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Ask a Neuroscientist: Can we stop brain pruning in childhood?

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David Eagleman
Dr. David Eagleman is a neuroscientist at Baylor College of Medicine in Houston.
Courtesy of Sharon Steinmann

You wanted to hear more science-related material, and given that this week is Brain Awareness Week, we thought it would be a good time to launch what is going to be an occasional series called 'Ask a Neuroscientist.'

We're asking audience-submitted questions to David Eagleman, a neuroscientist at Baylor College of Medicine in Houston.

Julie in Ramsey wanted to know more about how we prune extra brain connections in childhood. She wonders: Can we stop that pruning as a way to increase brain function or would that just make us all evil geniuses?

David Eagleman: "Well, if you stop the pruning, you stop the learning. What happens is the brain overproduces connections in the embryo and in the newborn, and experience with the world trims those connections. And this trimming happens in a 'survival of the fittest' manner, so those connections get used, get strengthened... and those that are not used are lost. And so in the end, the current state of your brain represents what has been exposed from a much more overgrown garden that you started with. You can think of this the way Michelangelo exposed David from the block of marble. So, the answer to the specific question is you would not want to stop the pruning because that's what makes you who you are from your experience with the world

Tom Weber: So, less is more, in this case?

Eagleman: That's right because it's more specific.

Weber: That's interesting because the logical way of thinking about that would be 'more connection means a better brain.'

Eagleman: Well, more roadways through the field doesn't make a better transportation department. What you want is one very good roadway that connects two houses.