title: Psychophysical and physiological responses to gratings with luminance and chromatic components of different spatial frequencies.
abstract: Gratings that contain luminance and chromatic components of different spatial frequencies were used to study the segregation of signals in luminance and chromatic pathways. Psychophysical detection and discrimination thresholds to these compound gratings, with luminance and chromatic components of the one either half or double the spatial frequency of the other, were measured in human observers. Spatial frequency tuning curves for detection of compound gratings followed the envelope of those for luminance and chromatic gratings. Different grating types were discriminable at detection threshold. Fourier analysis of physiological responses of macaque retinal ganglion cells to compound waveforms showed chromatic information to be restricted to the parvocellular pathway and luminance information to the magnocellular pathway. Taken together, the human psychophysical and macaque physiological data support the strict segregation of luminance and chromatic information in independent channels, with the magnocellular and parvocellular pathways, respectively, serving as likely the physiological substrates.
authors.affiliation: Graduate Center for Vision Research, SUNY College of Optometry, 33 West 42nd St., New York, New York 10036, USA. bcooper@sunyopt.edu
authors.forename: Bonnie
authors.initials: B
authors.lastname: Cooper
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Barry B
authors.initials: BB
authors.lastname: Lee
mesh_terms: D000818:Animals; D003116:Color; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008251:Macaca; D008297:Male; D010775:Photic Stimulation; D011601:Psychophysics; D012165:Retinal Ganglion Cells / Q000166:cytology; D012684:Sensory Thresholds / Q000502:physiology; D013028:Space Perception / Q000502:physiology*