The effects of peripheral movement and flicker

Contrast sensitivity functions were obtained in the presence of temporally modulated surrouads. Sensitivity to low spatial frequencies was depressed below that found with a steady surround when the surround was either a sinusoidally flickering field or a drifting vertical square-wave grating. This effect was observed both with 1-sec presentations of 5- and 0.5-Hz counterphase flicker and with 60-msec pulsed gratings. In addition, reaction time histograms became more characteristic of sustained mechanisms in the presence of temporal modulation. The data were considered in terms of the activity of a nonlinear network of retinal subunits