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Unconscious inference and conscious representation: Why primary visual cortex (V1) is directly involved in visual awareness

Published online by Cambridge University Press:  14 May 2008

Zhicheng Lin
Affiliation:
Department of Psychology, University of Minnesota, Minneapolis, MN 55455. [email protected]://zhichenglin.googlepages.com/

Abstract

The extent to which visual processing can proceed in the visual hierarchy without awareness determines the magnitude of perceptual delay. Increasing data demonstrate that primary visual cortex (V1) is involved in consciousness, constraining the magnitude of visual delay. This makes it possible that visual delay is actually within the optimal lengths to allow sufficient computation; thus it might be unnecessary to compensate for visual delay.

The time delay problem – that perception lives slightly in the past as a result of neural conduction – has recently attracted a considerate amount of attention in the context of the flash-lag effect. The effect refers to a visual illusion wherein a brief flash of light and a continuously moving object that physically align in space and time are perceived to be displaced from one another – the flashed stimulus appears to lag behind the moving object (Krekelberg & Lappe 2001). In the target article, Nijhawan compellingly argues that delay compensation could be undertaken by a predictive process in the feedforward pathways in the vision system. Before jumping into the quest for the mechanism of delay compensation, however, I would like to argue that the magnitude of delay has been overestimated, and that it might even be unnecessary to compensate for such a delay.

Type
Open Peer Commentary
Copyright
Copyright ©Cambridge University Press 2008

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References

Blake, R., Tadin, D., Sobel, K. V., Raissian, T. A. & Chong, S. C. (2006) Strength of early visual adaptation depends on visual awareness. Proceedings of the National Academy of Sciences USA 103(12):4783–88.CrossRefGoogle ScholarPubMed
Crick, F. & Koch, C. (1995) Are we aware of neural activity in primary visual cortex? Nature 375(6527):121–23.CrossRefGoogle ScholarPubMed
He, S., Cavanagh, P. & Intriligator, J. (1996) Attentional resolution and the locus of visual awareness. Nature 383(6598):334–37.CrossRefGoogle ScholarPubMed
Jiang, Y., Zhou, K. & He, S. (2007) Human visual cortex responds to invisible chromatic flicker. Nature Neuroscience 10(5):657–62.CrossRefGoogle ScholarPubMed
Krekelberg, B. & Lappe, M. (2001) Neuronal latencies and the position of moving objects. Trends in Neurosciences 24:335–39.CrossRefGoogle ScholarPubMed
Lamme, V. A. & Roelfsema, P. R. (2000) The distinct modes of vision offered by feedforward and recurrent processing. Trends in Neuroscience 23(11):571–z79.CrossRefGoogle ScholarPubMed
Lin, Z. & He, S. (in press) Seeing the invisible: The scope and limits of unconscious processing in binocular rivalry. Progress in NeurobiologyGoogle Scholar
Treisman, A. (1996) The binding problem. Current Opinions in Neurobiology 6(2):171–78.CrossRefGoogle ScholarPubMed