title: Rapid online language mapping with electrocorticography.
abstract: OBJECTIVE
  Emerging research in evoked broadband electrocorticographic (ECoG) measurement from the cortical surface suggests that it might cleanly delineate the functional organization of cortex. The authors sought to demonstrate whether this could be done in a same-session, online manner to identify receptive and expressive language areas.
  
  
  METHODS
  The authors assessed the efficacy of simple integration of "χ-band" (76-200 Hz) change in the ECoG signal by implementing a simple band-pass filter to estimate broadband spectral change. Following a brief (less than 10-second) period to characterize baseline activity, χ-band activity was integrated while 7 epileptic patients with implanted ECoG electrodes performed a verb-generation task.
  
  
  RESULTS
  While the patients were performing verb-generation or noun-reading tasks, cortical activation was consistently identified in primary mouth motor area, superior temporal gyrus, and Broca and Wernicke association areas. Maps were robust after a mean time of 47 seconds (using an "activation overlap" measure). Correlation with electrocortical stimulation was not complete and was stronger for noun reading than verb generation.
  
  
  CONCLUSIONS
  Broadband ECoG changes can be captured online to identify eloquent cortex. This demonstrates the existence of a powerful new tool for functional mapping in the operative and chronic implant setting.
authors.affiliation: Department of Neurological Surgery, University of Washington, Seattle, Washington 98195, USA. kjmiller@uw.edu
authors.forename: Kai J
authors.initials: KJ
authors.lastname: Miller
authors.forename: Taylor J
authors.initials: TJ
authors.lastname: Abel
authors.forename: Adam O
authors.initials: AO
authors.lastname: Hebb
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ojemann
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D010153:Paired-Associate Learning / Q000502:physiology; D011932:Reading; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014057:Tomography, X-Ray Computed; D014705:Verbal Behavior / Q000502:physiology; D055815:Young Adult