Ronald T. Verrillo Institute for Sensory Research Syracuse University
The study of cutaneous sensitivity has always received less attention than have the visual and auditory systems. The reason for this is not clear, but it may be related to the fact that the sensory deficits of cutaneous tissue do not have the dramatic impact of blindness and deafness. Because touch and hearing are both mechanoreceptive sensory systems, it is not surprising that many of the basic concepts in taction are extensions of ideas that have their origins in the field of audition. And because the skin is a very large, in fact the largest, and easily accessible receptor surface, investigators have used it as a convenient surrogate for the cochlea or retina in their research. Its potential as a substitute channel of communication in the absence of sight or hearing has contributed heavily to an interest in its functional characteristics.
The vibrotactile laboratory at the Institute for Sensory Research was a direct outgrowth of ongoing auditory research at that institution. The equipment required only that a mechanical shaker replace the earphone, auditory thresholds were available for comparison, equal-loudness contours had been determined for hearing but not for vibrotaction, and the systematic study of subjective magnitude by ratio scaling was already in full swing in auditory labs throughout the world. Although the investigation of touch still receives comparatively little support, we have made significant progress since Frank Geldard ( 1970) voiced the hope that "we are not forever committed to documenting perceptual mediocrity" (p. 15). We now have accepted methods for determining detection thresholds, contours