BibTeX
@MISC{_regionalresolving,
author = {},
title = {Regional Resolving Power of Combined MEG/EEG},
year = {}
}
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Abstract
Different modeling frameworks (such as error analyses for dipole localization [Fuchs, 1998; Huizenga, 2001]; crosstalk and point spread analyses for linear estimators [Liu, 2002]; etc.) have demonstrated improved three-dimensional (3D) resolution for combined MEG/EEG (or EMEG) source estimation. Complementary to these, an empirical analysis of 2D surface data suggested that MEG and EEG information content could be superadditive [Pflieger, 2000]. Taking a hybrid approach in the present study, we made simulations within a regional activity estimation (REGAE, [Pflieger, 2001]) framework, which quantifies the ability of EMEG to discriminate brain activity originating within a 3D region of interest (ROI) from simultaneous non-ROI activity. Two metrics were employed: Kullback-Leibler divergence (KLD) and area under the receiver operator characteristic curve (AUROC). High-density sensor configurations (248 magnetometers, 256 electrodes) were combined with a gray matter source space model (7931 dipole triples, maximum entropy activities), assuming magnetic 3-shell sphere and electric BEM head models. Superadditive KLD was observed frequently across 89 representative brain ROIs and 3 ROI sizes (5, 10, and 15 mm radii), especially for regions already fairly visible to each modality. We also report an observed functional relationship between AUROC and KLD.
Keyphrases
combined meg eeg regional resolving power hybrid approach magnetic 3-shell dipole localization fuchs linear estimator observed functional relationship maximum entropy activity dipole triple regional activity estimation superadditive pflieger surface data brain activity empirical analysis mm radius electric bem head model point spread analysis gray matter source space model representative brain roi present study superadditive kld high-density sensor configuration roi size simultaneous non-roi activity eeg information content receiver operator characteristic curve source estimation kullback-leibler divergence
