| Contextual modulation of synchronization to random dots in the cat visual cortex. | |
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MedLine Citation:
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PMID: 15118794 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Synchronization of neuronal activity has been proposed as a binding mechanism for integration of image properties into one coherent percept. In the present study, we investigated the contextual modulation of synchronization to random dot patterns. Coherent motion of random dots evoked well synchronized responses in area 17 of anaesthetized cats when the stimulus was presented in the compound receptive field of recorded sites. Gradually changing the directional coherence of random dots in the surround while maintaining fully coherent motion of the stimulus in the receptive field significantly suppressed synchronization of neuronal activity for some stimulus conditions. However, usually one or two peaks of increased synchronization were found in the surround coherence tuning curves with low (8-12%) and/or moderate (25-50%) coherence in the surround. At the population level, synchronization was significantly depressed with incoherent motion in the receptive field and when both the surround and the receptive field were jointly stimulated with 0% coherence. The intriguing finding was the discovery of two distinct groups of cells with opposite synchronization changes dependent on the presence or absence of significant synchronization in their spontaneous activity. The latter group of neurons showed peaks of increased synchronization with lower surround coherence, thus probably being more sensitive to the direction of the surround motion. Overall, our findings support the notion that binding of stimulus properties can be achieved by synchronized activity of cortical cells. However, our findings go further than the original hypothesis of feature binding by synchrony to show that synchronization of cortical activity may be directly related to the decision making processes, which in turn are related to the threshold of perception of coherent motion. |
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Authors:
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S Shumikhina; J Guay; F Duret; S Molotchnikoff |
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Publication Detail:
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Type: Journal Article Date: 2004-04-30 |
Journal Detail:
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Title: Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale Volume: 158 ISSN: 0014-4819 ISO Abbreviation: Exp Brain Res Publication Date: 2004 Sep |
Date Detail:
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Created Date: 2004-08-13 Completed Date: 2004-11-22 Revised Date: 2009-11-11 |
Medline Journal Info:
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Nlm Unique ID: 0043312 Medline TA: Exp Brain Res Country: Germany |
Other Details:
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Languages: eng Pagination: 223-32 Citation Subset: IM |
Affiliation:
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Département de Sciences Biologiques, Université de Montréal, CP 6128, succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cats Cortical Synchronization* Electrophysiology Motion Perception / physiology* Neurons / physiology Photic Stimulation / methods* Random Allocation Visual Cortex / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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