Movement Kinematics of Prepotent Response Suppression in Aging During Conflict Adaptation

The purpose of the current study was to explore the role of adjustments in motor control and conflict adaptation in younger and older adults' prepotent response suppression. Participants performed repeated pairs of key-presses on a piano-type keyboard as well as key-presses that conflicted with that prepotent pair. We used motion capture to assess cognitive and motor contributions to conflicting responses presented once, twice, or three times within single trials. Older adults performed the first conflicting response in a series as well as young adults but at a cost to prepotent response performance. Younger adults improved performance with increased conflict frequency, whereas older adults did not. Older adults spent less time planning and more time executing their conflicting responses, with the opposite pattern in younger adults. Overall, increasing the frequency of conflicting response presentation was detrimental to older but not to younger adults' prepotent response performance. In addition, the results indicate an age-related decline in conflict adaptation. The results are discussed in terms of current models of cognitive control.