title: Gamma activity modulated by picture and auditory naming tasks: intracranial recording in patients with focal epilepsy.
abstract: OBJECTIVE
  We measured the spatial, temporal and developmental patterns of gamma activity augmented by picture- and auditory-naming tasks and determined the clinical significance of naming-related gamma-augmentation.
  
  
  METHODS
  We studied 56 epileptic patients (age: 4-56 years) who underwent extraoperative electrocorticography. The picture-naming task consisted of naming of a visually-presented object; the auditory-naming task consisted of answering an auditorily-presented sentence question.
  
  
  RESULTS
  Naming-related gamma-augmentation at 50-120 Hz involved the modality-specific sensory cortices during stimulus presentation and inferior-Rolandic regions during responses. Gamma-augmentation in the bilateral occipital and inferior/medial-temporal regions was more intense in the picture-naming than auditory-naming task, whereas that in the bilateral superior-temporal, left middle-temporal, left inferior-parietal, and left frontal regions was more intense in the auditory-naming task. Patients above 10 years old, compared to those younger, showed more extensive gamma-augmentation in the left dorsolateral-premotor region. Resection of sites showing naming-related gamma-augmentation in the left hemisphere assumed to contain essential language function was associated with increased risk of post-operative language deficits requiring speech therapy (p < 0.05).
  
  
  CONCLUSIONS
  Measurement of gamma-augmentation elicited by either naming task was useful to predict postoperative language deficits.
  
  
  CONCLUSIONS
  A smaller degree of frontal engagement in the picture-naming task can be explained by no requirement of syntactic processing or less working memory load. More extensive gamma-augmentation in the left dorsolateral-premotor region in older individuals may suggest more proficient processing by the mature brain.
authors.affiliation: Department of Pediatrics, Wayne State University, Detroit Medical Center, Detroit, MI 48201, USA.
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Kojima
authors.forename: Erik C
authors.initials: EC
authors.lastname: Brown
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Matsuzaki
authors.forename: Robert
authors.initials: R
authors.lastname: Rothermel
authors.forename: Darren
authors.initials: D
authors.lastname: Fuerst
authors.forename: Aashit
authors.initials: A
authors.lastname: Shah
authors.forename: Sandeep
authors.initials: S
authors.lastname: Mittal
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sood
authors.forename: Eishi
authors.initials: E
authors.lastname: Asano
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000502:physiology / Q000503:physiopathology; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D004585:Electrooculography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D009626:Terminology as Topic; D014705:Verbal Behavior / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Epilepsy surgery; High-frequency oscillations (HFOs); Intracranial ECoG recording; Language; Outcome; Ripples; Speech