Isolated-checks were luminance-modulated temporally to elicit VEPs. Bright or dark checks were used to drive ON or OFF pathways, and low or high-contrast conditions were used to emphasize activity from magnocellular or parvocellular pathways. Manipulation of stimulus parameters and frequency analysis of the VEP were performed to obtain spatial and contrast-response functions. A biophysical explanation is offered for why the opposite polarity stimuli drive selectively ON and OFF pathways in primary visual cortex, and a lumped biophysical model is proposed to quantify the data and characterize changes in the dynamics of the system with contrast given a limited number of parameters. Response functions were found to match the characteristics of the targeted pathways. © 2006 Elsevier Ltd. All rights reserved.
Zemon, V., & Gordon, J. (2006). Luminance-contrast mechanisms in humans: Visual evoked potentials and a nonlinear model. Vision Research, 46(24), 4163–4180. https://doi.org/10.1016/j.visres.2006.07.007