title: Why does older adults' balance become less stable when walking and performing a secondary task? Examination of attentional switching abilities.
abstract: Previous research using dual-task paradigms indicates balance-impaired older adults (BIOAs) are less able to flexibly shift attentional focus between a cognitive and motor task than healthy older adults (HOA). Shifting attention is a component of executive function. Task switch tests assess executive attention function. This multivariate study asked if BIOAs demonstrate greater task switching deficits than HOAs. A group of 39 HOA (65-80 years) and BIOA (65-87 years) subjects performed a visuo-spatial task switch. A sub-group of subjects performed a dual-task obstacle avoidance paradigm. All participants completed the Berg Balance Scale (BBS) and Timed Up and Go (TUG). We assessed differences by group for: (1) visuo-spatial task switch reaction times (switch/no-switch), and performance on the BBS and TUG. Our balance groups differed significantly on BBS score (p<.001) and switch reaction time (p=.032), but not the TUG. This confirmed our hypothesis that neuromuscular and executive attention function differs between these two groups. For our BIOA sub-group, gait velocity correlated negatively with performance on the switch condition (p=.036). This suggests that BIOA efficiency of attentional allocation in dual task settings should be further explored.
authors.affiliation: Motor Control & Cognition Laboratory, Department of Human Physiology, University of Oregon, USA. thawkes@uoregon.edu
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Hawkes
authors.forename: Ka-Chun
authors.initials: KC
authors.lastname: Siu
authors.forename: Patima
authors.initials: P
authors.lastname: Silsupadol
authors.forename: Marjorie H
authors.initials: MH
authors.lastname: Woollacott
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011597:Psychomotor Performance; D016138:Walking / Q000502:physiology*