title: Eye closure causes widespread low-frequency power increase and focal gamma attenuation in the human electrocorticogram.
abstract: OBJECTIVE
  We sought to characterize the effects of eye closure on EEG power using electrocorticography (ECoG). Specifically, we sought to elucidate the anatomical areas demonstrating an eye closure effect, and at which frequencies this effect occurs.
  
  
  METHODS
  ECoG was recorded from 32 patients undergoing invasive monitoring for seizure focus localization. Patients were instructed to close and open their eyes repeatedly. ECoG power was compared in the epochs following eye closure and opening, for various frequency bands and brain regions.
  
  
  RESULTS
  We found that at low frequencies, eye closure causes widespread power increases involving all lobes of the brain. This effect was significant not only in the α (8-12 Hz) band but in the δ (2-4 Hz), θ (4-8 Hz), and β (15-30 Hz) bands as well. At high frequencies, eye closure causes comparatively focal power decreases over occipital cortex and frontal Brodmann areas 8 and 9.
  
  
  CONCLUSIONS
  Eye closure (1) affects a broad range of frequencies outside the α band and (2) involves a distributed network of neural activity in anatomical areas outside visual cortex.
  
  
  CONCLUSIONS
  This study constitutes the first large-scale, systematic application of ECoG to study eye closure, which is shown to influence a broad range of frequencies and brain regions.
authors.affiliation: Department of Psychology, University of Pennsylvania, 19104, United States. Electronic address: aaron.geller@nyumc.org.
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Geller
authors.affiliation: Neuroscience Graduate Group, University of Pennsylvania, 19104, United States.
authors.forename: John F
authors.initials: JF
authors.lastname: Burke
authors.affiliation: Department of Neurology, Thomas Jefferson University, 19107, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sperling
authors.affiliation: Department of Neurological Surgery, Thomas Jefferson University, 19107, United States.
authors.forename: Ashwini D
authors.initials: AD
authors.lastname: Sharan
authors.affiliation: Department of Neurology, University of Pennsylvania School of Medicine, 19104, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Litt
authors.affiliation: Department of Neurosurgery, University of Pennsylvania School of Medicine, 19104, United States.
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Baltuch
authors.affiliation: Department of Neurosurgery, University of Pennsylvania School of Medicine, 19104, United States.
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Lucas
authors.affiliation: Department of Psychology, University of Pennsylvania, 19104, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kahana
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001611:Beta Rhythm; D002540:Cerebral Cortex / Q000503:physiopathology; D003700:Delta Rhythm; D004569:Electroencephalography; D005260:Female; D065818:Gamma Rhythm; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D009799:Ocular Physiological Phenomena; D012640:Seizures / Q000503:physiopathology*; D013826:Theta Rhythm; D055815:Young Adult
keywords: Alpha; ECoG; Event-related synchronization; Eye closure; Frontal eye fields; Gamma; High frequency activity; Intracranial EEG