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Sunday, December 5, 2021

Cabbies May Unlock Alzheimer’s Secret

Find out why researchers are studying London cab drivers’ brains to learn more about dementia.   

If you hop into one of London’s iconic black taxis, the driver won’t chart a course to your destination with GPS. That’s because every cabbie in this sprawling city since 1865 has had to pass a test called “the Knowledge.” It may be the most difficult piece of memorization on Earth. The region of the brain known as the hippocampus, which shrinks in Alzheimer’s patients, apparently increases in size for cab drivers the longer they are on the job.

Why London Cabbies Are Different

The cluster of exams that make up the Knowledge take three or even four years to finish. Cabbies must know how to navigate 26,000 streets encompassing a six-mile circle around Charing Cross, the heart of London, in order to earn full licensure and a coveted green badge. 

“London cabbies have remarkable brains,” says Hugo Spiers, lead author of the Taxi Brains study underway at University College London. He is building on research done more than 20 years ago by Irish neuroscientist Eleanor Maguire that demonstrated positive changes in taxi drivers’ brains resulting from learning the Knowledge. 

Train Your Brain

If you’ve decided you’d like to delve deeper into this method of brain training, you can! London driver Rob Lordon has written the book The Knowledge: Train Your Brain Like a Cabbie. Or you can check out his blog on the subject: View From the Mirror, A Cabbie’s London. 
“We don’t know much about how taxi drivers use their hippocampus during route planning,” says Spiers. “And how do they use other brain regions to solve the task of navigating 26,000 streets? Can we explain why they might be quick to plan out one route and take a while to think out another one? It’s something we need to know more about.”

Researchers hope that by taking MRIs of cabbies’ brains while they are asked to plot out 120 routes in their minds, they will find a way to detect dementia sooner and begin treatment earlier. In return, the cabbies get $40 and an MRI photo of their brain. If you think that’s scant reward for their efforts, you’d be right. Many have personal reasons for participating.

Meet A Participant

Cabbie Matt Newton’s father died of dementia a couple of years ago. “I know what a devastating disease it is for the person (who has it) and the family,” he says. “It was only a few hours of my time, so I was happy to help.” Newton, 44, has been a cabbie since 2016. In addition to route mapping, the cabbies are asked to play Sea Hero Quest, a video game requiring players to use complex spatial navigation. 

“I actually enjoyed studying the Knowledge,” says Newton, “but it was extremely difficult. Most people give up. I studied 12 hours a day, seven days a week for three and a half years.” Newton was a network analyst for two decades before changing careers. He now earns between $50,000 and $100,000 a year, depending on how many hours he puts in behind the wheel.

“I started out learning the ‘Blue Book’ — a set of 320 runs between various points in London,” he says. “I started calling up 80 of these runs every day in my head, then driving the runs on a scooter. I learned hospital runs, theater runs, football runs, and ‘no traffic light’ runs before I applied to be a taxi driver.”

After passing an initial written test, Newton progressed to the portion that would earn him the designation of “black cabbie.” He was required to pass an oral examination every 56 days, reciting the streets he’d take to cover four different routes between points in London. When he’d passed that hurdle, he was called in to the examiner’s office every 28 days, and then every 21 days, for testing.

“At each point, if you fail you go back to the previous level,” he says.

Ideal Study Subjects

London cabbies make ideal participants because there is no other professional group quite like them, especially in the field of spatial navigation,” says researcher Chris Gahnstrom. “They’re a large group of expert navigators who have all had to learn an immense amount of similar information that they are required to use on a daily basis.”

The Taxi Brains researchers are hopeful they can pinpoint the particular subregions of the hippocampus that are most altered in the brains of the 30 cabbies in the study. Results will be passed on to Alzheimer’s Research UK and preliminary findings should appear sometime in the summer of 2022. 


Blog posting provided by Society of Certified Senior Advisors