SPECIFICITY AND SELECTIVITY OF CHROMATIC VISUAL-EVOKED POTENTIALS

A paper by Rabin et al. (1994) Vision Research, 34, 2657-2671, claimed that spatially extensive grating stimuli could be used to generate ch romatic-specific visual evoked potentials from subjects assumed to hav e standard spectral sensitivity and tritanopic confusion lines. Here w e demonstrate that such spatially extensive stimuli may generate respo nses which are contaminated by luminance-contrast intrusions, Such int rusions are mainly due to chromatic aberrations and are compounded by the abovementioned assumptions. Claims regarding the chromatic selecti vity of VEPs must, therefore, be substantiated by establishing correla tions with the known properties of the chromatic system. Copyright (C) 1996 Elsevier Science Ltd.