Reorganization of functionally connected brain subnetworks in high-functioning autism

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Åbo Akademi University
  • University of Turku
  • Turku PET Centre
  • Helsinki University Central Hospital
  • Neuromental

Abstract

Previous functional connectivity studies have found both hypo- and hyper-connectivity in brains of individuals having autism spectrum disorder (ASD). Here we studied abnormalities in functional brain subnetworks in high-functioning individuals with ASD during free viewing of a movie containing social cues and interactions. Twenty-six subjects (13 with ASD) watched a 68-min movie during functional magnetic resonance imaging. For each subject, we computed Pearson's correlation between haemodynamic time-courses of each pair of 6-mm isotropic voxels. From the whole-brain functional networks, we derived individual and group-level subnetworks using graph theory. Scaled inclusivity was then calculated between all subject pairs to estimate intersubject similarity of connectivity structure of each subnetwork. Additional 54 individuals (27 with ASD) from the ABIDE resting-state database were included to test the reproducibility of the results. Between-group differences were observed in the composition of default-mode and ventro-temporal-limbic (VTL) subnetworks. The VTL subnetwork included amygdala, striatum, thalamus, parahippocampal, fusiform, and inferior temporal gyri. Further, VTL subnetwork similarity between subject pairs correlated significantly with similarity of symptom gravity measured with autism quotient. This correlation was observed also within the controls, and in the reproducibility dataset with ADI-R and ADOS scores. Our results highlight how the reorganization of functional subnetworks in individuals with ASD clarifies the mixture of hypo- and hyper-connectivity findings. Importantly, only the functional organization of the VTL subnetwork emerges as a marker of inter-individual similarities that co-vary with behavioral measures across all participants. These findings suggest a pivotal role of ventro-temporal and limbic systems in autism. Hum Brain Mapp 37:1066-1079, 2016.

Details

Original languageEnglish
Pages (from-to)1066-1079
Number of pages14
JournalHuman Brain Mapping
Volume37
Issue number3
Publication statusPublished - 1 Mar 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • Autism spectrum disorder, FMRI, Functional connectivity, Graph theory, Intersubject similarity, Network modularity

ID: 1591229