title: Evidence of Stereoscopic Surface Disambiguation in the Responses of V1 Neurons.
abstract: For the important task of binocular depth perception from complex natural-image stimuli, the neurophysiological basis for disambiguating multiple matches between the eyes across similar features has remained a long-standing problem. Recurrent interactions among binocular disparity-tuned neurons in the primary visual cortex (V1) could play a role in stereoscopic computations by altering responses to favor the most likely depth interpretation for a given image pair. Psychophysical research has shown that binocular disparity stimuli displayed in 1 region of the visual field can be extrapolated into neighboring regions that contain ambiguous depth information. We tested whether neurons in macaque V1 interact in a similar manner and found that unambiguous binocular disparity stimuli displayed in the surrounding visual fields of disparity-selective V1 neurons indeed modified their responses when either bistable stereoscopic or uniform featureless stimuli were presented within their receptive field centers. The delayed timing of the response behavior compared with the timing of classical surround suppression and multiple control experiments suggests that these modulations are carried out by slower disparity-specific recurrent connections among V1 neurons. These results provide explicit evidence that the spatial interactions that are predicted by cooperative algorithms play an important role in solving the stereo correspondence problem.
authors.affiliation: Center for the Neural Basis of Cognition and Computer Science Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.|Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Samonds
authors.affiliation: Smith-Kettlewell Brain Imaging Center, Smith-Kettlewell Eye Research Institute, San Francisco, CA 94115, USA.|Optometry and Vision Science Division, City University of London, London EC1V 0HB, UK.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Tyler
authors.affiliation: Center for the Neural Basis of Cognition and Computer Science Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
authors.forename: Tai Sing
authors.initials: TS
authors.lastname: Lee
mesh_terms: D000200:Action Potentials; D000818:Animals; D005260:Female; D008253:Macaca mulatta; D008297:Male; D008839:Microelectrodes; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D013997:Time Factors; D015357:Vision Disparity / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*
keywords: macaque; primary visual cortex; recurrent; stereoscopic; surround