Differential effects of a visuospatial attention task on measures of postural control in young and older adults.

The purpose of this study was to examine the influence of a visuospatial attention task on three measures of postural control in young and older adults. 20 young (19-36  years) and 20 older (67-91 years) adults performed a choice stepping response time (CSRT) task, a submaximal dorsiflexion force steadiness task, and quiet standing in 3 bilateral stances. All tasks were performed with and without a visuospatial (VS) attention task that involved visualizing a star moving within a 2 × 2 grid. CSRT increased with the addition of the VS task in both groups (p  < .001), with a larger increase for older adults than young adults (p < .001). Older adults were less steady while performing the dorsiflexion task with the VS task (p  < .001), while the VS task did not influence steadiness in young adults (p = .235). Performance during quiet standing was not influenced by the VS task in any stance (p  > .084). The findings suggest that visuospatial attention differentially affects postural control in young and older adults and the effect is task-specific. These findings suggest the need to include stepping and force control tasks to further determine what role visuospatial attention plays in postural control.