Neurophysiological interpretation of human visual reaction times: effect of contrast, spatial frequency and luminance

The effect of target contrast on the attentional blink

“…Pooled across the relevant experiments, 10 the correlation (r) between T1 performance and T1-distractor relative contrast was .84 ( p Ͻ .001). These results either replicate or are consistent with those in the psychophysical literature (Ejima & Otani, 1987;Gish et al, 1986;Lupp et al, 1976;Murray & Plainis, 2003;Plainis & Murray, 2000;Tiipana, Paramei, & Alshuth, 2001). …”

“…Detection and identification performance is a monotonically increasing function of contrast (Graham, 1989). Reaction time to a spatial pattern decreases as its contrast increases (Ejima & Ohtani, 1987;Gish, Shulman, Sheehy, & Leibowitz, 1986;Lupp, Hauske, & Wolf, 1976;Murray & Plainis, 2003;Plainis & Murray, 2000;Thompson & Drasdo, 1989), implying that increases in contrast allow faster information accumulation and/or improve processing efficiency. The neurophysiological evidence accords well with the psychophysical data.…”

Postreceptoral chromatic-adaptation mechanisms in the red-green and blue-yellow systems using simple reaction times

“…Then, mean VRTs were fitted for each LϪM-and S-cone axis according to a modified Piéron function: 22,47 …”

“…(2) was fitted under each adapting stimulus using the common fitting procedure in terms of reciprocal RMS cone contrast 22,47 , as well as a nonlinear leastsquares method 19,21 [L − M axis: RG1, RG2, and RG3…”

Clinical Psychophysical Assessment of the ON- and OFF-Systems of the Magnocellular and Parvocellular Visual Pathways

“…The electrophysiological demonstrations for a separate activity of MC and PC pathways in humans were obtained by varying the spatial frequencies and the time of stimuli presentation [10]. The differential properties of the MC and PC pathways make it possible to infer the relative role of those pathways in the capacity to discriminate contrast levels at different spatial patterns, usually evaluated by the contrast sensitivity function measurement.…”