How can you grow your brain? You can always follow the example of London taxi cab drivers and memorize a labyrinth of 25,000 city streets as well as thousands of tourist attractions and hot spots.
While many major cities try to simplify driving by arranging streets in user-friendly grids (or identifying streets by sequenced numbers or alphabetized names), London’s streets are particularly random. The maze of streets requires a unique approach for men and women who want to make a living navigating the confusing tangle. To earn their licenses, cab-drivers-in-training spend four years riding around the city on a moped, memorizing streets and routes. Even then, the licensing test is so difficult that only about half of these drivers-in-training actually pass.
Researchers have realized for some time that London cab drivers have larger-than-normal hippocampi, which is the area of the brain responsible for long-term memory and spatial navigation. This raised an important question: Do people born with bigger memory centers tend to do better on the licensing exam and, thus, become cab drivers? Or do cab drivers start out with normal sized hippocampi and experience unusual growth due to the intense memorization?
After following 79 aspiring cab drivers for four years, measuring the growth of their hippocampi with brain scans, researchers now know the answer: London cab drivers appear to start out with normal memory centers that “plump up” to accommodate the demand of their profession.
Boston University’s Howard Eichenbaum, a neurobiologist, summed up the importance of these findings by saying, “It shows you can produce profound changes in the brain with training,” adding, “That’s a big deal.”