Plasticity and Functional Recovery Studies

Boyke et al found evidence in 60-year-olds taught new skill of juggling. Increase in grey matter in visual cortex, but changes were reversed when practice stopped.

Maguire found increased grey matter in the brains of taxi drivers compared with controls in two brain regions, the right and left hippocampi. The increased volume was found in the posterior (rear) hippocampus.

Villablanca and Hovda found that a baby with damage to one hemisphere who has had that hemisphere removed early in life shows no ill effects as an adult in terms of behaviour and cognitive impairments.

Blakemore and Mitchell demonstrated plasticity based on early experience in young kittens. Those reared in an environment of vertical black stripes could not recognise horizontal black stripes, and those reared in an environment of horizontal black stripes could not recognise vertical black stripes.

Hubel and Wiesel found that, when one eye of a cat was sown shut, the area of the brain responsible for processing information from it continued to operate, providing evidence for neuroplasticity.

Bezzola et al found that when given 40 hours of golf training, participants aged 40-60 showed evidence of changes to the neural representation of movement in the motor cortex. This supports neural plasticity, and that it can happen at potentially any age.

Elbert et al concluded that capacity for neural reorganisation is much greater in children than in adults. Adults require greatly extended practice to change behaviour compared to children with brain trauma.

Schneider et al found that the more time brain injury patients had spent in education (an indication of their cognitive reserve), the greater their chances of a disability-free recovery.

EB was operated on aged 2.5 years to remove a large benign tumour from his left hemisphere. Virtually all of the left hemisphere was removed. At the time his linguistic abilities disappeared. He was right-handed, and right-handed people have language localisation in their left hemisphere. After a rehabilitation programme his language abilities started to improve. By age 8 there were no problems in his language reported.

Follow-up at age 17 compared his language abilities with normal controls. Found that the right hemisphere had compensated for the left and he was functioning well linguistically, with minor grammatical problems. Scans of EB's brain showed his brain activity was practically identical to controls, showing functional recovery by a non-specialist hemisphere to at least a basic degree.