Dual-task performance reveals increased involvement of executive control in fine motor sequencing in healthy aging.

The purpose of the current study was to examine the role of executive control in fine motor sequencing using a motor-cognitive dual-task paradigm. Younger and older adults performed a sequential tapping task separately and concurrently with a semantic judgment task (Experiment 1) and a mental arithmetic task (Experiment 2). Experiment 1 established that under low cognitive load, older adults were slower and less accurate in sequential tapping than younger adults. Load was manipulated in Experiment 2, and across mental arithmetic difficulty levels, older adults were less accurate in sequential tapping when performing mental arithmetic than younger adults. At the highest difficulty level, both groups suffered performance costs. In line with gross motor research, these findings suggest a role for executive functions in fine motor performance in old age.