Inhibitory Processes Relate Differently to Balance/Reaction Time Dual Tasks in Young and Older Adults

ABSTRACT

Inhibitory processes have been suggested to be involved in maintaining balance in older adults, specifically in the integration of sensory information. This study investigated the association between inhibition and the ability to shift attention between auditory and visual modalities during a balance challenge. Young (21–35 years; n = 24) and older (70–85 years; n = 22) healthy subjects completed tasks assessing perceptual inhibition and motor inhibition. Subjects then performed dual-task paradigms pairing auditory and visual choice reaction time tasks with different postural conditions. Sensory channel switch cost was quantified as the difference between visual and auditory reaction times. Results showed that better perceptual and motor inhibition capabilities were associated with less sensory switch cost in the old (perceptual inhibition: r = .51; motor inhibition: r = .48). In the young, neither perceptual nor motor inhibition was associated with sensory switch cost. Inhibitory skills appear particularly important in the elderly for processing events from multiple sensory channels while maintaining balance.

Keywords:

• Balance
• Inhibition
• Dual-task
• Posturography
• Aging

ACKNOWLEDGEMENTS

Source of Research Support: (David N. Mendelson) National Institute on Aging, T32 grant AG021885, R01-AG14116. I am indebted to Dr Stephanie Studenski for providing the funding that allowed me to work in Dr Jennings' lab on this study. Source of Research Support: (Mark S. Redfern) Pittsburgh Claude D. Pepper Older Americans Independence Center, P30AG024827.