Mechanisms underlying global stereopsis in fovea and periphery. 2013

Nirel Witz, and Robert F Hess
McGill Vision Research, Dept. Ophthalmology, McGill University, Montreal, Quebec, Canada.

To better understand the pooling properties underlying global stereopsis we examined the relationship between carrier luminance spatial frequency and modulator disparity spatial frequency. Thresholds for detecting global sinusoidal disparity corrugations of spatially band-pass noise were measured as a function of modulator disparity spatial frequency for both centrally and peripherally located stimuli using a standard 2-IFC task. We found a characteristic relationship that depended on modulator disparity spatial frequency. At high modulator disparity spatial frequencies (>1c/d), there is an optimal ratio of around 2.6, whereas at low modulator disparity spatial frequencies, there is an optimal absolute carrier luminance spatial frequency (i.e., 3c/d). In the periphery, vision is restricted to modulator disparity spatial frequencies below 1c/d and, as a consequence, following the above rule, there is an optimum absolute carrier luminance spatial frequency that reduces in spatial frequency with increasing eccentricity. This finding is consistent with there being more than one channel processing global stereo that is subsequently confirmed using a 2×2 AFC detection/discrimination paradigm. Furthermore, because of the different carrier/modulator relationships in central and peripheral vision, peripheral global stereo cannot be simply related to central global stereo by a scaling factor and thus cannot be simply due to cortical magnification, as originally thought.

UI MeSH Term Description Entries
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
D003867 Depth Perception Perception of three-dimensionality. Stereopsis,Stereoscopic Vision,Depth Perceptions,Perception, Depth,Perceptions, Depth,Stereopses,Stereoscopic Visions,Vision, Stereoscopic,Visions, Stereoscopic
D004192 Discrimination, Psychological Differential response to different stimuli. Discrimination, Psychology,Psychological Discrimination
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
D014794 Visual Fields The total area or space visible in a person's peripheral vision with the eye looking straightforward. Field, Visual,Fields, Visual,Visual Field

Related Publications

Nirel Witz, and Robert F Hess
January 1978, Vision research,
Nirel Witz, and Robert F Hess
September 2000, Journal of the Optical Society of America. A, Optics, image science, and vision,
Nirel Witz, and Robert F Hess
January 1991, Neuropsychologia,
Nirel Witz, and Robert F Hess
December 1974, Vision research,
Nirel Witz, and Robert F Hess
October 1985, Journal of the Optical Society of America. A, Optics and image science,
Nirel Witz, and Robert F Hess
May 1997, Proceedings of the National Academy of Sciences of the United States of America,
Nirel Witz, and Robert F Hess
January 1979, Vision research,
Nirel Witz, and Robert F Hess
April 1994, Journal of the Optical Society of America. A, Optics, image science, and vision,
Nirel Witz, and Robert F Hess
October 2006, Vision research,
Copied contents to your clipboard!