Dr. Matt Walker

And the hinge was so loose, however, that even just the tiniest flick of a challenge, whoosh, you went straight over to the sympathetic.

There was no sweet spot of a tightening where you were nicely balancing between those two states.

And this comes back to something else that we found.

That's you switching flip-flopping back and forth between parasympathetic and sympathetic.

I spoke about the emotional reactivity to negative aversive events, but that's only one half of what we call the affective valence domain.

It's not just that you can have negative emotional reactions.

Of course, you can have positive emotional reactions.

So we did assist the study to that amygdala study.

And we asked, rather than showing you increasingly negative images and how your amygdala would respond much more strongly to those as we provoked it, we then started to show you much more positive, rewarding images.

And because one hypothesis would be that you just simply slide down the scale and you move towards more negative and away from more reward-based reactivity.

Or you could imagine that it's both, that when you are sleep deprived, you are equally excessively reactive to both of those domains.

And what we found was that it was the latter.

that you were very abnormally reactive, overreactive to negative events, but you were equally hypersensitive to very reward based stimuli.

And this fits beautifully with what we know from sleep deprivation.

You are much more impulsive.

You are much more reward seeking.

You are much greater in terms of your sensation seeking.

and your addiction potential when you are not getting sufficient sleep is significantly higher.

And sure enough, when we looked in the brain, many of these dopamine-related circuits that you've described before were overactive when you were under-slapped.

And so I bring this back because it relates to your seesaw sort of analogy.