The hippocampus, the brain region known to govern memory and spatial navigation, is larger in qualified taxi drivers, new research finds.
Researchers who followed a group of trainee taxi drivers found that mastering "The Knowledge" can alter brain structure.
However, this only occurred in those who successfully qualified after spending up to four years memorizing London's 25,000 streets and numerous landmarks.
Scans revealed they had a greater volume of "grey matter" at the back of the hippocampus. Grey matter consists of the "bodies" of nerve cells and is where neural processing occurs.
Drivers who failed the challenging series of "Knowledge" exams failed to show evidence of the same changes, as did a comparison group of non-taxi drivers.
Lead scientist Professor Eleanor Maguire, from the Wellcome Trust Centre for Neuroimaging at University College London, had previously found enlargement of the hippocampus in London taxi drivers, the BBC reports.
Both studies suggest that the drivers’ brains may have changed to accommodate an internal "map" of London.
The latest research goes a step further, however, and raises questions about "nature versus nurture.”
