title: Atypical EEG complexity in autism spectrum conditions: a multiscale entropy analysis.
abstract: OBJECTIVE
  Intrinsic complexity subserves adaptability in biological systems. One recently developed measure of intrinsic complexity of biological systems is multiscale entropy (MSE). Autism spectrum conditions (ASC) have been described in terms of reduced adaptability at a behavioural level and by patterns of atypical connectivity at a neural level. Based on these observations we aimed to test the hypothesis that adults with ASC would show atypical intrinsic complexity of brain activity as indexed by MSE analysis of electroencephalographic (EEG) activity.
  
  
  METHODS
  We used MSE to assess the complexity of EEG data recorded from 15 participants with ASC and 15 typical controls, during a face and chair matching task.
  
  
  RESULTS
  Results demonstrate a reduction of EEG signal complexity in the ASC group, compared to typical controls, over temporo-parietal and occipital regions. No significant differences in EEG power spectra were observed between groups, indicating that changes in complexity values are not a reflection of changes in EEG power spectra.
  
  
  CONCLUSIONS
  The results are consistent with a model of atypical neural integrative capacity in people with ASC.
  
  
  CONCLUSIONS
  Results suggest that EEG complexity, as indexed by MSE measures, may also be a marker for disturbances in task-specific processing of information in people with autism.
authors.affiliation: Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Campo Grande 1749-016 Lisbon, Portugal. ac655@medschl.cam.ac.uk
authors.forename: Ana
authors.initials: A
authors.lastname: Catarino
authors.forename: Owen
authors.initials: O
authors.lastname: Churches
authors.forename: Simon
authors.initials: S
authors.lastname: Baron-Cohen
authors.forename: Alexandre
authors.initials: A
authors.lastname: Andrade
authors.forename: Howard
authors.initials: H
authors.lastname: Ring
mesh_terms: D000328:Adult; D001321:Autistic Disorder / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods*; D019277:Entropy; D006801:Humans; D008297:Male; D008959:Models, Neurological