ADD / ADHD, Autism, Balance & Coordination, Dyscalculia

The Cerebellum. Does Size Matter?

The delightful Christiaan contacted me the other day with two links to investigate. The first was a study covered in New Scientist on neurofeedback, autism and mirror neurons. The second was to a video of a presentation made in 2003 on the cognitive neuroscience of ADHD. Unfortunately it would not play on my computer but there was a link to the associated slide show that was very interesting. The slides cover a lot of areas though focus on a study of response inhibition in ADHD sufferers.

What caught my eye was a reference to work showing that the cerebellum is smaller in people with ADHD. The study, Cerebellum in attention-deficit hyperactivity disorder: a morphometric MRI study, found that in boys with ADHD some areas of the cerebellim were significantly smaller than non-sufferers. This is of note because the cerebellum controls motor movement and has a role in memory and cognitive abilities. Treatments such as the Dore Programme (coverage on Myomancy) and Learning Breakthrough are design to train the cerebellum. Their approach is based on the idea that if dyslexia / ADHD is caused by a underdeveloped cerebellum then exercising the cerebellum will relieve the problems of dyslexia and ADHD.

With my curiosity piqued I decide to trawl through Google Scholar looking for research on how the size of the cerebellum affects our abilities.

Top of the pile was another study on ADHD and the cerebellum, Evaluation of cerebellar size in attention-deficit hyperactivity disorder, that also found it to be smaller in ADHD sufferers.

The second study was more interesting. The study, Cerebellar size and cognition: correlations with IQ, verbal memory and motor dexterity, found that participants’ verbal memory and fine motor skills were directly correlated to the size of the cerebellum. These are key areas of weakness in people with dyslexia. General intelligence was also correlated to cerebellum size but not enough to be statistically significant.

Looking at prematurely born babies, Cognitive and motor function and the size of the cerebellum in adolescents born very pre-term, researchers found that the cerebellum had “significantly reduced cerebellar volume” compared to full term babies. We have previously reported on Myomancy that Premature Babies Have High Chance of Learning Disabilites.

Size does seem to matter but its not 100% clear exactly how. In a study looking at autistic children, An MRI study of autism: the cerebellum revisited, scientists from the University of Iowa discovered that autistics had a larger cerebellum than normal.

Drifting off topic onto one final study, Relative Volume of the Cerebellum in Dolphins and Comparison with Anthropoid Primates, asks the question “How large are dolphin cerebellum compared to primates?”. A reasonable question given that dolphins and apes are believed to have relatively high intelligence. It turns out that dolphins have a significantly larger cerebellum than both apes and humans. What this tells us about the cerebellum and intelligence I’m not sure.