Dr. Matt Walker

That was the suggestion.

Could you pop those memories out of the biography of that individual and save them the trauma?

I would argue that's not really what you want to do, because let's say that I am I have a trauma experience where I was walking home at night from the sleep laboratory late at night and I was coming down the kind of an alley to take a shortcut and someone sticks me up with a gun, maybe some violence.

I don't want to remove that memory.

I would like to remove the trauma response associated with that memory.

But I would argue for me as an organism, it's still very important for me to remember that that alley was associated with a bad experience and I should forego going down that very same route again.

I want to hold on to the memory, the information.

I want to let go of the emotion.

I want to sleep to remember, and I want to sleep to forget.

And I'll come on to why I think that's relevant to PTSD when we perhaps speak about that condition, and it's very, very relevant.

But coming back to REM sleep,

We looked back in the literature to see if we could find signs that REM sleep had this relationship with even just your basic emotional reactivity.

And there was some wonderful work by a gentleman that you will know from Stanford, probably one of the founding fathers of modern day sleep research, a gentleman called William Dement.

He was not, but he was well up there in terms of understanding both sort of what its term was and also what its function was.

He, legend as he was, very early on, this was probably in the 60s, he would take individuals because we didn't really have the first published report of these two types of sleep, of REM and non-REM, until they collected the data or found the data in 1953.

It was published in 1954.

So in other words, we discovered...

that even up to then, prior to then, we just thought sleep was sleep.

We didn't have any knowledge that these different stages.

So in the same year that Francis Crick unveiled this incredible helical structure that was called a DNA strand, we also discovered the different stages of sleep.