Comparative power spectral analysis of simultaneous elecroencephalographic and magnetoencephalographic recordings in humans suggests non-resistive extracellular mediaReportar como inadecuado




Comparative power spectral analysis of simultaneous elecroencephalographic and magnetoencephalographic recordings in humans suggests non-resistive extracellular media - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Journal of Computational Neuroscience

, Volume 29, Issue 3, pp 405–421

First Online: 10 August 2010Received: 01 September 2009Revised: 24 May 2010Accepted: 27 May 2010

Abstract

The resistive or non-resistive nature of the extracellular space in the brain is still debated, and is an important issue for correctly modeling extracellular potentials. Here, we first show theoretically that if the medium is resistive, the frequency scaling should be the same for electroencephalogram EEG and magnetoencephalogram MEG signals at low frequencies <10 Hz. To test this prediction, we analyzed the spectrum of simultaneous EEG and MEG measurements in four human subjects. The frequency scaling of EEG displays coherent variations across the brain, in general between 1-f and 1-f, and tends to be smaller in parietal-temporal regions. In a given region, although the variability of the frequency scaling exponent was higher for MEG compared to EEG, both signals consistently scale with a different exponent. In some cases, the scaling was similar, but only when the signal-to-noise ratio of the MEG was low. Several methods of noise correction for environmental and instrumental noise were tested, and they all increased the difference between EEG and MEG scaling. In conclusion, there is a significant difference in frequency scaling between EEG and MEG, which can be explained if the extracellular medium including other layers such as dura matter and skull is globally non-resistive.

KeywordsEEG MEG Local field potentials Extracellular resistivity Maxwell equations  Power-law Action Editor: Gaute T. Einevoll

Electronic supplementary material The online version of this article doi:10.1007-s10827-010-0263-2 contains supplementary material, which is available to authorized users.

N. Dehghani and C. Bédard are co-first authors.

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Autor: Nima Dehghani - Claude Bédard - Sydney S. Cash - Eric Halgren - Alain Destexhe

Fuente: https://link.springer.com/







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