EGRU-blog

Maguire E.A., Gadian D.G., Johnsrude I.S., Good C.D., Ashburner J., Frackowiak R.S.J., Frith C.D. (2000) Navigation-related structural change in the hippocampi of taxi drivers Proceedings of the National Academy of Sciences 97:4397-4403 doi: 10.1073/pnas070039597

This paper is not the most recent one, but it is a really grabbing study that might not be known by each of us.

Taxi drivers in London need to have well developed navigation skills to be able to orientate between thousands of places in this big, crowded city. They undergo a very serious (the so called “being on The Knowledge”) training where they acquire navigation ability and they also have to pass a difficult police examination. After these procedures they are supposed to have extended spatial memory. In mammalian brain, the hippocampus is known to be responsible for the spatial memory.

The authors compared taxi drivers’ brains with ordinary humans’ brains. More relevant and independent methods were used for the analyses and both gave the same result. Taxi drivers and control people differed in the volume of the posterior and anterior hippocampus relative to the hippocampus. Their relative hippocampus volume to the total brain was similar. The relative size of the posterior hippocampus was found to be significantly larger while the anterior hippocampus was significantly smaller of taxi drivers’ brain. Further, the relative size of the right posterior hippocampus correlated positively, whereas the size of the right anterior hippocampus correlated negatively with the amount of time spent as a taxi driver. These results support the prediction of the authors that the structural change is rather an acquired feature than a genetic prerequisite of becoming a licensed London taxi driver.

This study is a fascinating example for plasticity and reorganization possibility of human brain even in adulthood, so never give up!