Effects of Cognition on Visual Attention and Gait in Older Adults

One in 3 adults over 65 years fall annually, resulting in costs of $34 billion in 2013. Our purpose was to investigate the effect of cognitive load on visual attention and subsequent gait quality in this population. We hypothesize that visual attention deficits, due to increased cognitive demands, impair gait in older adults. Fourteen healthy older adults (70-91 years) and 10 younger adults (18-28 years) performed three randomly assigned tasks including a modified Timed Up and Go (mTUG; participants stood up from a chair, walked 4.7 meters around a cone, and returned to a seated position); a cognitive task (subtracted 7s from a given number as quickly and accurately as possible), and these two tasks combined. If participants gazed less at critical visual cues (i.e., cone and chair) during the dual task than when walking alone, we would conclude that cognitive load negatively affected visual attention. We tracked eye movements (Mobile Eye-XG, ASL) to identify the focus of visuospatial attention, and recorded walking characteristics using a pressure-sensing mat (GAITRite). Dependent measures included cognitive performance (rate and accuracy of subtraction task), visuospatial attention (fixation time on targets), and gait parameters. Gait baselines between ages differed. However the ‘cost’ of cognitive load was similar between age groups. Stride length, velocity, and cadence decreased, while walk time and double stance time lengthened, with increased cognitive load. Gaze time on target was significantly different between tasks for younger adults, but not older adults. Our results suggest that deficits in visuospatial attention do not completely explain gait changes in older adults, although older adults with the poorest cognitive performance had the greatest impairments in walk times and visuospatial attention. Thus, fall prevention programs should consider addressing cognitive status to optimize effectiveness