Autism and unfavorable left-right asymmetries of the brain.
Autistic kids often have a right-wider-than-left back brain that may slow talking.
01Research in Context
What this study did
Doctors looked at brain scans of 12 autistic children. They measured the width of the back of each side of the brain.
They compared these widths to scans of kids without autism. The goal was to see if the sides matched in size.
What they found
Nine of the 12 autistic kids had a right side that was wider than the left. Only one non-autistic child showed this pattern.
The doctors thought this odd shape might link to the language delays many of the autistic children had.
How this fits with other research
Rysstad et al. (2016) found more left-hand use in autism. Their work widens the 1979 idea from the back of the brain to hand choice.
Matson et al. (2011) looked at tiny brain cells under the microscope. They saw messy layers in the same back area Blanchard et al. (1979) first flagged as lopsided.
Pan et al. (2021) pooled many studies and counted epilepsy, large heads, and other brain issues in autism. Their big-picture view now includes the 1979 asymmetry claim.
Why it matters
When you see late talking in an autistic client, remember the brain may be wired differently from side to side. This old scan study reminds us that uneven growth can sit under language struggles. Use that insight to push for early speech goals and to explain why some kids need extra time.
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02At a glance
03Original abstract
Utilizing computerized brain tomography, left-right morphologic asymmetries of the parietooccipital region were judged in 16 autistic patients, 44 mentally retarded patients, and 100 miscellaneous neurological patients. In 57% of the autistic patients the right parietooccipital region was wider than the left, while this pattern of cerebral asymmetry was found in only 23% of the mentally retarded patients and 25% of the neurological patients. It is suggested that unfavorable morphologic asymmetries of the brain near the posterior language zone may contribute to the difficulties autistic children experience in acquiring language.
Journal of autism and developmental disorders, 1979 · doi:10.1007/BF01531531