Dr. Matt Walker

I don't want to be social.

I don't want to learn.

I don't want to exert effort.

I don't want to exercise.

I just don't want to do much of anything.

However, when you provoke me and you force me to interact or there is a very strong emotional event that I experience, I go all the way over into the strongly sympathetic.

So it's almost as though...

We had the prediction that there was going to be a very tight hinge and the screw was tightening the more sympathetic you became.

It was much more that you were in this sort of parasympathetic state, this sort of non-motivational state.

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.