The scientists adapted the Playstation2 game "Getaway" to bring the streets of London into the scanner.
After the scan - and without prior warning - the drivers watched a replay of their performance and reported what they had been thinking at each stage.
"We tried to peel out the common thoughts that taxi drivers tend to have as they drive through the city, and then tie them down to a particular time and place," said Dr Spiers.
The series of scans revealed a complex choreography of brain activity as the taxi drivers responded to different scenarios.
The hippocampus was only active when the taxi drivers initially planned their route, or if they had to completely change their destination during the course of the journey.
The scientists saw activity in a different brain region when the drivers came across an unexpected situation - for example, a blocked-off junction.
Another part of the brain helped taxi drivers to track how close they were to the endpoint of their journey; like a metal detector, its activity increased when they were closer to their goal.
Changes also occurred in brain regions that are important in social behaviour.
Taxi driving is not just about navigation: "Drivers do obsess occasionally about what their customers are thinking," said Dr Spiers.
Animals use a number of different mechanisms to navigate - the Sun's polarized light rays, the Earth's magnetic fields and the position of the stars.
This research provides new information about the specific roles of areas within the brains of expert human navigators.
Transcript from radio show "Something You Should Know" with Mike Carruthers
August 8, 2008
The Crazy Things People Do
Interview with Andrew Williams, author of Are You Crazy?
Andrew Williams:
Approximately 5 million Americans are believed to suffer with face blindness. And face blindness is the inability to recognize people from their faces.
Andrew Williams, author of the book Are You Crazy?...
Individuals who have this cannot recognize their children, their spouses, people they work with; and those people who have it often report that if they stand on their head and look at faces upside-down, it's easier for them to recognize the individual.
It just may be that we all have something weird about us so maybe we need to be a little more understanding of people who have things like face blindness or something called pica.
Pica, or P I C A, this is eating foods that are not usually food items: coins, ash, cigarette butts, soap and coffee grounds.
It often starts in childhood, says Andrew, when kids start putting strange things in their mouths and an extreme case of pica…
It happened just last year where a 62-year-old man went to the emergency room because he had a total of 360 coins in his stomach.
And speaking of eating things…
There are individuals who are afraid to eat what they refer to as concealed food. And that is food that they can't see the inside of. So something like ravioli, they would be afraid to eat it because they don't know what's inside.
At somethingyoushouldknow.net I'm Mike Carruthers and that's Something You Should Know.
