It was with interest that I read about a new study showing that autism affects motor skills. Claudia Hilton and John Constantino of the University of Washington studied many children with autism on standardized tests of motor performance. They found that motor skills were saliently lacking in the vast majority of children they studied.
This relates to my own life as I have fairly bad motor impairments myself. I did not learn how to tie my shoes until age 8, and had great difficulty in performing this. Though I can print somewhat legibly with great effort, I still have a handwriting impairment and my scrawl looks very much like "brain-damaged" writing. I still remember in the early 1960s when I saw a variety of handwriting tutors and had to have my recess taken away for a brief time to find time to give me extra help in this area. I also had tutoring in perceptual motor skills designed to help these problems but to no avail. I have difficulty wrapping presents and other fine skilled movements. However, my ability to type is more than intact.
I wondered if this was part of my autism as I had read about Stephen Wiltshire, Temple Grandin and others with extraordinary fine motor skills. To this day, I have never met a person, autistic or otherwise, who has a "fine motor coordination problem" as I have. I had read that autistic persons generally score higher on the performance part of the Wechsler IQ test than on the verbal portion. With myself, the opposite is true, where there is about a 40 point discrepancy between my relatively high verbal IQ and low performance IQ. Some studies, such as the ones done by the Mottron group and Uta Frith as well as others, show that at least some autistics have superior ability in the block design test on the Wechsler performance. I score in the retarded range on this. So, I have wondered if there was a subtype of autism involving poor motor skills. It would appear, from this study, that I'm not the only one.
The authors of this study speculate that the brain processes that give rise to motor coordination and social skills are controlled by a common area. It's possible that the frontal lobes are a candidate as they mediate the mirror neuron areas which could be involved in social judgement. In a previous post I wrote about parallels in autism and frontotemporal dementia which included poor social skills. So, I have to wonder if this could be key to the etiology of my problems.
Some of the motor and perceptual impairments I have also exist in adult patients with lesions of the right hemisphere of the parietal lobes called constructional apraxia. However, I might not have this as Eric Courchesne pointed out to me that adult lesions and developmental lesions might have different etiologies. When their research group did an MRI scan on me, they found I had hypoplasia of lobules VI and VII of the cerebellar vermis as compared to a normal control. This could explain my good typing motor coordination. Perhaps if the cerebellar damage occurs early enough it won't affect some of the autistics motor performance. However, in light of this recent study, I wonder if the cerebellum could be involved. Though, I'm not sure if it is involved in social judgement.
What Courchesne told me may have been slightly contradicted in a study done in the 1970s by Ralph Maurer and Antonio Demasio showing parallels between autism and problems in adult neurology patients with frontal lobe and basal ganglia impairments.
The basal ganglia are other brain areas that are involved in motor performance.
The reticular formation is another. In 1964, Bernard Rimland speculated that this area may be involved in autism. I don't think there is any empirical evidence to back that up.
It was somewhat of a relief to read about this study, as it means I may not be as atypical an autistic as I thought. Knowing about motor impairments may someday give me a clue to the etiology of my problems. I await further research.