There are virtually no differences in brain anatomy between people with autism and those without.
Published in Cerebral Cortex by Israeli researchers Shlomi Haar and colleagues, the new research reports that there are virtually no differences in brain anatomy between people with autism and those without.
The research included structural MRI scans from 539 people diagnosed with high-functioning autism spectrum disorder (ASD) and 573 controls. This makes the paper order of magnitude bigger than a typical structural MRI anatomy study in this field. The age range was 6 to 35.
The scans came from the public Autism Brain Imaging Data Exchange (ABIDE) database, a data-sharing initiative that pools scan from 18 different neuroimaging centers. Researchers examined the neuroanatomy of the cases and controls using the popular FreeSurfer software package.
What did they find? Well… not much. First off, the ASD group had no differences in overall brain size (intracranial volume). Nor were there any group differences in the volumes of most brain areas; the only significant finding here was an increased ventricle volume in the ASD group, but even this had a small effect size (d = 0.34). Enlarged ventricles are not specific to ASD by any means – the same thing has been reported in schizophrenia, dementia, and many other brain disorders.