Changes with Age and with Exclusion of Vision in Performance at an Aiming Task

Abstract

Forty industrial workers between 20 and 60 years of age took part in the experiment. Each sat facing a display in an enclosure. His task was to locate targets with a pointer, under two conditons: when he was able to make whatever use he chose of direct vision, and wearing a pair of red goggles through which only the diplay could be seen.

On the average, those over 40 years of age took more time than younger subjects over those portions of the task which were concerned with the initiation of a fresh action. When unable to make use of vision the older had far greater difficulty in locating the targets and attempted to supplement tactile and kinesthetic cues by making postural adjustments, turning their heads and often their bodies in the direction of the target at which they were aiming. These findings are discussed in relation to an earlier observation of the greater tendency for older people to look at what they are doing.