When scientists analyzed the brains of taxi drivers in London, they
found that the hippocampus—a region of the brain involved in spatial
memory—was significantly larger in their subjects than in non–taxi
drivers. Even more fascinating, the hippocampus decreased in size
when a driver retired. Like the muscles of the body responding to
regular weight training, particular regions of the brain adapt as they
are used and atrophy as they are abandoned.
Of course, the importance of repetition in establishing habits was
recognized long before neuroscientists began poking around. In 1860,
the English philosopher George H. Lewes noted, “In learning to speak
a new language, to play on a musical instrument, or to perform
unaccustomed movements, great difficulty is felt, because the channels
through which each sensation has to pass have not become
established; but no sooner has frequent repetition cut a pathway, than
this difficulty vanishes; the actions become so automatic that they can
be performed while the mind is otherwise engaged.” Both common
sense and scientific evidence agree: repetition is a form of change.
cut a pathway common sense otherwise engaged