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Dawei W. Dong; Sensory-motor integration during free-viewing natural time-varying images: A theory of dynamic processing in visual systems. Journal of Vision 2005;5(8):843. doi: 10.1167/5.8.843.
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We explore the hypothesis that early visual systems improve the efficiency of visual representation by dynamically changing the response properties to maintain the decorrelation of natural time-varying images. Natural time-varying images possess significant spatiotemporal correlations. Furthermore, under natural viewing conditions, such correlations are changed significantly by the saccadic eye movements and hence the visual signal has quite different characteristics during, across, and between saccadic eye movements.
Maintaining decorrelation of such visual signal requires that the response properties of the visual system also change accordingly. In addition, since the saccadic eye movements are generated and thus known to the brain, sensory changes induced by such self movements will be processed differently in comparison to sensory changes induced by intrinsic changes of the external world. Based on the measured statistical properties of visual input during free viewing of natural time-varying images, we derive the dynamic receptive-fields that achieve this decorrelation.
In particular, the derived receptive-fields change according to the timings of saccades. One of the predicted properties is the dynamic change of the response sensitivity to sinusoidal gratings of different spatial frequencies. This is compared with human psychophysical experiments and neurophysiological experiments in LGN of animals. Another predicted property is the dynamic change of the direction selectivity. This is compared with neurophysiological experiments in visual cortex of animals and functional imaging experiments in human.
The theory gives a quantitative account for visual response differences across and between saccades.
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