Gail, Alexander and Brinksmeyer, Hans Joerg and Eckhorn, Reinhard (2004) Perception-related modulations of local field potential power and coherence in primary visual cortex of awake monkey during binocular rivalry. Cerebral Cortex, 14 (3). pp. 300-313. ISSN 1047-3211 http://resolver.caltech.edu/CaltechAUTHORS:GAIcecor04
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Cortical synchronization at γ-frequencies (35–90 Hz) has been proposed to define the connectedness among the local parts of a perceived visual object. This hypothesis is still under debate. We tested it under conditions of binocular rivalry (BR), where a monkey perceived alternations among conflicting gratings presented singly to each eye at orthogonal orientations. We made multi-channel microelectrode recordings of multi-unit activity (MUA) and local field potentials (LFP) from striate cortex (V1) during BR while the monkey indicated his perception by pushing a lever. We analyzed spectral power and coherence of MUA and LFP over 4–90 Hz. As in previous work, coherence of γ-signals in most pairs of recording locations strongly depended on grating orientation when stimuli were presented congruently in both eyes. With incongruent (rivalrous) stimulation LFP power was often consistently modulated in consonance with the perceptual state. This was not visible in MUA. These perception-related modulations of LFP occurred at low and medium frequencies (<30 Hz), but not at γ-frequencies. Perception-related modulations of LFP coherence were also restricted to the low–medium range. In conclusion, our results do not support the expectation that γ-synchronization in V1 is related to the perceptual state during BR, but instead suggest a perception-related role of synchrony at low and medium frequencies.
|Additional Information:||© Oxford University Press 2004. Support by DFG to the research group ‘Dynamics of Cognitive Representation’ (DFG EC 53/9-3 to R.E.) is greatly acknowledged. We also thank Professor R. Bauer for help in experiments, W. Gerber, A. Rentzos and A. Platzner for their support in experimental techniques, and D. Leopold for instructive discussions on BR.|
|Subject Keywords:||object coding, synchronization, V1, visual awareness|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Lindsay Cleary|
|Deposited On:||08 Aug 2006|
|Last Modified:||26 Dec 2012 08:58|
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