Short latency mechanically evoked somatosensory potentials in humans

Mechanically and electrically evoked somatosensory potentials in humans: Scalp and neck distributions of short latency components

“…The sound produced by the movement of the vibrator was masked by white noise from a speaker near the subject. A more detailed account of the mechanical stimulus has been provided earlier (Pratt et al 1979a). …”

“…Recently we have described short latency mechanically evoked potentials (Pratt et al 1979a) and compared them with electrically evoked somatosensory potentials (Pratt et al 1979b). In our previous studies both of the electrodes in the differential configuration were cephalic (or nuchal) and thus the distribution of components was difficult to assess because of possible superimposition of constituents in the wave forms recorded.…”

Mechanically and electrically evoked somatosensory potentials in normal humans

“…Mechanically evoked potentials recorded by the digital electrodes were primarily an artifact of movement. 21 In contrast, potentials evoked by electrical sti.mulation at the wrist and recorded by the digital electrodes consisted of a biphasic, short-duration component (N3-P4), followed by a broader monophasic component (P9). P9 only accompanied high-intensity electrical stimulation that produced muscle twitches.…”

“…1 7-2o Recently, we described procedures for recording mechanically evoked potentials from additional levels of the somatosensory pathway. 21 In the present study we compared potentials evoked by mechanical cutaneous stimulation with potentials evoked by electrical stimulation of nerves.…”

“…Further details of the mechanical stimulus were provided elsewhere. 21 Digital nerve potentials were recorded from the ring electrodes on the digit (figure 1). The other recording electrodes were 9-mm-diameter silver cups attached to the skin by collodion glue, with resistance less than 3 kOhm.…”