The GPS in Our Brains: How We Navigate the World with Our Minds

How we navigate the world is controlled by our brain. Now, though, scientists know exactly which regions of the brain allow us to get from point A to point B. It turns out that there are two brain regions which track the distance to our destination.

In order to learn a bit more about how our brains manage to cope with navigation, the researchers used film footage to create the busy streets of Soho in London inside an MRI scanner. Volunteers were then asked to navigate through the district while their brains were actively monitored. The researchers then analyzed brain activity during the different stages of the journey, which included setting a course for the destination, keeping track of the destination while travelling, and decision making at street junctions.

In the end, the scientists found that activity in the entorhinal cortex, which is a region in the brain essential for navigation and memory, was sensitive to the straight-line distance to the destination when first working out how to get there. During the rest of the journey, though, the posterior hippocampus became active when keeping track of the path needed to reach the destination.

"Our team developed a new strategy for testing navigation and found that the way our brain directs our navigation is more complex than we imagined, calculating two types of distance in separate areas of the brain," said Hugo Spiers, one of the researchers, in a news release.  Not only that, but the study shows why London taxi drivers had an enlarged hippocampus. "Our results indicate that it is the daily demand on processing paths in their posterior hippocampus that leads to the impressive expansion of the grey matter," he said.

The findings shed light on the underlying biology of mental health conditions that affect memory. This could reveal further information about conditions, such as Alzheimer's disease, and could add to further research to create treatments in the future.

The findings are published in the journal Current Biology.