Dr. Mark D'Esposito

So it's a proxy for measuring someone's dopamine.

So that's one way to do it.

And that's actually how we did it in our original studies.

We actually grouped...

individuals based on whether their capacity based on this behavioral measure was high or low.

And like you said, those who work that can only hold five or six letters, if we gave them bromocriptine, which was the dopaminergic agonist, we improved their working memory.

We got them into sort of an optimal level.

But those who were already high, we actually made them – we got them worse.

And the moral of that story was that more is just not better.

We're trying to get people optimal.

And so the real question is, you know, if we want to get people optimal like you were inferring, you have to know what their dopamine is.

Where are you on this inverted –

Another way of doing it is through genetic studies.

So we don't mean all neurotransmitters have to be broken down and re-uptaked into the brain cell in order to be used again.

And there's different ways of doing it.

In some cells, it gets transported back into the brain cell.

Other places there's an enzyme that breaks it down.

Well, there's an enzyme called COMT that breaks down dopamine in the prefrontal cortex specifically.

In a large percentage of individuals that enzyme is either overactive or underactive.

Probably about 25% of individuals it's overactive and another 25% it's underactive.