Temporal detection in human vision: dependence on stimulus energy.
We have previously proposed and evaluated an economical model of human performance in tasks requiring spatiotemporal signal detection in spatiotemporal noise [Vision Research (to be published)]. The model was successful in describing human psychophysical performance and provides a means for comparing temporal filters (mechanisms) employed under different stimulus conditions. We present investigations into how estimates of temporal mechanisms depend on the contrast energy of the stimulus. Temporal-sensitivity changes result in covariation of the cutoff and peak frequencies of the low-pass and bandpass mechanisms, respectively, with stimulus energy. The results indicate that sensitivity to high temporal frequencies increases as stimulus energy increases, commensurate with extent physiological evidence in cat and primate.
Fredericksen
R E
RE
McGill Vision Research, Montreal, Quebec, Canada. eric@mach2.hipl.uci.edu
Hess
R F
RF
D006801:Humans; D008163:Luminescent Measurements; D008954:Models, Biological; D010470:Perceptual Masking; D010775:Photic Stimulation / Q000379:methods*; D011601:Psychophysics; D013998:Time Perception / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*