Effects of Aging on Responses to Suprathreshold Lingual Vibrotactile Stimulation

Lingual vibrotactile suprathreshold sensation magnitudes were investigated across four age groups ( M ages = 7.8 yr., 193 yr., 45.2 yr., and 57.0 yr, age range = 5 to 64 yr.) by employing the psychophysical methods of magnitude estimation and cross-modal matching. Lingual vibrotactile stimuli were presented in combination with auditory stimuli for the cross-modal matching task. For lingual vibrotactile magnitude estimation, both the upper and lower power functions were steeper for the oldest age group. The power functions for cross-modal matching in which the vibratory stimulus was the standard showed asymptotic growth at about 25-dB sensation level for the three older age groups, but not for the youngest age group. Straight-line power functions were obtained for all age groups on the cross-modal matching task when the auditory stimulus was the standard, with the older aged subjects making larger lingual vibrotactile magnitude adjustments to the lower level auditory stimuli than the younger aged subjects. These results are discussed in relation to neurophysiological and behavioral changes which occur during development and aging.