Age differences in tactile pattern recognition at the fingertip.
Young (21-26 years, n=20) and old (55-86 years, n=25) participants were tested for their ability to recognize raised letters (6-mm high, 1-mm relief) by touch. Spatial resolution thresholds were also measured with grating domes to derive an index of the degree of afferent innervation at the fingertip. Letter recognition in the young group was very consistent and highly accurate (mean, 86% correct), contrasting with the performance of the old group, which was more variable and comparatively low in accuracy (mean, 53% correct). In both groups, spatial resolution thresholds accounted for a substantial portion of the variance in the performance, suggesting a strong link between age-dependent variations in tactile innervation and recognition accuracy. The patterns of errors in the old group showed that an inability to encode internal elements specific to certain letters was at the source of most confusion among letters. Whether this inability reflected only deficient peripheral encoding mechanisms or some other alterations at the central level is discussed.
Manning
Hélène
H
Faculty of Health Sciences, School of Rehabilitation Sciences, University of Ottawa, Ontario, Canada.
Tremblay
François
F
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D005385:Fingers / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D012867:Skin / Q000294:innervation; D013236:Stereognosis / Q000502:physiology*