Road 'sense'

A new study published in the journal Proceedings of the National Academy of Sciences indicates that taxi drivers in London are working their brains so hard that it has become enlarged in the zone associated with navigation -- the rear hippocampus. It seemed that the drivers' brains have adapted to help them store a detailed mental map of the city, shrinking in one area to allow growth in another. Evidence that the brain is physically able to change according to the way it is used could have important implications for people suffering from brain diseases such as Alzheimer's. In the study, researchers at University College, London University, compared the brains of 16 male taxi drivers with those of 50 other men of a similar age group. They found that among the cabbies, the back of the hippocampus, the part of the brain associated with spatial memory, was larger than it was in the comparison group. It seemed the expansion came at the expense of the front of the hippocampus, which was smaller than normal. Taxi drivers in London are renowned for their encyclopaedic knowledge of the streets. They spend an average of two years learning the layout of the city's roads before taking a test to get their licenses.