Length perception by dynamic touch: The effects of aging and experience

Two experiments investigated the effects of age and experience on length perception. A total of 46 participants were asked to wield and estimate the length of unseen rods by adjusting a movable board to equal their estimate of the reachable distance of the rod. The results demonstrated that (a) participants used the haptic subsystem of dynamic touch to perceive dissimilarities in object length and (b) experience playing racquet sports was more influential than the effect of age in perceptual judgments regarding object length. The results are discussed in the context of the ecological approach to haptic perception. Key Words: Dynamic touch—Length perception—Experience—Aging—Ecological perspective. WE PICK up objects and wield them. We pick up scissorsand cut paper, we pick up sticks and rub them together to make a fire, we pick up a racquet and swing it. Objects are material things, having mass, and mass resists our efforts to displace it. This resistance generates pressure on the hand, pressure that influences the stimulation of receptors in the skin, muscles, and tendons. For this reason, the act of wielding can provide an impression of the spatial dimensions of the object. This type of perception is known as dynamic touch (Gibson