Effect of tourniquet-induced ischemia on magnitude scaling of tactile stimuli applied to the human hand.
The effect of tourniquet-induced ischemia was tested on magnitude scaling of supraliminal tactile stimuli (single-cycle sine waves) applied to the human hand contra- or ipsilaterally to the cuff. Magnitude estimations were not influenced on the contralateral side. In the ischemic hand there was a reduction of magnitude estimates beginning 12 min. after inflation of the cuff, independent of the stimulus intensity. The results indicate that peripheral noxious stimulation does not produce a nonsegmental reduction of tactile sensitivity. Moreover, it is suggested that the thickest afferent mechanoreceptive fibers (A-beta) have a major role in the mediation of tactile signals both at liminal and supraliminal levels.