Adult Brains Grow From Specialist Use 260
Xemu writes "Researchers at University College of London's Institute of Neurology have discovered that taxi drivers grow more brain cells in the area associated with memory. Dr Eleanor Maguire says, 'We believe the brain increased in gray matter volume because of the huge amount of data memorized.' She warns against the use of GPS and says it will possibly affect the brain changes seen in this study. This research is the first to show that the brains of adults can grow in response to specialist use." London cabbies, unlike their American counterparts, have to learn the layout of streets and the locations of thousands of places of interest in order to get a license.
London cabbies... (Score:5, Informative)
london streets (Score:3, Informative)
London is also harder to get around, due to the way street names in London work.
Old news for nerds? (Score:5, Informative)
Re:Old news for nerds? (Score:3, Informative)
The taxi drivers have a 20% reduction in anterior hippocampus. And
a 7-8% increase in posterior hippocampus.
Therefore the brain grows from experience!
http://www.pnas.org/cgi/content/full/97/8/4398/F2 [pnas.org]
Then they went on to show a correlation with time as a taxi driver,
but it was only significant if they removed one outlier, a process
that COULD NOT POSSIBLY HAVE BEEN important to their statistical
finding.
http://www.pnas.org/cgi/content/full/97/8/4398 [pnas.org]
That part of the brain has neurons that are selectively active
for the spatial position of the body in rats and Rhesus monkeys. So
it would not be surprising to find it responded to taxi driving
experience. But the surprising thing is the much larger reduction in
anterior hippocampal volume is being ignored...
I am totally in favor of our new GPS automatic map making
overlords!
Spatial aspect is important (Score:3, Informative)
The original idea was that the hippocampus holds a map of spatial environments, and so if someone has a very large amount of spatial knowledge, maybe their hippocampal anatomy will reflect that. This hypothesis is supported by this evidence (that lab has been doing these studies for years, not sure why this is claimed to be so new, except perhaps the control subjects who were bus drivers in London, reducing one potential confound). It should be noted that lately it has been shown that there is a very robust spatial code outside of the hippocampus (and feeding into it) so it appears to not be quite as simple as the hippocampus just holding a map.
Now to your questions. Names, stats, and details are semantic memory, not episodic memory, and are therefore not directly related to the hippocampus (except that all semantic memory appears to start off as episodic memorys, which are slowly re-coded, if you like, into just memory of the facts and not the specific episode where you learned the facts). So if you were constantly learning large amounts of new such data, perhaps you'd see such growth in the hippocampus, but merely having it all memorized would be relying on storage out in neocortex, not the hippocampus.
As the hippocampus (specifically the dentate gyrus, one part of it) is one of the few regions known to constantly be producing new cells, it is expected that experience might cause changes in size there. In other parts of cortex it would be more surprising (to me, at least) if there was a significant change in number of neurons. There the changes are more likely to be structural: neurons making new connections with other, existing neurons.
In summary:
hippocampus = spatial information and acquisition of new memories
neocortex = use and storage of existing knowledge
Re:London cabbies vs American cabbies (Score:3, Informative)
Anyway, as long as we're on anecdotes, when I was in Japan, I asked the cab driver to take me to a well-known club, even using what Japanese I knew, plus a Japanese accent with my English (which actually works better than trying to speak Japanese in many situations). Apparently the language barrier was too steep, so I just showed him the flier with the map all written in Japanese. Instead of looking at it, he just stopped in the middle of a busy road and told us to get out. At least I think he said to get out.. I didn't really understand what he was saying, but the automatically opening doors sort of gave the impression he wanted us out. In hindsight I suppose it's possible he'd spotted some gravel or something on the side of the road and he wanted us to retrieve for him.
Anyway, we just grabbed the next taxi we saw, and the driver was much more helpful.
It's not like we were in some back woods villiage either -- we were in Yokohama, which is a fairly big tourist area.
Re:Cause or Effect? (Score:2, Informative)
I've got TomTom Navigator installed on my ppc phone, and used it all the time when I first started driving so I could memorize the order of the streets, and see dead ends and turns before I got to them.
Nowadays, I only ever even turn it on if a: I'm driving
In those two instances, having a GPS is a wonderful thing.
Usually, if I don't know how to get somewhere, I just ask my passenger for the best route. People know where they're going.
I didn't rely on the gps initially, I was using it as extended vision, I guess. Now that I've learned all that stuff, it only ever gets used if I honestly know nothing around me.
Plus, there are certain cities and jurisdictions in the denver metro area that decided they don't want to use the hundred block system, and start all over from zero, which