Aging and the perception of a racket's sweet spot

Young adults are able to perceive an implement's center of percussion (CP) or "sweet spot," and to distinguish it from the implement's length, simply on the basis of wielding. Given the known changes in mechanoreceptors with aging, two experiments assessed these perceptual abilities in older adults (ranging in age from 62 to 89 years with an average of 69.2). They, too, distinguished length from the sweet spot simply on the basis of wielding, both for tennis rackets (Experiment 1) and for bats contrived from wooden rods with attached masses (Experiment 2). Results conformed to previous research on dynamic touch in showing that perceiving the extents of wielded objects is constrained by the moments of the objects' mass distributions. Moreover, so-called young-old plots were linear - older peoples' perceptions were predicted by younger peoples' perceptions - implicating a common underlying mechanism for the two age groups. Nonetheless, the perceived-to-actual functions were generally flatter for elderly participants. How aging might compromise the functioning of dynamic touch was discussed in terms of fractal organization and functional limitations. (C) 2000 Elsevier Science B.V. All rights reserved. PsycINFO classification: 2320; 2330; 2820.