IS NEUROPLASTICITY BEING OVEREXAGGERATED?
In this BBC video, psychologists discuss the potential for neuroplasticity, the phenomena whereby the brain changes in accordance with environmental demands. The question is whether discussion about neuroplasticity is starting to overexaggerate the malleable capacity of the human brain. The brain is more flexible that we think, goes the claim, it can adapt to new experiences, so long as we have the motivation to give something else a go.
Of course there is nothing wrong with encouraging people to learn new languages or baking skills. It also seems quite likely that, in taking up a new hobby, the brain adapts as new connections are needed to cope with the new task. In one famous study, Eleanor Maguire demonstrated that the posterior hippocampus of London taxi drivers showed greater volume than controls, whilst the controls had a larger anterior hippocampus. Her study was conducted before the widespread use of satnavs at a time when London taxi drivers had to study The Knowledge, namely the names and locations of every street in London. Since the hippocampus is a brain structure known for processing long term memory, it seems likely that the demands of learning all the street names in London led to redistribution of hippocampi grey matter.
Some of Maguire's participants had been taxi drivers for near on thirty years, and a correlation indicated that the longer their service, the greater the redistribution. In other words this was not a change that occurs over just a few months of years. It is also conceivable that the brain's malleability is not caused by environmental demands alone. Those who dedicate their working lives to learning The Knowledge might possess a talent for navigation meaning that their brains adapt to the motivation to learn street names, not just the practice of it.
Whilst there is evidence that the brain changes due to environmental demand, it does mean that the brain is flexible to the point that a given individual's brain is determined by new challenges. The way that this video presents the idea of 'rewiring the brain' rather suggests that the brain has an infinite capacity to reform just as soon as someone takes up a new hobby. The fact that it changes does not mean that the brain is subject to external stimuli.