title: Functional Organization of the Action Observation Network in Autism: A Graph Theory Approach.
abstract: BACKGROUND
  The ability to recognize, understand and interpret other's actions and emotions has been linked to the mirror system or action-observation-network (AON). Although variations in these abilities are prevalent in the neuro-typical population, persons diagnosed with autism spectrum disorders (ASD) have deficits in the social domain and exhibit alterations in this neural network.
  
  
  METHODS
  Here, we examined functional network properties of the AON using graph theory measures and region-to-region functional connectivity analyses of resting-state fMRI-data from adolescents and young adults with ASD and typical controls (TC).
  
  
  RESULTS
  Overall, our graph theory analyses provided convergent evidence that the network integrity of the AON is altered in ASD, and that reductions in network efficiency relate to reductions in overall network density (i.e., decreased overall connection strength). Compared to TC, individuals with ASD showed significant reductions in network efficiency and increased shortest path lengths and centrality. Importantly, when adjusting for overall differences in network density between ASD and TC groups, participants with ASD continued to display reductions in network integrity, suggesting that also network-level organizational properties of the AON are altered in ASD.
  
  
  CONCLUSIONS
  While differences in empirical connectivity contributed to reductions in network integrity, graph theoretical analyses provided indications that also changes in the high-level network organization reduced integrity of the AON.
authors: Department of Kinesiology, Movement Control & Neuroplasticity Research Group, KU Leuven, Leuven, Belgium; Department of Rehabilitation Sciences, Neuromotor Rehabilitation Research Group, KU Leuven, Leuven, Belgium.
authors: Kaat
authors: K
authors: Alaerts
authors: Department of Kinesiology, Movement Control & Neuroplasticity Research Group, KU Leuven, Leuven, Belgium.
authors: Franca
authors: F
authors: Geerlings
authors: Department of Kinesiology, Movement Control & Neuroplasticity Research Group, KU Leuven, Leuven, Belgium.
authors: Lynn
authors: L
authors: Herremans
authors: Department of Kinesiology, Movement Control & Neuroplasticity Research Group, KU Leuven, Leuven, Belgium.
authors: Stephan P
authors: SP
authors: Swinnen
authors: Department of Imaging & Pathology, Translational MRI, KU Leuven, Leuven, Belgium.
authors: Judith
authors: J
authors: Verhoeven
authors: Department of Imaging & Pathology, Translational MRI, KU Leuven, Leuven, Belgium.
authors: Stefan
authors: S
authors: Sunaert
authors: Department Health Sciences and Technology, Neural Control of Movement Lab, ETH Zurich, Zurich, Switzerland.
authors: Nicole
authors: N
authors: Wenderoth
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D003196:Computer Graphics; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000503:physiopathology*; D012919:Social Behavior; D055815:Young Adult