people get into your cab you're just dipping and out of people's lives every 15 minutes how's your day going forward into slime Square lead by Clyde them place the knowledge is the test every London cabbie has to take that's 26 000 roads and a thousand routes connecting everyone lift into Buckingham Palace Road forwarding to Buckingham gate and you have to commit every journey to memory before you join a very select band when the exam is ending me my badge you said to me congratulations well done this is the equivalent of doing a degree in law and I said to him I wish you'd have sold me that three years ago because uh I think I'd have preferred the degree in law to be honest I could be an America the voltage but instead John has been wired up to a super powerful MRI scanner in the bowels of UCL for a groundbreaking scientific experiment so we are testing London taxi drivers and seeing what's so special about their brains and we're also looking at how they plan routes throughout London so we've designed an experiment where there we have 120 different routes and we're looking at their brain activity while they're doing so all right well done perfect would you like to continue with a technical scan yeah more than 30 taxi drivers have volunteered to be scanned in an MRI and to have their brain function measured while working out routes across London at the same time answering the questions while you're in there trying to stay still in a MRI tube for an hour yeah it was interesting to be fair so we have you know new technology now and actually ways in which we can take a much more high resolution image and in particular we're looking at the hippocampus which in taxidermists is a very special brain area because it has this incredible thing of it grows larger but what's even more fascinating is that this structural change it's in relation to how many years you've spent as a taxi driver so it's not simply you know learning all this stuff it's actually implementing it over years and years that causes a larger and larger change in your brain structure and this is one of the maybe the kind of strongest example of adult human brain plasticity that the human brain can change even into adulthood no matter when you take up a new skill such as becoming a taxi driver which is something amazing and it's something that we can really only look at the taxi drivers for so with today's technology we're able to look in a lot higher detail so we can look at subfields and substructures of hippocampus to really understand what's going on which was impossible before I suppose there we sort of dyed our way through it he's learning the what we call oranges and lemons and then there's a few side roads that join them all up and that's all you do as long as you know where north south east and west is there is real urgency in this project because the researchers believe that unlocking taxi drivers special skills are a way to finding out more about dementia there's a huge problem facing society which is essentially that the population creeps go growing older and older and we still don't have a cure for dementia and Alzheimer's disease and really it's not enough is known about kind of how and why this happens so we're hoping by getting a much better understanding of how this brain region actually functions and how it can change that that will lead to new breakthroughs and discoveries and how it can we can cure Alzheimer's disease down the line once the atrophy has started people with ad Alzheimer's dementia are no longer able to navigate specifically familiar environments so they tend to get lost you know around their own homes in their local Village in their local area and that is one one of the first signs that this onset has occurred I know a couple of friends whose parents or uncles have got they've been touched with the main children so yeah I'll give it a go yeah I think people should do their bit really yeah I'm sure images we're acquiring with these taxi drivers is not how the hippocampus declines so that would be the more clinical side of Alzheimer's research but actually how the hippocampus grows it doesn't matter how many taxi drivers we've tested it's still exciting to you know pull up that high resolution image get a look at their hippocampus and actually see that we can see the individual folds of the hippocampi which was never possible before the ideas for this project we've been sitting on for a while we had these you know mathematical models of planning that we wanted to test with the taxi drivers but simply we didn't have the funding to do so and this is quite you know a common problem in science as well is that funding is scarce ideas or not an Ordnance survey agreed to fund this really exciting research project so actually being able to match up a good research question with not just a funding body but a funding body that actually makes sense for the project as well we really are kind of testing Maps right we're testing the taxi drivers on on their knowledge and being able to kind of compute very quickly Roots across the giant map that is the Streets of London simply put this project wouldn't have been possible without Ordinance survey and yeah so very exciting I thank you so very much [Music] thank you