Relation of gamma oscillations in scalp recordings to muscular activity.

Full Abstract

We recorded scalp electrical activity before and after full neuro-muscular paralysis in 5 volunteers and determined differences due to elimination of muscular activity on several standard applications of EEG. Due to paralysis, there were reductions in 'noisiness' of the standard scalp recordings which were maximal over the peripheral scalp, not explained by abolition of movement artefact, and best accounted for by sustained EMG activity in resting individuals. There was a corresponding reduction in spectral power in the gamma range. In central leads, the extent of gamma frequency coherence during a non-time-locked mental task (1 s epochs) was reduced by paralysis, likely due to a reduction in gamma-frequency coherence in widely arising EMG signals. In a time-locked mental task (auditory oddball), evoked responses were qualitatively unaffected by paralysis but 3 of 4 induced gamma responses were obscured by EMG.

Author information

Author/s: Pope, Kenneth J (KJ); Fitzgibbon, Sean P (SP); Lewis, Trent W (TW); Whitham, Emma M (EM); Willoughby, John O (JO);

Affiliation: School of Computer Science, Engineering and Mathematics, Flinders University, Adelaide, Australia. Kenneth.Pope(-atsign-)flinders.edu.au

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Brain topography (Brain Topogr), published in United States. (Language: eng)

Reference: 2009-Jun; vol 22 (issue 1) : pp 13-7

Dates: Created 2009/07/17; Completed 2009/10/01;

PMID: 19229605, status: MEDLINE (last retrieved date: 10/1/2009)

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