PURPOSE To investigate the spatial frequency selectivity of the human motion system by using the technique of visual masking. METHODS Modulation-depth thresholds for identifying the direction of a sinusoidal test pattern were measured over a range of spatial frequencies (0.25-4 cyc/deg) in the absence and presence of a temporally jittering mask. RESULTS At the lowest test frequency (0.25 cy...

Octave masking was investigated at four different frequencies (250, 500, 1000, and 2000 Hz) as a function of intensity of the masker and phase of the test signal. Slopes of phase-locked octave masking were found to increase with masking signal frequency, from 0.80 dB/dB at 250 Hz to 3.0 dB/dB at 2000 Hz. The monaural octave-masking phase effect was considerably larger for masking signals at low...

Binocular contrast interactions in human vision were studied psychophysically. Thresholds were obtained for sinewave grating stimulation of the right eye in the presence of simultaneous masking gratings presented to the right eye (monocular masking) or left eye (dichoptic masking). In the first experiment, thresholds were measured at 0.25, 1.0, 4.0, and 16.0 cycle per degree (cpd) as a function...