International Meeting for Autism Research: Functional Connectivity of the Ventromedial Prefrontal Cortex In Children with Autism Spectrum Disorders

Functional Connectivity of the Ventromedial Prefrontal Cortex In Children with Autism Spectrum Disorders

Friday, May 13, 2011
Elizabeth Ballroom E-F and Lirenta Foyer Level 2 (Manchester Grand Hyatt)
9:00 AM
B. Deen1 and K. A. Pelphrey2, (1)Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, (2)Child Study Center, Yale University, New Haven, CT
Background:  Several lines of research have implicated abnormal neural connectivity as a possible etiological mechanism in Autism Spectrum Disorders (ASD).  Prior studies have found various alterations in functional connectivity, as assessed by resting-state fMRI, in individuals with ASDs.  For instance, several studies have noted abnormalities in functional connectivity of the default mode network, potentially involved self-referential cognition and theory of mind.  However, few studies have investigated functional connectivity in children with autism, to begin to address the developmental relevance of these alterations.

Objectives:  To assess large-scale cortical functional connectivity in children with and without autism, using resting-state fMRI.

Methods:  Resting-state fMRI data was collected in 25 typically developing (TD) children (age 8-17), 25 children with ASDs, and 50 typical adults.  Maps of functional connectivity were computed in each group, using a range of seeds defined functionally using a portion of the adult dataset.  Seeds included regions of the default mode, fronto-parietal attention, cingulo-insular control, and other networks.  These maps were compared between TD and ASD groups.

Results:  Overal, long-range cortical functional connections were largely similar in the TD and ASD groups, with few differences found.  However, we do find a striking difference in the functional connectivity of the ventromedial prefrontal cortex (vmPFC), particularly with other regions of the ventral default mode network subnetwork, such as parahippocampal and retrosplenial cortices.

Conclusions: In contrast with prior reports of global underconnectivity in individuals with ASD, cortical functional connectivity appears to be largely intact in children with ASD.  However, there is a marked reduction of connectivity of vmPFC, particularly with regions of the default mode network.  This may relate to prior findings of vmPFC-lesion-like behavioral abnormalities in ASD, and fMRI results indicating altered response properties of vmPFC.

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