For those new to CabbieBlog or readers who are slightly forgetful, on Saturdays I’m republishing posts, many going back over a decade. Some will still be very relevant while others have become dated over time. Just think of this post as your weekend paper supplement.

My Enlarged Hippocampus (21.03.09)

London Black Cab drivers are renowned for being ultra-brainy: we are expected to memorise the routes of up to 25,000 different roads in the capital, along with places of interest, important buildings, miscellanea, and we are not given a licence until we have demonstrated we have “The Knowledge”. And boy, can we talk politics and solve the world’s wrongs! With 70 per cent of trainees dropping out along the way and some Knowledge “boys” taking up to five years to qualify. Although your blog author only took 4 years 10 months and 13 days, I wasn’t counting!

Scientists have now discovered that cab drivers have a strong internal sense of direction that in many people is absent. The scientists found the brain area known as the hippocampus was larger than average in cabbies. This area of the brain starts firing neurons like mad as their cab driver owners ruminate on what route to take from A to B.

Researchers at the Wellcome Trust put dozens of cabbies in a brain scanner, asked them to play a computer game recreating London streets and then analysed their brain activity.

“The hippocampus is crucial for navigation and we use it like a ‘satnav’,” Dr Hugo Spiers of the Institute of Behavioural Neuroscience at University College London told the BA Festival of Science in Liverpool. “London taxi drivers have powerful innate satnavs, strengthened by years of experience.”

He identified three types of cells behind the satnav effect: place cells map our location, direction cells tell us which way we are facing and grid cells how far we have travelled.

In addition, it is said that if you can drive in London, you can drive anywhere. One notable London cabbie was Fred Housego an ordinary working-class London Taxi Driver who won the BBC TV programme Mastermind, normally populated by posh lecturers and civil servants, with his amazing memory for random general knowledge, and his ability to memorise his chosen subject for study.

A recent study also found that an enlarged hippocampus might be the reason why people with dementia might not show signs of the condition. “A larger hippocampus may protect these people from the effects of Alzheimer’s disease-related brain changes,” announced Deniz Erten-Lyons, MD, with Oregon Health and Science University in Portland, at the American Academy of Neurology 60th Annual Meeting in Chicago.

So you see CabbieBlog has an amazing brain compared to the rest of humanity, or has Alzheimer’s and is unaware of it . . . now where DID I put my glasses!