Identifying spatially overlapping local cortical networks with MEG


Recent modelling studies (Hadjipapas et al. [2009]: Neuroimage 44:1290-1303) have shown that it may be possible to distinguish between different neuronal populations on the basis of their macroscopically measured (EEG/MEG) mean field. We set out to test whether the different orientation columns contributing to a signal at a specific cortical location could be identified based on the measured MEG signal. We used 1.5deg square, static, obliquely oriented grating stimuli to generate sustained gamma oscillations in a focal region of primary visual cortex. We then used multivariate classifier methods to predict the orientation (left or right oblique) of the stimuli based purely on the time-series data from this one location. Both the single trial evoked response (0-300 ms) and induced post-transient power spectra (300-2,300 ms, 20-70 Hz band) due to the different stimuli were classifiable significantly above chance in 11/12 and 10/12 datasets respectively. Interestingly, stimulus-specific information is preserved in the sustained part of the gamma oscillation, long after perception has occurred and all neuronal transients have decayed. Importantly, the classification of this induced oscillation was still possible even when the power spectra were rank-transformed showing that the different underlying networks give rise to different characteristic temporal signatures.

Publication DOI:
Divisions: College of Health & Life Sciences > School of Psychology
Additional Information: © 2010 Wiley-Liss, Inc., A Wiley Company Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.
Uncontrolled Keywords: beamformer,classifier,gamma,grating,mean field,MEG,orientation,Clinical Neurology,Anatomy,Neurology,Radiology Nuclear Medicine and imaging,Radiological and Ultrasound Technology
Publication ISSN: 1097-0193
Last Modified: 05 Jan 2024 08:05
Date Deposited: 27 Jul 2016 13:35
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://onlineli ... .20912/abstract (Publisher URL)
PURE Output Type: Article
Published Date: 2010-07
Published Online Date: 2009-12-08
Accepted Date: 2009-08-30
Submitted Date: 2009-06-17
Authors: Duncan, Keith Kawabata
Hadjipapas, Avgis
Li, Sheng
Kourtzi, Zoe
Bagshaw, Andy
Barnes, Gareth



Version: Published Version

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