Memory Lanes - Brain Imaging and Taxi Drivers

Taxi drivers in London undergo extensive training that typically involves 2-4 years. This places a heavy demand on the hippocampus, a region in the brain strongly associated with spatial learning.

Taxi drivers in London undergo extensive training that typically involves 2-4 years. This places a heavy demand on the hippocampus, a region in the brain strongly associated with spatial learning.

Studies by Eleanor Maguire and colleagues at University College London in the year 2000 and 2006 looked at the effects of practice on the structure of the brain. Among the individuals studied were bus drivers, taxi drivers, and regular drivers. Individuals had different levels of experience in driving in London and the groups sought to determine whether these experiences affected the structures of their brain. In this animation, we compare the driving performance of some of these drivers and examine whether their driving experience has had any effects on their brain. Rollover the cars below to read a profile of each driver. Once you have read the profiles, choose a destination and wait to see who arrives first. Who do you think will be the quickest? Barry Styles - 37 years old. Barry has been driving a taxi cab for fifteen years. Raj Patel - 38 years old. Has been driving the number 65 Kingston to Ealing bus route through London for the past fifteen years. Robert Lewis - 38 years old. Robert has worked as an administrator in Guildhall for the past sixteen years. He takes the tube to work every morning. David Smith - 22 years old. Last January, after three years studying “The Knowledge,” an in depth study of London street routes and places of interest, David acquired his license. He has been regularly driving a taxi ever since. Unsurprisingly, the two taxi drivers got to their destinations very quickly. London taxi drivers are required to have an in-depth knowledge of the city streets and they clearly know their way round. Although Raj has been a bus-driver for 15 years, he has been driving the same bus route and actually does not know the London streets all that well. Similarly, Robert knows very little about London’s streets. Maguire and her colleagues were curious to know whether these differences in driving experience had an effect on the brain. They recruited drivers for a brain imaging study and looked for differences in size between different structural areas. The hippocampus is particularly important to spatial learning and the research team expected to find some differences in hippocampal volume. Drag a member from each group into the scanner. Once you have selected your participants, hit “perform subtraction”. Choose two groups to compare their brains. [Note: No data is available to compare regular drivers and bus drivers, but all other combinations are possible.] Taxi drivers in London are required to learn “The Knowledge,” extensive training that typically involves 2-4 years study and the learning the layout of some 25,000 city streets. This places a heavy demand on the hippocampus, a region in the brain strongly associated with spatial learning. The size of the hippocampus in the taxi drivers is larger than in either of the other driving groups. Moreover, the drivers who had been driving the longest showed the largest increases in hippocampal volume. This provides a clear demonstration that excessive practice can change the structure of your brain, even when that practice come relatively late in life. Subsequent studies of athletes and musicians (who also train extensively in one particular area) show similar increases in brain volume. We do not yet know what is the cause of these structural increase – it may be driven by growth in the size of existing neurons, by neurogenesis (the growth of new neurons), or by arborization (the branching out of axons and dendrites). We do know, however, that our brains are remarkably ‘plastic’ structures that can undergo significant changes in response to the demands placed upon them.