Abstract
Although motor deficits are common in autism, the neural correlates underlying the disruption of even basic motor execution are unknown. Motor deficits may be some of the earliest identifiable signs of abnormal development and increased understanding of their neural underpinnings may provide insight into autism-associated differences in parallel systems critical for control of more complex behaviour necessary for social and communicative development. Functional magnetic resonance imaging was used to examine neural activation and connectivity during sequential, appositional finger tapping in 13 children, ages 812 years, with high-functioning autism (HFA) and 13 typically developing (TD), age-and sex-matched peers. Both groups showed expected primary activations in cortical and subcortical regions associated with motor execution [contralateral primary sensorimotor cortex, contralateral thalamus, ipsilateral cerebellum, supplementary motor area (SMA)]; however, the TD group showed greater activation in the ipsilateral anterior cerebellum, while the HFA group showed greater activation in the SMA. Although activation differences were limited to a subset of regions, children with HFA demonstrated diffusely decreased connectivity across the motor execution network relative to control children. The between-group dissociation of cerebral and cerebellar motor activation represents the first neuroimaging data of motor dysfunction in children with autism, providing insight into potentially abnormal circuits impacting development. Decreased cerebellar activation in the HFA group may reflect difficulty shifting motor execution from cortical regions associated with effortful control to regions associated with habitual execution. Additionally, diffusely decreased connectivity may reflect poor coordination within the circuit necessary for automating patterned motor behaviour. The findings might explain impairments in motor development in autism, as well as abnormal and delayed acquisition of gestures important for socialization and communication.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2413-2425 |
| Number of pages | 13 |
| Journal | Brain |
| Volume | 132 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2009 |
Funding
National Alliance for Autism Research/Autism Speaks and from the National Institutes of Health (K02 NS 044850 to S.H.M.); (RO1 NS048527 to SHM); (K01 MH01824 to MCG); the Mental Retardation and Developmental Disabilities Research Center (HD-24061); the National Center for Resources (P41 RR15241); and the Johns Hopkins, University School of Medicine Institute for Clinical and Translational Research, an NIH/NCRR CTSA Program, UL1-RR025005. The National Center for Research Resources (NCRR) is a component of the National Institutes of Health (NIH). The contents of this paper are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH.
Keywords
- Connections
- Development
- Motor learning
- Movement
- Neuroimaging
- Pediatric
ASJC Scopus subject areas
- Clinical Neurology