Dr Sutapa Mukherjee

and trying to help us see how we can move forward.

And you're exactly right.

A lot of people have great ideas in the shower after they've had a good sleep.

I mean, I think there are different researchers that have tried to look at that.

But sleep's actually really hard to study because, I mean, obviously if we are monitoring someone's brainwaves, we can't have them in an MRI machine trying to see which part of the brain is lighting up because the noise of the MRI scan will stop them from sleeping.

Yes, and it's actually really hard to look at some of those things of what exactly is happening.

There have been, you know, some animal studies where they've really tried to look at the different parts of the brain that are active.

And, you know, the best that we have is the electroencephalogram, which we've got very, very clear.

clear signals in the different stages of sleep.

So we can actually see when people are in slow wave sleep or they're in REM sleep or they're in stage one sleep.

We can see the arousals because arousals from sleep or waking up, if you like, are a normal part of sleep.

And so we can pick all of those things on the electroencephalogram.

And so people have done, you know, tried to do studies where, for example, when they see someone's in a certain stage of sleep, they'll ring a bell.

And so you've all probably experienced when you're asleep and...

In the stages of sleep, stage one and two, and even in REM sleep, you can often arouse quite easily to a noise.

But if you happen to be in slow-wave sleep...

And you might not hear a noise.

And I have been on call for the sleep laboratory and the staff in the sleep lab have had to try to get in touch with me at night.

And if they happen to ring me and I'm in slow wave sleep, they'll often say, we rang you at 3 a.m.

and you didn't answer.