Motor Dual-Task Deficits and Their Associations with Executive Function in Older Adults with Cognitive Impairments.

Age-related manual dexterity impairments may critically depend on cognitive impairments. This study examined associations between task demands, cognitive function and dexterity impairments in older adults. A total of 42 participants, 21 young (age 19-39; 12 female, 9 male) and 21 older (age 65-88; 12 female and 9 males) adults performed the Grooved Pegboard test under single-task, dual task (visuospatial and nonspatial tasks) and bilateral (finger-tapping test) conditions. Cognitive and executive function were assessed with the Montreal Cognitive Assessment (MoCA) and Trail Making Test (TMT). Older adults showed uniform declines in Grooved Pegboard performance across secondary tasks compared to young adults. Older adults with cognitive deficits (MoCA < 26) took 34% longer to complete the Grooved Pegboard during the nonspatial task compared to healthy older adults. The bilateral task revealed Grooved Pegboard and finger tapping impairments in older adults, particularly those with cognitive deficits, relative to young adults. Significant correlations between increased TMT B completion time and decreased Grooved Pegboard (r = 0.732) and finger-tapping (r = -0.663) performance highlights a relationship between executive function and dexterity impairments in older adults with cognitive deficits. Results suggest the role of cognitive impairments in motor function and the use of task-specific motor assessments.