Cortical and subcortical correlates of electroencephalographic alpha rhythm modulation

Feige, B; Scheffler, K; Esposito, F; Di Salle, F; Hennig, J; Seifritz, E (2005). Cortical and subcortical correlates of electroencephalographic alpha rhythm modulation. Journal of neurophysiology, 93(5), pp. 2864-72. Bethesda, Md.: American Physiological Society 10.1152/jn.00721.2004

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Neural correlates of electroencephalographic (EEG) alpha rhythm are poorly understood. Here, we related EEG alpha rhythm in awake humans to blood-oxygen-level-dependent (BOLD) signal change determined by functional magnetic resonance imaging (fMRI). Topographical EEG was recorded simultaneously with fMRI during an open versus closed eyes and an auditory stimulation versus silence condition. EEG was separated into spatial components of maximal temporal independence using independent component analysis. Alpha component amplitudes and stimulus conditions served as general linear model regressors of the fMRI signal time course. In both paradigms, EEG alpha component amplitudes were associated with BOLD signal decreases in occipital areas, but not in thalamus, when a standard BOLD response curve (maximum effect at approximately 6 s) was assumed. The part of the alpha regressor independent of the protocol condition, however, revealed significant positive thalamic and mesencephalic correlations with a mean time delay of approximately 2.5 s between EEG and BOLD signals. The inverse relationship between EEG alpha amplitude and BOLD signals in primary and secondary visual areas suggests that widespread thalamocortical synchronization is associated with decreased brain metabolism. While the temporal relationship of this association is consistent with metabolic changes occurring simultaneously with changes in the alpha rhythm, sites in the medial thalamus and in the anterior midbrain were found to correlate with short time lag. Assuming a canonical hemodynamic response function, this finding is indicative of activity preceding the actual EEG change by some seconds.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > University Psychiatric Services > University Hospital of Psychiatry and Psychotherapy > Management

UniBE Contributor:

Esposito, Fabio

ISSN:

0022-3077

ISBN:

15601739

Publisher:

American Physiological Society

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:55

Last Modified:

04 May 2014 23:16

Publisher DOI:

10.1152/jn.00721.2004

PubMed ID:

15601739

Web of Science ID:

000228575200046

URI:

https://boris.unibe.ch/id/eprint/23588 (FactScience: 42734)

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