FREQUENCY-DOMAIN MEASUREMENT OF VIBROTACTILE DRIVING RESPONSES IN FIRST-ORDER EFFERENT POPULATIONS

Surface recordings made at the wrist during moderate vibrotactile stim ulation of a digit display rhythmic activity at the frequency of the d riving stimulus. This activity is abolished by local anesthesia of the stimulated digit and by substitution of the corresponding digit of th e opposite hand with the recording geometry and the load on the stimul ator unchanged. Several additional features of the response are simila rly incompatible with an artifactual origin in properties of the stimu lus motion or the associated electromagnetic field, but consistent wit h previous neurophysiological observations. The frequency-domain analy sis extends readily to the single-trial level, making the technique po tentially useful for a variety of basic research and clinical purposes .