London cab drivers had a reshaped memory center

Researchers at University College London scanned the brains of London taxi drivers, who must memorize thousands of streets and landmarks to pass a famously difficult licensing exam known as the Knowledge, and compared them with people who did not drive taxis.

The posterior hippocampus, a region known to store spatial maps, was significantly larger in the taxi drivers than in the comparison group, and its size increased with the number of years a person had spent driving, in a group with up to 42 years of experience behind the wheel.

The anterior hippocampus told the opposite story, slightly smaller in drivers, suggesting the brain was trading space between regions rather than simply growing larger overall, and that intensive navigation experience could reshape an adult brain once thought to be fixed after childhood. The study could not rule out that people with an unusually capable hippocampus to begin with were the ones drawn to taxi driving in the first place.

A city, memorized into the brain's shape.