Aging and Inhibition of a Prepotent Motor Response during an Ongoing Action

ABSTRACT

Inhibitory functions are key mechanisms underlying age related decline (Park & Gutchess, 2000, in: Cognitive aging: A primer. Hove: Psychology Press), yet few studies have investigated their impact on everyday tasks involving action as well as cognition. Using an everyday-based go/no-go task we devised a motor analogy of traditional neuropsychological tests to investigate in 134 older (aged 60–88) and 133 younger adults (aged 20–59) the ability to inhibit a prepotent motor response during an ongoing action. Older adults produced more inhibition failures as expected, but more strikingly inhibitory errors were not all or none; even when the inappropriate response was successfully inhibited, difficulties controlling ongoing movements emerged from as young as people in their 40s. The ability to inhibit therefore does not ensure control of ongoing tasks, and traditional cognitive tests may be unable to detect such difficulties. Furthermore, performance did not covary with education or action speed. Implications for neuropsychological theory and assessing/enhancing functional ability are discussed.

This study was funded by the EPSRC as part of a large-scale multidisciplinary project entitled “the integration of biomechanical and psychological parameters of functional performance of older adults into a new computer aided design package for inclusive design.” We thank the many older adults who kindly volunteered as participants.