The study of autism as a distributed disorder
Article first published online: 26 FEB 2007
Copyright © 2007 Wiley-Liss, Inc.
Mental Retardation and Developmental Disabilities Research Reviews
Special Issue: Language and Communication
Volume 13, Issue 1, pages 85–95, 2007
How to Cite
Müller, R.-A. (2007), The study of autism as a distributed disorder. Ment. Retard. Dev. Disabil. Res. Rev., 13: 85–95. doi: 10.1002/mrdd.20141
- Issue published online: 26 FEB 2007
- Article first published online: 26 FEB 2007
- Manuscript Accepted: 26 DEC 2006
- Manuscript Received: 22 DEC 2006
- National Institutes of Health. Grant Numbers: R01-NS43999, R01-DC6155
- brain imaging;
- functional networks
Past autism research has often been dedicated to tracing the causes of the disorder to a localized neurological abnormality, a single functional network, or a single cognitive-behavioral domain. In this review, I argue that autism is a “distributed disorder” on various levels of study (genetic, neuroanatomical, neurofunctional, behavioral). “Localizing” models are therefore not promising. The large array of potential genetic risk factors suggests that multiple (or all) emerging functional brain networks are affected during early development. This is supported by widespread growth abnormalities throughout the brain. Interactions during development between affected functional networks and atypical experiential effects (associated with atypical behavior) in children with autism further complicate the neurological bases of the disorder, resulting in an “exponentially distributed” profile. Promising approaches to a better characterization of neural endophenotypes in autism are provided by techniques investigating white matter and connectivity, such as MR spectroscopy, diffusion-tensor imaging (DTI), and functional connectivity MRI. According to a recent hypothesis, the autistic brain is generally characterized by “underconnectivity.” However, not all findings are consistent with this view. The concepts and methodology of functional connectivity need to be refined and results need to be corroborated by anatomical studies (such as DTI tractography) before definitive conclusions can be drawn. © 2007 Wiley-Liss, Inc. MRDD Research Reviews 2007;13:85–95.