Ian McGullcress, welcome to the show.

Thank you very much, Alex. Delighted to be here.

Why is the brain separated into two physical hemispheres?

It's a basic and very good and important. physical hemispheres?

It's a basic and very good and important question.

And it's not really discussed very much, but we know that all the brains that we've ever looked at

are divided in this way so it's not a human thing only

and there are three important oddities One is that it's divided at all,

since the power of the brain is to do with making connections.

Secondly, that it's asymmetrical, which is very odd because there's no reason for it to be asymmetrical.

If you just needed more space, you could just produce more space symmetrically you would think.

And the third is that there is a band of fibers at the base of the brain.

But first of all, this is a new thing.

It only started in mammals. Amphibians, reptiles, frogs have brains, birds have

brains that don't have even this body of fibrescholosum. And what's more a lot of the import of the traffic across the corpus

callosum in humans is inhibitory.

So its final effect is to suppress a contral lateral homologue.

In other words, a bit of the other hemisphere that would be its partner if you like.

So these were questions that I thought were interesting and were in parts,

a reason why I started to go into this area.

And I suppose the first thing I have to say is that most people who

don't know about the recent developments and particularly about my work on

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