This particular publication may add new data, but this basic finding about London cabbies is years old - it won the Ig Nobel prize years ago. Not sure if the previous work was by the same research group or a different one.
No mention of that in the article, of course, because press-release science exists in a timeless vacuum independent of context or references.
The big advance here is that the current study shows that the brain change occurred directly as a result of the learning. Previous studies had a weakness in that they only looked at brain size well after the learning had occurred; raising the possibility that people with bigger hippocampi choose to become taxi drivers, or are the only people who pass the test.
So the new study established causation, extending our knowledge beyond the correlation.
To become a cab driver in London, you have to acquire "The Knowledge," which is their fancy way of saying that you have to memorize all the streets in London. It's quite a process that takes most three to four years to complete.
Crazy. Any bets on for how long they are going to continue this practice? Seems almost as redundant as to teach them how to drive a horse buggy just for the time their engine is dead.
I remain unconvinced that it's crazy. I've been driven in London by a cabbie when there are unexpected road closures and diversions, and there is absolutely no doubt that he did better than any existing system at getting me where I wanted to go efficiently despite the problems.
GPS and SatNav is currently no solution for the streets of London. Remember, it's been there a long time, and initially grew without the existence of cars.
I've been driven by cab in London to an address we later found was on the same physical street, it just changed name halfway. The folks at the destination laughed and said that while the cabbie should have just driven straight down the street, his actual route took us about four times the distance it should have...
It seems that The Knowledge isn't necessarily implemented for The Punters :)
There's knowing the quickest route to take and then there's taking the longest route you can get away with. Two different problems with the same data set.
It might be also a cultural thing. Brits might be expecting a more "perfect" service while most NYC'ians might be fine with a more improvisation'al service for most of the time and when in need hire just a black cab/car service.
there are cabs, in addition to the famous cabbies, which are half priced, and located in almost every second street. However, you will have to call and order their services, as they are not allowed to pick up random passengers from the street.
So, memorization will change brain structure. Interesting.
I'd also bet that people who for various reasons had to memorize a lot (for example, if you weren't ever taught to read either now or years ago when it wasn't a common skill) also have different brain structure.
"The Knowledge" is not purely about memorization, there is also route planning to consider. Potential cabbies are not merely asked to quote street names and tell you where they are, they are also required to plan routes from point to point given various limitations such as road closures, etc.
It's not clear that the memorization alone would cause such changes in the brain's structure.
In addition to just memorizing facts, they are building a mental structure for all the connections within the city. I wonder if learning the structure of any large system would have the same effect? For example, a large software system, the economic system, or the political system -- where you understand the relationships of all the political players.
Perhaps the political system, or a complex ecosystem with a lot of relationships, but I think software and economic systems are generally much less complex than London. The thing about a city like London is it's pretty much 'incompressible' data. If you want to learn New York, large chunks of it compress by saying things like "the roads are mostly a grid", "these streets are numbered sequentially", etc. London doesn't show that kind of patterned, designed structure that allows other complex systems like software systems to be learned. Imagine trying to learn Unix when anything that would be referenced by a number is referenced by its own name.
Also cabbies need to know traffic patterns for the city to get around it quickly, which means in principle you're learning what the traffic is likely to be like on every road on every day of the week. That's a lot more compressible though.
I would assume that it is simply the amount of thought and focus that is required to memorize thousands of streets that would cause these increases. I wish there was a control or a group of people that were studying something besides memorization to see if there was truly a difference. The time frame here is 3 to 4 years.
Here you go: "Musical training-induced functional reorganization of the adult brain: functional magnetic resonance imaging and transcranial magnetic stimulation study on amateur string players."[1]
They went over this phenomena in a 60 minutes piece that chronicles are far more advanced version of this, where the people studied actually remembered a highly detailed version of their entire lives. They call it Superior Autobiographical Memory and I strongly urge people to watch it, the details of the things remembered from 30+ years ago are shocking.
It's a point of pride amongst cabbies to have the got past the hurdle of attaining 'the knowledge'. And my guess is that their union will be able to pressure the taxi licensing body not to reduce the hurdle, since that is what keeps the 'riff-raff' out.
I'm not a neurologist but I believe that not all learning is the same. In this case they were specifically learning spatial mapping (and possibly manipulation and reasoning). The study doesn't say anything about linguistic learning, which happens in a different part of the brain.
I would imagine only if you were fluent in it. I bet these cabbies have to lice And breathe this information. You need not just a pile of facts, but the bigger picture: it has to be instinctive.
The article says this offers encouragement to adults wanting to learn later in life. Bullocks. The article simply shows that any claims about the brain's plasticity being "frozen" after a certain age were incorrect (or overstated). I'm sure "old" people have been learning "The Knowledge" successfully for years now. They weren't worried about inaccurate claims of low brain plasticity ... they had a test to study for.
We already had the "encouragement" because people have been passing the test. We didn't need to wait for the scientists to catch up. The finding did not uncover any new ability ... it merely helped explain a capability we should have already observed in terms of increased grey matter.
I agree! Science never surprises us; all it does is reinforce our prejudices and common sense, so what's the point of funding it? We already know everything it would tell us.
No mention of that in the article, of course, because press-release science exists in a timeless vacuum independent of context or references.
EDIT: Not surprisingly, the folks at the Annals of Improbable Research are better science journalists than average: http://www.improbable.com/2011/12/09/taxi-driver-brains-a-fu...