Gaze behavior of young and older adults during stair walking.

The authors quantitatively described gaze behavior of young (n = 10) and older (n = 10) adults during stair negotiation, which is information that is crucial for understanding the underlying visuomotor control of stair walking and the effects of aging on this control. Both age groups spent the majority of time looking at central aspects of the stairs approximately 3 steps ahead. Older adults showed less variability in the extent to which they looked ahead (p < .05), and all participants fixated the stairs for briefer periods during descent as opposed to ascent (p < .001). Older adults fixated stairs significantly longer than did young adults before stepping onto the stairs (p < .05). The authors conclude that adults need central visual information describing future stepping locations and that there are age-related differences in visual sampling that reflect changes in the visuomotor control processes subserving locomotion.