Event Abstract Back to Event Dynamics of information processing explored via MEG Gordon Morison1*, Marie L. Smith2 and Philippe G. Schyns1 1 University of Glasgow, Center for Cognitive Neuroscience, United Kingdom 2 Cognition and Brain Sciences Unit, Medical Research Council (MRC), United Kingdom Recently utilizing the Bubbles paradigm (Gosselin and Schyns, 2001), in the context of the conscious perception of an ambiguous figure and oscillatory EEG measurements (Smith et al. 2006), we have identified the features that an observer uses to disambiguate the input, traced the time course of their processing in the brain directly from the oscillatory single sensor EEG, in different bands and revealed the perceptual moments when different features are integrated. Extending upon these developments, within MEG, we have used a frequency domain based beamformer (Gross et. al, 2001) allowing us to track the dynamics of stimulus spatial frequency processing within the brain in time, frequency and space. Five subjects participated within the experiment. On each trial, we exposed the visual system with a random subset of the Spatial Frequency (SF) information sampled from an ambiguous image. This ambiguous image induces two distinct phenomenal states: the perception of 'The Nuns' vs. 'Voltaire', from two distinct subsets of SF information. We decomposed the image into 5 independent SF bands from HSF to LSF For each SF band, a number of randomly located Gaussian apertures (the 'bubbles'), HSF to LSF, formed SF-specific 'bubble masks'. The sparse stimulus presented on each trial was generated by adding together the information randomly sampled from each band. Across a total of 6,000 trials per observer, we can estimate the SF information biases associated with each perception ('The Nuns' vs. 'Voltaire' vs. 'don't know'), for each observer. Data was recorded using a whole-head 248 channel MEG system (Magnes 3600, 4-D Neuroimaging). Our results demonstrate during the time scale from 150ms to 350ms that the stimulus spatial frequency information is maximally integrated within non overlapping oscillation bands for each perception. This suggests that the brain multiplexes the processing of the features of each perception across different cortical oscillatory bandwidths. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Sensory Processing and Functional Connectivity Citation: Morison G, Smith ML and Schyns PG (2010). Dynamics of information processing explored via MEG. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00190 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Mar 2010; Published Online: 29 Mar 2010. * Correspondence: Gordon Morison, University of Glasgow, Center for Cognitive Neuroscience, Glasgow, United Kingdom, gordon@psy.gla.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Gordon Morison Marie L Smith Philippe G Schyns Google Gordon Morison Marie L Smith Philippe G Schyns Google Scholar Gordon Morison Marie L Smith Philippe G Schyns PubMed Gordon Morison Marie L Smith Philippe G Schyns Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.
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