Binocular rivalry with isoluminant stimuli visible only via short-wavelength-sensitive cones

O'Shea, R.P. and Williams, D.R. (1996) Binocular rivalry with isoluminant stimuli visible only via short-wavelength-sensitive cones. Vision Research, 36 (11). pp. 1561-1571.

Abstract

To test whether the binocular contour rivalry mechanism is tritanopic, we presented isoluminant, rival stimuli visible only via the short-wavelength-sensitive (S) cones. We stimulated only the S cones with violet gratings superimposed on a bright yellow field that adapted the responses of the middle- and long-wavelength-sensitive (M and L) cones. We found that an S cone grating presented to one eye rivalled with an orthogonal grating presented to the other. Rivalry persisted over a range of luminances and contrasts of the S-cone stimuli, and was greater than could be accounted for by nonrival fading. The spatial spread of rivalry from S-cone stimuli is similar to that for the same stimuli when visible also to the M and L cones (luminance stimuli). We found that an S-cone stimulus would rival with a luminance stimulus, and exploited this to determine the equivalent luminance contrast of S-cone stimuli by putting them in a rivalry competition with luminance stimuli. For rivalry, the equivalent luminance contrast of isoluminant, S-cone stimuli is much less than their S-cone contrast. The existence of rivalry with isoluminant stimuli, along:with earlier evidence that such stimuli can support stereopsis, challenges the view that an achromatic channel alone drives certain higher level functions such as depth perception.

Item Type:	Journal Article
Murdoch Affiliation(s):	School of Psychology and Exercise Science
Publisher:	Elsevier Ltd
Copyright:	© 1996 Elsevier Science Ltd.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/31361

Item Control Page