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Thinking activates EMG in scalp electrical recordings
- Source :
- Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 119(5)
- Publication Year :
- 2007
-
Abstract
- Objective Fast electrical rhythms in the gamma range (30–100 Hz) in scalp (but not intracranial) recordings are predominantly due to electromyographic (EMG) activity. We hypothesized that increased EMG activity would be augmented by mental tasks in proportion to task difficulty and the requirement of these tasks for motor or visuo-motor output. Methods EEG was recorded in 98 subjects whilst performing cognitive tasks and analysed to generate power spectra. In four other subjects, neuromuscular blockade was achieved pharmacologically providing EMG-free spectra of EEG at rest and during mental tasks. Results In comparison to the paralysed condition, power of scalp electrical recordings in the gamma range varied in distribution, being maximal adjacent to cranial or cervical musculature. There were non-significant changes in mean gamma range activity due to mental tasks in paralysed subjects. In normal subjects, increases in scalp electrical activity were observed during tasks, without relationship to task difficulty, but with tasks involving limb- or eye-movement having higher power. Conclusions Electrical rhythms in the gamma frequency range recorded from the scalp are inducible by mental activity and are largely due to EMG un-related to cognitive effort. EMG varies with requirements for somatic or ocular movement more than task difficulty. Significance Severe restrictions exist on utilizing scalp recordings for high frequency EEG.
- Subjects :
- Adult
Male
Elementary cognitive task
medicine.medical_specialty
Electromyography
Electroencephalography
Audiology
behavioral disciplines and activities
Thinking
Rhythm
Physiology (medical)
medicine
Humans
Paralysis
Muscle, Skeletal
Aged
Scalp
medicine.diagnostic_test
Eye movement
Brain
Body movement
Middle Aged
Sensory Systems
body regions
Electrophysiology
medicine.anatomical_structure
Neurology
Atracurium
Neurology (clinical)
Neuromuscular Blocking Agents
Psychology
Artifacts
Neuroscience
psychological phenomena and processes
Subjects
Details
- ISSN :
- 13882457
- Volume :
- 119
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
- Accession number :
- edsair.doi.dedup.....69800cedfc053258d66f03959c055339