Itβs not just repeated physical actions that can rewire our brains. Purely mental activity can also alter our neural circuitry, sometimes in far-reaching ways. In the late 1990s, a group of British researchers scanned the brains of sixteen London cab drivers who had between two and forty-two years of experience behind the wheel. When they compared the scans with those of a control group, they found that the taxi driversβ posterior hippocampus, a part of the brain that plays a key role in storing spatial representation won much larger than normal.
Excerpt from: The Shallows: How the internet is changing the way we think, read and remember by Nicholas Carr