Rapid Visual Assessment from Evoked Potentials: An Alternative to Computer Averaging

Computer averaging of the visual evoked potential, either transient or steady state, retrieves the actual waveshape of discrete evoked responses. The retrieval process is based on building up the response through superimposition (Regan, 1972). Obviously it must be assumed that the many weak responses being summed together are identical. This assumption works well in practice, although in fact there are amplitude and w waveshape variations (Childers, Doyle, Brinck and Perry, 19727 general critique in Aunon, McGillem & Childers, 1981) for which sophisticated signal processing solutions are available (Senmoto and Childers, 1972). Particularly for late components, one should be circumspect in viewing the output of an averager as a picture of the true and only possible evoked potential waveform.