Becoming a licensed London taxi driver is not easy. Trainees must acquire “the Knowledge” — memorizing 25,000 streets, their layout, and 20,000 landmarks. Learning this takes three to four years, culminating in a series of exams that only about half of trainees pass.

Eleanor Maguire and Katherine Woollett, University College London, UK, have studied the brain structure of trainee taxi drivers and non-taxi driver controls during this learning process. At the start of the study, participants showed no differences in either brain structure or memory. Those who qualified experienced increased gray matter in their posterior hippocampi and concomitant changes to their memory profile. The hippocampus plays important roles in memory and spatial navigation. Changes were not observed in those trainees who failed to qualify, or in the non-taxi driver controls.

This demonstrates that the human brain remains plastic even in adult life. This is encouraging for life-long learning and rehabilitation after brain injury.

• Acquiring “the Knowledge” of London’s Layout Drives Structural Brain Changes
  K. Woollett, E. A. Maguire,
  Current Biology 2011.
  DOI: 10.1016/j.cub.2011.11.018