EVALUATING AGE DIFFERENCES IN THE SHORT-TERM AND LONG-TERM MEMORY PROCESSES UNDERLYING MOTOR LEARNING

Author

Alexandra T. Watral, Michigan Technological UniversityFollow

Date of Award

2023

Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy in Applied Cognitive Science and Human Factors (PhD)

Administrative Home Department

Department of Cognitive and Learning Sciences

Advisor 1

Kevin Trewartha

Committee Member 1

Shane Mueller

Committee Member 2

Erich Petushek

Committee Member 3

Rajiv Ranganathan

Abstract

Motor learning involves improving the proficiency of a novel skill through the repetition of movement. The early stages of motor learning rely on explicit memory – a cognitive function known to be impacted by Alzheimer’s disease (AD). Recent research has shown that motor behavior, especially complex motor tasks, may be impaired in mild cognitive impairment and AD. However, little is known about how motor learning may decline in AD or whether it could aid in diagnostic clarity early in disease progression. The overall goal of this dissertation was to examine the acquisition and long-term retention of motor learning tasks in individuals experiencing healthy aging and identify new motor behavioral markers sensitive to cognitive impairments in the earliest stages of Alzheimer’s disease. Our first study explored age differences in acquisition and retention between younger and older adults on a force field adaptation task, while our second study explored acquisition and retention differences on a self-report visuomotor rotation task. Healthy younger and older adults completed the prescribed motor learning task on two days, with testing sessions occurring 24 hours apart. Older adults also completed a standard neuropsychological battery used to diagnose Alzheimer’s disease. These studies revealed age differences in long-term task retention despite the lack of differences in initial acquisition and short-term retention. In both tasks, younger adults appeared to retain more information from Day 1 to Day 2 than older adults. Scores from the neuropsychological battery associated with overall cognitive functioning were correlated with long-term retention performance measures. Our third study examined force-field adaptation performance differences between healthy older adults and those experiencing Alzheimer’s-like cognitive impairment. We further examined whether retention measures from the force field adaptation task could improve our ability to discriminate between healthy aging and cognitive impairments beyond standard neuropsychological test scores. Again, participants completed the force field adaptation task on two days, with testing occurring 24 hours apart. Both groups also completed a standard diagnostic neuropsychological battery. We found that healthy older adults retained more information from Day 1 to Day 2 than those with cognitive impairment, and a retention measure from the force field adaptation task increased group discriminability when used alongside neuropsychological scores. Overall, this work shows that age-related changes in long-term memory contribute to differences in motor skill task retention, and these changes are exacerbated by Alzheimer’s-like cognitive impairment. Measuring long-term retention of motor skill learning may provide a behavioral measure that can improve the reliability of neuropsychological test batteries to the earliest stages of dementia.

Recommended Citation

Watral, Alexandra T., "EVALUATING AGE DIFFERENCES IN THE SHORT-TERM AND LONG-TERM MEMORY PROCESSES UNDERLYING MOTOR LEARNING", Campus Access Dissertation, Michigan Technological University, 2023.

https://doi.org/10.37099/mtu.dc.etdr/1632