Taxi drivers ‘have brain sat-nav’

The knowledge: London cabbies are famous for knowing their way around

Scientists have uncovered evidence for an inbuilt “sat-nav” system in the brains of London taxi drivers.

They used magnetic scanners to explore the brain activity of taxi drivers as they navigated their way through a virtual simulation of London’s streets.

Different brain regions were activated as they considered route options, spotted familiar landmarks or thought about their customers.

The research was presented at this week’s BA Science Festival.

Earlier studies had shown that taxi drivers have a larger hippocampus – a region of the brain that plays an important role in navigation.

Their brains even “grow on the job” as they build up detailed information needed to find their way around London’s labyrinth of streets – information famously referred to as “The Knowledge”.

“We were keen to go beyond brain structure – and see what activity is going on inside the brains of taxi drivers while they are doing their job,” said Dr Hugo Spiers from University College London.

The scientists used functional magnetic resonance imaging (fMRI) to obtain “minute by minute” brain images from 20 taxi drivers as they delivered customers to destinations on “virtual jobs”.

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.

‘Climate crisis’ needs brain gain

The UK alone has invested more than half-a-billion pounds in the LHC

The most brilliant minds should be directed to solving Earth’s greatest challenges, such as climate change, says Sir David King.

The former UK chief scientist will use his presidential address at the BA Science Festival to call for a gear-change among innovative thinkers.

He will suggest that less time and money is spent on endeavors such as space exploration and particle physics.

He says population growth and poverty in Africa also demand attention.

“The challenges of the 21st Century are qualitatively different from anything that we’ve had to face up to before,” he told reporters before the opening of the festival, which is being held this year in Liverpool.

“This requires a re-think of priorities in science and technology and a redrawing of our society’s inner attitudes towards science and technology.”

Huge expense

Sir David’s remarks will be controversial because they are being made just as the UK is about to celebrate its participation in the Large Hadron Collider, the world’s biggest physics experiment.

The Collider, built at the Cern laboratory under the Swiss-French border, is starting full operations this Wednesday.

It will seek to understand the building blocks of matter, and, in particular, try to find a mechanism that can explain why matter has mass.

This international venture is extremely expensive, however. The UK alone has contributed more than £500m to the LHC – the largest sum of money to date invested by a UK government in a single scientific project.

Sir David said it was time such funding – and the brains it supports – were pushed to answering more pressing concerns.

“It’s all very well to demonstrate that we can land a craft on Mars, it’s all very well to discover whether or not there is a Higgs boson (a potential mass mechanism); but I would just suggest that we need to pull people towards perhaps the bigger challenges where the outcome for our civilization is really crucial.”

Big ideas

Chief among these challenges for Sir David is the issue of climate change. When he was the government’s top scientist, he made the famous remark that the threat from climate change was bigger than the threat posed by terrorism.

He said alternatives to fossil fuels were desperately needed to power a civilization that would number some nine billion people by mid-century – nine billion people who would all expect a high standard of living.

“We will have to re-gear our thinking because our entire civilization depends on energy production, and we have been producing that energy very largely through fossil fuels; and we will have to remove our dependence from fossil fuels virtually completely, or we will have to learn how to capture carbon dioxide from fossil fuel usage,” he said.

Finding and exploiting clean energy sources was now imperative, he said; and Sir David questioned whether the spending on particle physics research in the shape of Cern’s Large Hadron Collider was the best route to that goal.

He even doubted whether Cern’s greatest invention was an outcome that could only have come from an institution that pursued so-called “blue skies research”.

“People say to me: ‘well what about the world wide web? That emerged from Cern’. Brilliant. Tim Berners Lee was the person who invented that. What if Tim Berners Lee had been working in a solar [power] laboratory? Perhaps he would have done it there as well. The spin-out would have come from the brilliant individual.”