Walking down memory lane: where walkers look as they descend stairs provides hints about how they control their walking behavior.

Walking down stairs is a challenging perceptual-motor activity, as indicated by the large number of documented falls on stairs each year. The present study suggests that descending stairs is also a challenging memorial activity. A total of 147 people were videotaped as they descended a staircase. When the walkers were in the middle of the stairs, they looked down every third step on average, but as they neared the bottom, they looked down with high probability on or around the fourth step. The trigger for the last look down, by hypothesis, was disappearance of the stairs from the lower visual field. A model is proposed in which mid-stair walking is controlled primarily on the basis of visual guidance, whereas end-stair walking is controlled primarily on the basis of memory.