Transcript What is salient in binocular rivalry?

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
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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.
Left eye
Indicator
Method(1/2)
Right eye
Fixation point
Phase difference
Visual awareness
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 at any given
instant
Average number of circles seen in the
moving and stationary conditions
2.5
2
1.5
1
0.5
0
Subject FT
Subject KM
Moving Condition
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.
Left eye
Indicator
Method
Right eye
Fixation point
Visual awareness
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 Awareness
Visual qualia
Conclusion