Functional significance of the mu rhythm of human cortex: an electrophysiologic study with subdural electrodes

Santiago Arroyo, Ronald P. Lesser, Barry Gordon, Sumio Uematsu, Darryl Jackson, Robert Webber

Research output: Contribution to journalArticlepeer-review

179 Scopus citations


The existence of the mu rhythm and its general anatomical and physiological relationships are well known. There are few data, however, regarding the details of its anatomical and physiological specificity. We implanted fronto-temporal subdural electrode grids in 9 patients with intractable epilepsy to facilitate their surgical management. A 7-11 Hz cortical mu rhythm was observed in 5-16 electrodes located over the sensorimotor cortex as mapped by electrical stimulation. The mu rhythm was blocked by contralateral face and arm movements, passive movements of contralateral arm, and by ipsilateral arm movements. There was correspondence between the body area movement of which blocked the mu at a given site and the body region that was affected by stimulation at the same site. Power spectral analysis showed an overall decrease in power in all frequency bands. This was less prominent in the 14-100 Hz band resulting in a relative increase in high frequency power in association with movement. We conclude that both the presence and blocking of mu rhythm are specific to the somatic representation of the cortex from which it is recorded. Its functional significance may be similar to other sensory rhythms like the occipital alpha rhythm.

Original languageEnglish (US)
Pages (from-to)76-87
Number of pages12
JournalElectroencephalography and Clinical Neurophysiology
Issue number3
StatePublished - Sep 1993


  • Cortical mapping
  • EEG
  • Functional localization
  • High frequency activity
  • Mu rhythm
  • Subdural electrodes

ASJC Scopus subject areas

  • Neuroscience(all)
  • Clinical Neurology


Dive into the research topics of 'Functional significance of the mu rhythm of human cortex: an electrophysiologic study with subdural electrodes'. Together they form a unique fingerprint.

Cite this