Nociceptive evoked potentials revisited in the frequency domain

Human somatosensory evoked potentials (SEP), especially those evoked by electrical stimulation of toothpulp and teeth or by laser thermal stimulation of skin, have attracted biomedical attention since 1975 as possible indicators of the quantity of acute pain being perceived by the subject. The dental variety has been claimed as an "objective correlate of acute laboratory pain." But investigators of SEP for mechanical, electrical, and thermal stimulation of skin and mucocutaneous junctions have provided data which seriously question the meaning of that claim. Most recently dental SEP workers have rediscovered some well-known ambiguities in their own data, all of which refer only to time-domain or transient characteristics of event related brain potentials (ERBP). Perhaps we should reconsider an older approach to understanding ERBP, using concurrent analysis of their transient temporal and steady-state frequency characteristics.