PATTERN ERGS FROM ISOLUMINANT GRATINGS - POOR SELECTIVITY COMPARED WITH VEPS

The PERGs elicited by low contrast achromatic (luminance-modulated) an d chromatic (isoluminant) gratings were studied as a function of the p resentation mode (rapid onset, offset, reversal), departure from isolu minance, contrast and spatial frequency; predominantly phasic-type res ponses were found in all cases. We propose that the PERGs for low and moderate contrast, achromatic and chromatic grating stimuli, are gener ated by non-linear, transient retinal cells of the magno-system Parvo retinal cells seem to contribute to the response only at higher chroma tic contrasts. The transient nature of the PERG obtained from isolumin ant gratings makes it doubtful that these signals represent the activi ty of colour-related processes. Copyright (C) 1997 The College of Opto metrists. Published by Elsevier Science Ltd.