title: Atypical network connectivity for imitation in autism spectrum disorder.
abstract: Imitation has been considered as one of the precursors for sociocommunicative development. Impairments of imitation in autism spectrum disorder (ASD) could be indicative of dysfunctional underlying neural processes. Neuroimaging studies have found reduced activation in areas associated with imitation, but a functional connectivity MRI network perspective of these regions in autism is unavailable. Functional and effective connectivity was examined in 14 male participants with ASD and 14 matched typically developing (TD) participants. We analyzed intrinsic, low-frequency blood oxygen level dependent (BOLD) fluctuations of three regions in literature found to be associated with imitation (inferior frontal gyrus [IFG], inferior parietal lobule [IPL], superior temporal sulcus [STS]). Direct group comparisons did not show significantly reduced functional connectivity within the imitation network in ASD. Conversely, we observed greater connectivity with frontal regions, particularly superior frontal and anterior cingulate gyri, in the ASD compared to TD group. Structural equation modeling of effective connectivity revealed a significantly reduced effect of IPL on IFG together with an increased influence of a region in dorsal prefrontal cortex (dPFC) on IFG in the ASD group. Our results suggest atypical connectivity of the imitation network with an enhanced role of dPFC, which may relate to behavioral impairments.
authors.affiliation: Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, CA 92120, United States.
authors.forename: Patricia
authors.initials: P
authors.lastname: Shih
authors.forename: Mark
authors.initials: M
authors.lastname: Shen
authors.forename: Birgit
authors.initials: B
authors.lastname: Ottl
authors.forename: Brandon
authors.initials: B
authors.lastname: Keehn
authors.forename: Michael S
authors.initials: MS
authors.lastname: Gaffrey
authors.forename: Ralph-Axel
authors.initials: RA
authors.lastname: Müller
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007100:Imitative Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology; D010100:Oxygen / Q000097:blood; D055815:Young Adult
chemical_list: D010100:Oxygen