Perceptual moments of conscious visual experience inferred from oscillatory brain activity

Smith, M., Gosselin, F. and Schyns, P. (2006) Perceptual moments of conscious visual experience inferred from oscillatory brain activity. Proceedings of the National Academy of Sciences of the United States of America, 103(14), pp. 5626-5631. (doi:10.1073/pnas.0508972103)

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Abstract

Transient periods of synchronized oscillating neuronal discharges in the brain have been proposed to support the discrete perceptual moments underlying conscious visual experience. However, the information content of these perceptual moments remains a critical challenge to the understanding of consciousness. We uncovered this information content in four observers who consciously perceived each interpretation of the ambiguous Dali painting Slave Market with the Disappearing Bust of Voltaire. For each individual observer, we isolated the stimulus spatial frequency (SF) features underlying their overt judgments of the input as “the nuns” and “Voltaire”. Every 2 ms between stimulus onset and overt response, we derived the sensitivity of the observer's oscillatory brain activity (in the theta, alpha, and beta bandwidths) to these SF features. Then, in each bandwidth, we estimated the moments (between stimulus onset and perceptual judgment) when perception-specific SF features were maximally integrated, corresponding to perceptual moments. We show that the centroparietal beta oscillations support perceptual moments underlying the conscious perception of the nuns, whereas theta oscillations support the perception of Voltaire. For both perceptions, we reveal the specific information content of these perceptual moments.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Schyns, Professor Philippe and Smith, Dr Marie
Authors: Smith, M., Gosselin, F., and Schyns, P.
College/School:College of Science and Engineering > School of Psychology
College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:Proceedings of the National Academy of Sciences of the United States of America
Publisher:National Academy of Sciences
ISSN:0027-8424
ISSN (Online):1091-6490

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