Lingual vibrotactile magnitude estimation and cross-modality matching: Aging effects

Lingual vibrotactile suprathreshold sensation magnitudes were investigated across four age groups (mean ages = 7.8, 19.3, 45.2, and 57.0 years) by employing the psychophysical methods of magnitude estimation and cross-modality matching. Lingual vibrotactile stimuli were presented in combination with auditory stimuli for the cross-modality 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-modality 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-modality 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. In summary, age-related response differences did occur at suprathreshold levels of vibrotactile stimulation, and the psychophysical techniques employed appeared to be a noninvasive way to make judgments about suprathreshold functioning of the human tactile system as it changes with age.