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.

Migrants rescued off Italy coast

Some 12,000 people have arrived in Lampedusa since January

Italian vessels have rescued at least 250 would-be migrants from boats and vessels off the coast of Italy.

The navy rescued at least 175 people, believed to be from Eritrea, Ethiopia and Somalia from three vessels, 190km (120 miles) south of Lampedusa island.

A further 72 people – including seven women and a child – were rescued from a rubber dinghy by the coastguard.

Local politicians say Lampedusa is facing a crisis with 12,000 would-be migrants brought ashore since January.

Dangerous journey

The Italian navy agreed to rescue those onboard the three vessels after they ran out of fuel and water in Libyan territorial waters.

The UN refugee agency, the UNHCR, had appealed to Malta, Libya and Italy to rescue the stranded vessels.

A UNHCR spokesman told Reuters news agency he believed some 25 women and six children were among those on board.

Those rescued from the dinghy 80km south of Lampedusa included seven women and a child, Italian media report.

Thousands of Africans risk their lives to make the perilous journey each year, many leaving in makeshift vessels from Libya hoping to gain entry to Europe via Italy or Malta.

Last year, according to rights watchdog the Council of Europe, some 51,000 migrants arrived by boat in Italy, Spain, Greece and Malta, many of them asylum seekers and refugees who lack legal avenues to enter Europe.

Emergency services in Italy have warned that crowded holding centres in the country are on the verge of collapse, worsening a state of emergency declared by the Italian government over immigrants.