Cross-orientation masking is speed invariant between ocular pathways but speed dependent within them

Meese, Timothy S. and Baker, Daniel H. (2009). Cross-orientation masking is speed invariant between ocular pathways but speed dependent within them. Journal of Vision, 9 (5), 2, 1-15.

Abstract

In human (D. H. Baker, T. S. Meese, & R. J. Summers, 2007b) and in cat (B. Li, M. R. Peterson, J. K. Thompson, T. Duong, & R. D. Freeman, 2005; F. Sengpiel & V. Vorobyov, 2005) there are at least two routes to cross-orientation suppression (XOS): a broadband, non-adaptable, monocular (within-eye) pathway and a more narrowband, adaptable interocular (between the eyes) pathway. We further characterized these two routes psychophysically by measuring the weight of suppression across spatio-temporal frequency for cross-oriented pairs of superimposed flickering Gabor patches. Masking functions were normalized to unmasked detection thresholds and fitted by a two-stage model of contrast gain control (T. S. Meese, M. A. Georgeson, & D. H. Baker, 2006) that was developed to accommodate XOS. The weight of monocular suppression was a power function of the scalar quantity ‘speed’ (temporal-frequency/spatial-frequency). This weight can be expressed as the ratio of non-oriented magno- and parvo-like mechanisms, permitting a fast-acting, early locus, as befits the urgency for action associated with high retinal speeds. In contrast, dichoptic-masking functions superimposed. Overall, this (i) provides further evidence for dissociation between the two forms of XOS in humans, and (ii) indicates that the monocular and interocular varieties of XOS are space/time scale-dependent and scale-invariant, respectively. This suggests an image-processing role for interocular XOS that is tailored to natural image statistics—very different from that of the scale-dependent (speed-dependent) monocular variety.

Publication DOI: https://doi.org/10.1167/9.5.2
Divisions: Life & Health Sciences > Optometry
Life & Health Sciences
Additional Information: Creative Commons Attribution Non-Commercial No Derivatives License
Uncontrolled Keywords: human vision,psychophysics,contrast gain control,interocular masking,binocular rivalry,Ophthalmology,Sensory Systems
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://journalo ... sion.org/9/5/2/ (Publisher URL)
Published Date: 2009-05-04
Authors: Meese, Timothy S. ( 0000-0003-3744-4679)
Baker, Daniel H.

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