Cabbies in Britain have the knowledge of 25000 London streets, the difficult layouts and 20,000 landmarks on their finger tips.
Indeed, it is surprising to know how the brains of those who pass the immensely tough series of exams to become British cabbies actually have space in their gray matter to accommodate and remember all those routes.
Research has shown that such information gets imprinted in their brains and the training actually increases their memory and spatial navigation.
Out of the many applicants who aspire to become cabbies in Britain, only 50% of the candidates actually clear the exam.
During the study, researchers studied the brain scans of the candidates who cleared the exam as well as those who did not.
There were no differences observed in the brains of the participants either in structure or memory at the time of training.
However, MRI performed four years later showed an increase in brain structure and memory among the qualified drivers. There was an increase in gray matter in the posterior hippocampus, or the back part of the hippocampus, whereas among the non-taxi drivers or trainees who had failed the exams there were no such changes.
Study researcher Eleanor Maguire of University College London said, "The human brain remains 'plastic' even in adult life, allowing it to adapt when we learn new tasks. By following the trainee taxi drivers over time as they acquired or failed to acquire 'the knowledge, 'we have seen directly and within individuals how the structure of the hippocampus can change with external stimulation."