Perception of Touch May Decline with Age - Brief Article

USA Today (Society for the Advancement of Education), June, 2000

While scientists have documented many age-related changes, little has been done to examine what happens to people's sense of touch as they grow older. A team of researchers from the University of Connecticut, Storrs, examined dynamic touch--which is involved when an object is grasped firmly and then swung or wielded--in elderly volunteers by testing their ability to perceive a tennis racket's "sweet spot." That is defined as the point on the racket at which contact with a ball would produce the best results.

In the first of two experiments, eight volunteers, aged 62-89, who were not recreational tennis players were seated at a desk. Each had a tennis racket placed in his or her right hand. With their hands and the rackets obscured by a curtain, the volunteers were asked to indicate the length of the racket and the spot on the racket at which they would like to hit a ball. For each of six different-sized rackets, the participants were within four inches of the actual sweet spot and six inches of the actual lengths. The results are comparable to those obtained with younger participants.

In the second experiment, eight volunteers between the ages of 63 and 79 were asked to perceive the length and sweet spot of a rod with a metal ring attached to it. The purpose of attaching the ring was to manipulate the mass distribution without altering the object's actual mass and length. As in the first experiment, the volunteers indicated the characteristics while they held the hidden object.

According to the study's findings, the rod's perceived length depended on whether the ring was attached near the participant's hand or far away from it. Perception of the sweet spot closely tracked the actual sweet spot. Given the similar results for both experiments, it is apparent that, just as for the young, the elderly's perception is constrained by the moments of the objects' mass distribution.

Performance by the two groups is not identical, however, researchers discovered. The elderly's perception of the object's length tended to be smaller than the young people's. The difference in perception, which grows as the objects increase in size, may be due to age-related declines in muscle strength, psychology professor Claudia Carello and her colleagues conjecture. If the elderly felt they couldn't control an object when it was fully extended, their report of how far they could reach or strike with it tended to be correspondingly shorter.