Reflex modification: A method for assessing cutaneous dysfunction
- Cite this article as:
- Ison, J.R., Foss, J.A., Falcone, P. et al. Perception & Psychophysics (1986) 40: 164. doi:10.3758/BF03203012
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A brief and innocuous electrocutaneous stimulus applied to the lip or to the fingers altered the amplitude of reflexive eyeblinks elicited by a more intense stimulus to the forehead. The effectiveness of the initial stimulus was determined by its lead time—increasing to a maximum and then declining with an increase in the interval between the two stimuli—and by its intensity—steadily increasing with an increase in stimulus voltage. At both sites, lip and fingers, the intensities of the stimuli that approximated the sensory detection threshold (determined by a conventional method of limits) had reliable inhibitory effects on the response to the subsequent eliciting stimulus. The sensitivity of the reflex modification process to relatively weak stimuli suggested the potential value of these procedures for the objective evaluation of cutaneous loss and paresthesia. An example is provided in the history of a case in which two of three fingers that had been amputated were replanted. Ten weeks later, a test revealed that stimulation delivered to an injured finger had lost the inhibitory control it normally exerts on an intact finger.