Spatial frequency tuning of facilitation by masks.
The spatial frequency tuning of facilitation by masks is derived for a 2 c/deg test grating, counterphased at 8.8 Hz, from the contrasts at which masks of different spatial frequencies facilitate maximally. This tuning function has a bandwidth at half height of roughly 1.5 octaves, much broader than has been estimated previously from tuning functions determined at a constant contrast for each mask. We show also that best facilitation more than doubles sensitivity for tests of 4 c/deg and below, and that the magnitude of the facilitation effect declines at higher spatial frequencies.
Speed
H D
HD
Department of Psychology, University of Western Australia, Nedlands.
Ross
J
J
D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D012684:Sensory Thresholds / Q000502:physiology