Simulation of Cognitive Aging and Effects of Cognitive Load on Finger Sequencing Performance

and submitted in partial fulfillment of the requirements for the degree of Master of Arts (Psychology) complies with the regulations of the University and meets the accepted standards with respect to originality and quality. Abstract Simulation of Cognitive Aging and Effects of Cognitive Load on Finger Sequencing Performance Yana Korotkevich The purpose of the current study was to examine the effect of cognitive load on fine motor reprogramming using a motor-cognitive paradigm. We propose that in the face of conflict, both executive control and motor control mechanisms are involved in the process of reprogramming well-learned motor behaviours, and these two mechanisms become more interconnected with increasing age. To explore this relationship, we used a dual-task paradigm to simulate the effects of cognitive aging in young adults. To assess motor reprogramming, nineteen young adults overlearned a sequence of key presses in a practice phase of the experiment. Occasional deviations of the practiced sequence were introduced in a test phase. To manipulate cognitive load, participants performed the motor task separately and concurrently with a Serial 7s subtraction test. A 3-D motion capture system was used to parse finger movements into planning and motor execution phases. It was hypothesized that under higher divided attention demands, participants' motor responses would be slowed down, and they would lose their ability to speed up their motor execution times. When key press responses were parsed into kinematic responses, the results showed that under both attention conditions, when presented with a deviation from a learned sequence, participants spent more time planning their movements. Participants were able to speed up their execution time on the violation transitions under single-task conditions; however, they lost this ability under dual-task conditions. In line with gross motor research, these findings suggest that cognitive capacity, reduced in the case of iv older adults or young adults under divided attention conditions, influences the ability to flexibly adapt movements.