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Functional Mapping with Simultaneous MEG and EEG
Published on: June 15, 2010
Functional characterization of human second somatosensory cortex by magnetoencephalography
1Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT Espoo, Finland. yylin@vghtpe.gov.tw
Behavioural Brain Research
|October 3, 2002
Summary
Magnetoencephalography (MEG) reveals how the second somatosensory cortex (SII) processes tactile and pain signals and body awareness. SII activation patterns are influenced by muscle contractions and can be modulated by direct peripheral input.
Area of Science:
- Neuroscience
- Somatosensory System Research
- Brain Imaging
Background:
- Magnetoencephalography (MEG) offers noninvasive brain monitoring with high temporal and good spatial resolution.
- Previous studies highlight the functional characteristics of the second somatosensory cortex (SII) in humans.
- The SII cortex is known to process tactile input and is also responsive to nociceptive signals.
Purpose of the Study:
- To investigate the functional characteristics of the second somatosensory cortex (SII) using MEG.
- To explore the modulation of SII activation by various stimuli and conditions.
- To understand the role of SII in somatosensory processing and body scheme perception.
Main Methods:
- Whole-scalp neuromagnetic recordings using MEG.
- Unilateral median nerve stimulation in human subjects.
- Analysis of brain activity in response to tactile and nociceptive inputs.
- Assessment of SII modulation during isometric muscle contractions.
Main Results:
- MEG recordings showed activation of primary somatosensory cortex (SI) and bilateral SII cortex following median nerve stimulation.
- SII cortex responds to both tactile and nociceptive afferents.
- SII activation is differentially modulated by isometric muscle contractions.
- Evidence suggests SII cortex plays a role in body scheme perception and can receive direct ipsilateral peripheral input.
Conclusions:
- The SII cortex is a key region in processing somatosensory information, including tactile and nociceptive inputs.
- SII activation is dynamic and influenced by factors like muscle activity and peripheral input.
- Understanding SII function is crucial for comprehending body awareness and potential deficits following lesions.
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