Why does older adults' balance become less stable when walking and performing a secondary task? Examination of attentional switching abilities

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.

► Balance-impaired elders shift attention during dual-tasks less efficiently than healthy elders. ► Shifting attention is a component of executive attention function. ► We compared the performance of balance-impaired and healthy elders on a task switch test. ► Compared to healthy elders balance-impaired elders demonstrated deficits in task switch ability. ► The relationship between switch ability and gait should be further investigated in the elderly.