Red–green and achromatic temporal filters: A ratio model predicts contrast-dependent speed perception

Abstract

We simultaneously measured detection and identification performance by using isoluminant red–green (RG) and achromatic flickering stimuli and fitted these data with a modified line-element model that does not make high-threshold assumptions. The modeling shows that detection and identification data are adequately described by postulating only two underlying temporal filters each for RG and achromatic vision, even when more than two threshold classifications are evident. We use a spatial frequency of 1.5 cycles per degree (c/deg) and compare the derived temporal impulse response functions with those obtained previously with the use of 0.25- c/deg stimuli under otherwise identical conditions [..