Biomaterial Database

Temporal integration of the chromatic channels in peripheral vision. 2009

Osamu Masuda, and Keiji Uchikawa

Department of Information Processing, Tokyo Institute of Technology, G2-1, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan. omasuda@cvs.rochester.edu

We measured the temporal summation properties of paired flashes to investigate the temporal responses of the chromatic channel in peripheral vision in comparison with those of the luminance channel. The size of the stimulus was scaled according to the cortical magnification factor. The temporal response was biphasic to complementary-chromatic pulse pairs, and was accelerated in peripheral vision in the same way as luminance pulse pairs. On the other hand, the temporal response was monophasic to same-chromatic pulse pairs, and was decelerated in the periphery. We proposed a model of the chromatic channel in which biphasic and monophasic internal channels were arranged in parallel. The sensitivity of the biphasic channel at high temporal frequency in the periphery was comparable to that in the fovea, whereas the sensitivity of the monophasic channel at low temporal frequency in the periphery matched that in the fovea. Similar results were obtained with pairs of flashed chromatic Gabor patches with their spatial frequencies scaled according to the cortical magnification factor. The inhibition phase of the biphasic channel was degraded with the spatial carrier frequency of the Gabor patch. The properties of the biphasic channel were consistent with the double duty hypothesis, while those of the monophasic channel were consistent with the two-channel hypothesis. The biphasic channel may correspond to the parvocellular pathway and the monophasic channel may reflect the properties of the koniocellular pathway.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008959	Models, Neurological	Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Neurologic Models,Model, Neurological,Neurologic Model,Neurological Model,Neurological Models,Model, Neurologic,Models, Neurologic
D008960	Models, Psychological	Theoretical representations that simulate psychological processes and/or social processes. These include the use of mathematical equations, computers, and other electronic equipment.	Model, Mental,Model, Psychological,Models, Mental,Models, Psychologic,Psychological Models,Mental Model,Mental Models,Model, Psychologic,Psychologic Model,Psychologic Models,Psychological Model
D010775	Photic Stimulation	Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.	Stimulation, Photic,Visual Stimulation,Photic Stimulations,Stimulation, Visual,Stimulations, Photic,Stimulations, Visual,Visual Stimulations
D011601	Psychophysics	The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.	Psychophysic
D003118	Color Perception	Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.	Color Perceptions,Perception, Color,Perceptions, Color
D005584	Fovea Centralis	An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012684	Sensory Thresholds	The minimum amount of stimulus energy necessary to elicit a sensory response.	Sensory Threshold,Threshold, Sensory,Thresholds, Sensory
D013998	Time Perception	The ability to estimate periods of time lapsed or duration of time.	Temporal Perception,Temporal Processing,Time Processing,Perception, Temporal,Perception, Time,Processing, Temporal,Processing, Time