title: Binocular combination of second-order stimuli.
abstract: Phase information is a fundamental aspect of visual stimuli. However, the nature of the binocular combination of stimuli defined by modulations in contrast, so-called second-order stimuli, is presently not clear. To address this issue, we measured binocular combination for first- (luminance modulated) and second-order (contrast modulated) stimuli using a binocular phase combination paradigm in seven normal adults. We found that the binocular perceived phase of second-order gratings depends on the interocular signal ratio as has been previously shown for their first order counterparts; the interocular signal ratios when the two eyes were balanced was close to 1 in both first- and second-order phase combinations. However, second-order combination is more linear than previously found for first-order combination. Furthermore, binocular combination of second-order stimuli was similar regardless of whether the carriers in the two eyes were correlated, anti-correlated, or uncorrelated. This suggests that, in normal adults, the binocular phase combination of second-order stimuli occurs after the monocular extracting of the second-order modulations. The sensory balance associated with this second-order combination can be obtained from binocular phase combination measurements.
authors.affiliation: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, PR China ; McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Zhou
authors.affiliation: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, PR China.
authors.forename: Rong
authors.initials: R
authors.lastname: Liu
authors.affiliation: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, PR China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Hess
mesh_terms: D000328:Adult; D000465:Algorithms; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D010775:Photic Stimulation; D015348:Vision, Binocular / Q000502:physiology*