What is salient in binocular rivalry
Fumihiko Taya* and Ken Mogi**,
*Department of Physiology1, Osaka University Medical School
**Sony Computer Science Laboratory
Abstract
• We studied what stimulus features count as salient in binocular rivalry.
• We found that motion is very salient and is a determining factor in the ocular dominance pattern in binocular rivalry.
• We arrive at a model of binocular rivalry involving three layers.
Neural correlates with the ocular dominance pattern in binocular rivalry
• Logothetis et al., 1989
• Leopold et al., 1996
• Kovacs et al., 1996
• Sheinberg et al., 1997
• Tononi et al., 1997
• Fries et al., 1997
• Lumer et al., 1998
Studies on binocular rivalry
• Studies on binocular rivalry has been conducted in an “all-or-none” paradigm, neglecting the spatial heterogeneity of the dominance pattern.
• Here, we investigate the spatio-temporal structure of ocular dominance pattern in binocular rivalry.
Method(1/2)
Phase difference
Left eye Right eye
Visual awareness
Fixation pointIndicator
Methods (2/2)• Stimulus we used were:
– Circles moving at a speed of 2.2 degrees/s
– Stationary circles
• We presented rivalrous images to each eyes (visual angle 11 degrees) with Crystal Eyes (StereoGraphics Corporation, Washington D.C., US).
• Monitor: FlexScan E67T (Eizo) at 150 frames/s.
Visual awareness in binocular rivalry• Both of the moving circles were always
present in visual awareness– Down to 0.3 degrees per second– Up to 20 degrees per second
• Sometimes one or both of the stationary circles disappeared from visual awareness
Change of visual awareness:moving circles
Time
Change of visual awareness:stationary circles
Average number of circles seen in the moving and stationary conditions
0
0.5
1
1.5
2
2.5
Subject FT Subject KM Moving ConditionAverage number of circles seen at any given
instant
Quantitative Analysis
• Subjects were requested to report the perceived color at the position of an indicator which flashed in several position on the screen.
Results: 180 degrees
Results: 72 degrees
Results: 0 degrees
Results: left eye
Results: right eye
Summary of results
• The spatio-temporal dominance pattern was strongly influenced by the presence of moving circles.
• The visual system behaves as dynamical adaptive system to represent the salient features at any given psychological moment.
MethodLeft eye Right eye
Visual awareness
Fixation pointIndicator
Results: the effective range of moving circles
Results
• The effective range of moving circle was about 2.2 degrees, namely the effect of salient features remained for about 1 second.
• The salient feature only had effect on the subsequent visual awareness.
• The prediction had no effect on determining the ocular dominance pattern.
Change of visual awareness:Interactive operation
Time
Result: move circles voluntarily
Three phenomenological layers
Attention
Salient features
Visual qualia
Visual Awareness
Conclusion