Gray Matter Matters / Distinctions Between Autism and Asperger’s

Two articles that point to gray matter differences in people whose jobs require mental mapping and a paper concerning gray matter distribution in Autism and Asperger’s brain types

Boston Globe Online

Do our brains pay a price for GPS?

How a useful technology interferes with our ‘mental mapping’ — and what to do about it.  By Leon Neyfakh Globe Staff  August 18, 2013

Clip: “(Veronique) Bohbot, the McGill neuroscientist, started experimenting with navigation because of an interest in the way people’s brains change as a result of learning. Bohbot developed a method for using fMRI technology to distinguish between people who tended to find their way by going through a memorized list of step-by-step directions — what she calls “stimulus response strategy” — and those who were inclined to orient themselves by conjuring a mental map of the world around them. People who just follow directions, Bohbot found, tended to have less gray matter in their hippocampus, the part of the brain responsible for encoding spatial memories.”

“People whose everyday work is deeply dependent on mental mapping can show brain development that is particularly distinctive. A famous study published in 2000 by British neuroscientist Eleanor Maguire showed that taxi drivers in London with years of experience navigating the city’s complex geography had more gray matter in the posterior hippocampus compared to people who were not taxi drivers. The study underscores that how our brain works is subject to use; the brain is plastic, and the more mental mapping we do, the stronger our cognitive navigation skills and the bigger the part of the brain that encodes them.”

More at Boston Globe…


 The comparison of gray matter volume as a plastic result of how one ‘uses’ the brain, led me to a study on PubMed:

Detailed article: 

Can Asperger syndrome be distinguished from autism? An anatomic likelihood meta-analysis of MRI studies

Kevin K. Yu, BSc,* Charlton Cheung, PhD,* Siew E. Chua, BM BCh, and Gráinne M. McAlonan, MBBS, PhD The autism research program in the Department of Psychiatry University of Hong Kong


Fig. 1 Cerebral grey matter differences in people with autism (top panel) and Asperger syndrome (bottom panel) compared with controls. Blue clusters represent less grey matter, whereas red clusters represent greater grey matter.


An ALE meta-analysis of grey matter differences in studies of Asperger syndrome or autism supports the argument against the disorder being considered solely a milder form of autism in neuro-anatomic terms. Whereas grey matter differences in people with Asperger syndrome are indeed more sparse than those reported in studies of people with autism, the distribution and direction of differences in each category is distinctive. Asperger syndrome involves clusters of lower grey matter volume in the right hemisphere and clusters of greater grey matter volume in the left hemisphere. Autism leads to more extensive bilateral excess of grey matter. Both conditions share clusters of grey matter excess in the left ventral temporal lobe components of the extrastriate visual system. This summary of a rich VBM MRI data set has important implications for how we categorize people on the autism spectrum and cautions that mixing individuals with autism and Asperger syndrome may at times obscure important characteristics manifested in one or the other condition alone.











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