The many maps of the brain

Your brain has at least four different senses of location – and perhaps as many as 10. And each is different, according to new research from the Kavli Institute for Systems Neuroscience, at the Norwegian University of Science and Technology.

The findings, published in the 6 December 2012 issue of Nature, show that rather than just a single sense of location, the brain has a number of “modules” dedicated to self-location. Each module contains its own internal GPS-like mapping system that keeps track of movement, and has other characteristics that also distinguishes one from another.

"We have at least four senses of location," says Edvard Moser, director of the Kavli Institute. "Each has its own scale for representing the external environment, ranging from very fine to very coarse. The different modules react differently to changes in the environment. Some may scale the brain’s inner map to the surroundings, others do not. And they operate independently of each other in several ways."

This is also the first time that researchers have been able to show that a part of the brain that does not directly respond to sensory input, called the association cortex, is organized into modules. The research was conducted using rats.

How Driving a Taxi Changes London Cabbies’ Brains

Every black-cab driver in central London has to have “The Knowledge” — a memorized map of the capital, including some 25,000 streets and thousands of landmarks, right down to the order of theaters on Shaftesbury Avenue.

It’s a brutal learning process that can take three to four years to complete, with a final test — the Knowledge of London Examination System — that often takes 12 attempts to pass. Even then, ultimately only half of the trainee cabbies ace the exam.

According to a report published in the journal Current Biology, successfully learning this mental atlas of London’s spaghetti streets causes structural changes in the brain, affects memory and creates a greater volume of nerve cells in the brain’s hippocampus.