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Sparsity enables estimation of both subcortical and cortical activity from MEG and EEG.

ABSTRACT: Subcortical structures play a critical role in brain function. However, options for assessing electrophysiological activity in these structures are limited. Electromagnetic fields generated by neuronal activity in subcortical structures can be recorded noninvasively, using magnetoencephalography (MEG) and electroencephalography (EEG). However, these subcortical signals are much weaker than those generated by cortical activity. In addition, we show here that it is difficult to resolve subcortical sources because distributed cortical activity can explain the MEG and EEG patterns generated by deep sources. We then demonstrate that if the cortical activity is spatially sparse, both cortical and subcortical sources can be resolved with M/EEG. Building on this insight, we develop a hierarchical sparse inverse solution for M/EEG. We assess the performance of this algorithm on realistic simulations and auditory evoked response data, and show that thalamic and brainstem sources can be correctly estimated in the presence of cortical activity. Our work provides alternative perspectives and tools for characterizing electrophysiological activity in subcortical structures in the human brain.

SUBMITTER: Krishnaswamy P

PROVIDER: S-EPMC5715738 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Sparsity enables estimation of both subcortical and cortical activity from MEG and EEG.

Krishnaswamy Pavitra P Obregon-Henao Gabriel G Ahveninen Jyrki J Khan Sheraz S Babadi Behtash B Iglesias Juan Eugenio JE Hämäläinen Matti S MS Purdon Patrick L PL

Proceedings of the National Academy of Sciences of the United States of America 20171114 48

Subcortical structures play a critical role in brain function. However, options for assessing electrophysiological activity in these structures are limited. Electromagnetic fields generated by neuronal activity in subcortical structures can be recorded noninvasively, using magnetoencephalography (MEG) and electroencephalography (EEG). However, these subcortical signals are much weaker than those generated by cortical activity. In addition, we show here that it is difficult to resolve subcortical ...[more]

PMID: 29138310

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Dataset Information

Sparsity enables estimation of both subcortical and cortical activity from MEG and EEG.

Publications

Sparsity enables estimation of both subcortical and cortical activity from MEG and EEG.

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