Can you exercise bits of your brain?

We posed this question to the brain panel. Katie - So, there are a few areas of the brain where new neurons can form right throughout life and the hippocampus which is involved in memory and learning is one of them. There is evidence that the hippocampus can become bigger as a result of certain experiences. Exercise is one of them. It can help to generate new neurons. Typical example of this is the hippocampus size in London cab drivers and they have to learn the entire London roadway system and pass a complicated test called The Knowledge. Eleanor McGuire, the researcher who's looked at this a lot, has followed a group of successful and unsuccessful taxi driver trainees and she showed that an increase in the posterior hippocampus was associated with those that did pass the test and went on successfully has become the taxi drivers.

Hannah - So, just by training, just by trying to pass this knowledge test and kind of exercising their navigation, spatial reasoning skills by navigating through London in their black cabs, they actually grew one part of the hippocampus. But was this at the expense of another part of the hippocampus or another part of the brain?

Katie - I think it was at the expense of the anterior hippocampus.

Hannah - Which is the region that wasn't involved in this navigation and spatial reasoning kind of skills?

Bill - If you pay attention to a certain kind of activity, you may use more for that and at the expense of something else. Blind people I think use their visual cortex - sighted people would use it for vision and blind people can use part of their visual cortex for other tasks, perhaps auditory tasks.

Katie - Yeah, probably the point is that the brain isn't able to infinitely grow. There are size constraints, but there are also constraints on what you choose to do with your time and we tend to choose to fill our times with the things that we enjoy and the things that we're good at.