Abstract

The present study assessed traditional reaction time and accuracy as well as novel kinematic measures of younger (YA) and older (OA) adults performance on a fine motor/cognitive task using a midi keyboard and 3-D motion capture. The goal of the study was to assess the role of executive control in the production of sequential key presses that required spatial information learning. To this end, certain finger transitions were made pre-potent by manipulating their repetition frequency (presented 1, 3, or 5 times) within each trial during 3 learning blocks. These critical transitions (CT) were then used to create violation transitions (VT) presented during 3 testing blocks, that violated the pre-potent responses and required greater executive control. When learning was equated, OA were more affected in terms of reaction time by the VT than YA, suggesting that OA had more difficulty with the task when greater executive control was necessary. When key press responses were parsed into kinematic components, the results showed that OA spent more time planning their movements than YA. Crucially, when YA performed predictable CT they were found to slow down their key press execution, making smooth responses, whereas OA made rapid responses regardless of response predictability. This may be interpreted as a compensatory strategy of OA to overcome slowed movement planning. The results are discussed in terms of system-based theories of cognitive aging with an emphasis on the role of motor control processes in cognitive performance.