Over the past decade, scores of researchers have used magnetic resonance imaging (MRI) to reveal structural abnormalities in the brains of people with autism. One of the most consistent findings is that thecortex is larger than normal during childhood and shrinks earlier than normal during adolescence.
A new study calls these findings into question. The study, published 10 December in Neuroimage, shows that head movement during structural MRI causes certain regions of the cortex to appear smaller and thinner than they actually are.
It’s too early to say whether head movements skewed the results of studies that reported structural abnormalities in the brains of people with autism. But the new findings underscore the importance of safeguarding against head motion during brain imaging. This is especially important for studies involving people with autism, who are known to move their heads in MRI scanners more than controls do.