title: Gamma activation in young people with autism spectrum disorders and typically-developing controls when viewing emotions on faces.
abstract: BACKGROUND
  Behavioural studies have highlighted irregularities in recognition of facial affect in children and young people with autism spectrum disorders (ASDs). Recent findings from studies utilising electroencephalography (EEG) and magnetoencephalography (MEG) have identified abnormal activation and irregular maintenance of gamma (>30 Hz) range oscillations when ASD individuals attempt basic visual and auditory tasks.
  
  
  RESULTS
  The pilot study reported here is the first study to use spatial filtering techniques in MEG to explore face processing in children with ASD. We set out to examine theoretical suggestions that gamma activation underlying face processing may be different in a group of children and young people with ASD (n = 13) compared to typically developing (TD) age, gender and IQ matched controls. Beamforming and virtual electrode techniques were used to assess spatially localised induced and evoked activity. While lower-band (3-30 Hz) responses to faces were similar between groups, the ASD gamma response in occipital areas was observed to be largely absent when viewing emotions on faces. Virtual electrode analysis indicated the presence of intact evoked responses but abnormal induced activity in ASD participants.
  
  
  CONCLUSIONS
  These findings lend weight to previous suggestions that specific components of the early visual response to emotional faces is abnormal in ASD. Elucidation of the nature and specificity of these findings is worthy of further research.
authors.affiliation: Lime Trees Child, Family and Adolescent Unit, North Yorkshire and York Primary Care Trust, York, United Kingdom. barry.wright1@nhs.net
authors.forename: Barry
authors.initials: B
authors.lastname: Wright
authors.forename: Ben
authors.initials: B
authors.lastname: Alderson-Day
authors.forename: Garreth
authors.initials: G
authors.lastname: Prendergast
authors.forename: Sophie
authors.initials: S
authors.lastname: Bennett
authors.forename: Jo
authors.initials: J
authors.lastname: Jordan
authors.forename: Clare
authors.initials: C
authors.lastname: Whitton
authors.forename: Andre
authors.initials: A
authors.lastname: Gouws
authors.forename: Nick
authors.initials: N
authors.lastname: Jones
authors.forename: Ram
authors.initials: R
authors.lastname: Attur
authors.forename: Heather
authors.initials: H
authors.lastname: Tomlinson
authors.forename: Gary
authors.initials: G
authors.lastname: Green
mesh_terms: D000293:Adolescent; D058256:Brain Waves; D016022:Case-Control Studies; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000503:physiopathology* / Q000523:psychology; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009778:Occipital Lobe / Q000503:physiopathology; D011930:Reaction Time; D021641:Recognition, Psychology; D012044:Regression Analysis; D013702:Temporal Lobe / Q000503:physiopathology