and found that adaptation is associated with inhibition early during adaptation and with automaticity later on. An initial association with cognitive flexibility remained inconclusive. This work employs another marker of cognitive flexibility and extends our work to older adults. Twenty young and 20 older adults completed three cognitive tasks (switch task, Stroop task and four-choice-reaction-time-task). They performed a visuomotor adaptation task under 60° rotation of visual feedback. Based on their cognitive scores, participants were divided into good and poor performers. Young adults outperformed older adults in visuomotor adaptation tasks and in cognitive tasks. Switch task performance was not associated with adaptation in either age group. Stroop performance was associated with early and four-choice-reaction-time-task with late adaptation in young adults. In older adults, Stroop performance was associated with early as well as late adaptation whereas four-choice-reaction-time-task was not associated with adaptation. All associations were present during adaptation, but not during de-adaptation. Our findings do not confirm the existence of the first postulated learning stage for the case of adaptation. They support the second and third stage in young persons for strategical components of adaptation. In older adults, the duration of the second stage seems to extend so that the third stage was not reached within the duration of our experiment. We conclude that degraded cognition in older age could explain why adaptation is impaired while aftereffects remain intact.