If you are at all interested in how the brain or mind works, for example if you study psychology, neuroscience or philosophy of mind, then you know should about grid cells. I know I said that already about place cells, but they are pretty amazing aren’t they? Well, as amazing as place cells are, grid cells are even more remarkable.
In 2000 and again in 2006, Professor Eleanor Maguire of the Wellcome Trust Centre for Neuroimaging published papers showing that London taxi drivers brains are structurally different from other people’s. If you haven’t had the pleasure of riding in a black cab, this may seem like a rather strange topic for study (certainly it must have seemed that way to the judges of the Ignobel Prize, which Eleanor won for the first of these studies). In fact, it was a very sensible investigation which has proved to be very influential: the hippocampus is critical for the formation of new long-term memories and plays an important part in the way we find our way around – it is thought to provide a “cognitive map“. In London, licensed drivers have to undergo several years of training – the Knowledge – until they know the roads and landmarks of the city like the back of their hands. When you hail a London cab, you can rely on the driver getting you where you want to go however obscure; it’s not yet certain, but it seems this level of expertise and experience changes the structure of their brains and especially the shape and size of the hippocampus.
On a recent trip to London, I took the opportunity to talk to my driver about the training and his own approach to learning and memory. He admitted that the Knowledge had taken over his life, and had been so stressful that at times he had chuck all his books and maps in the bin, only for his wife to rescue them, he also revealed some interesting intuitions about how memory works.
I thank the driver (whose permission I asked) – his name is, I think, John Law – unfortunately the clip where I thanked him did not record properly, and I am hoping someone will let me know the correct name, so I can append a credit to the video.