Biofeedback?

In my rough drafts that are a few days old, I find it fairly easy to see where the "live spots" are and what parts are just filler and can go.

Yet I don't recognize while I'm writing the moments when I'm producing the good stuff. (Usually, it's not the times I might guess.)

So, it occurred to me while I was driving in this morning that the state of "doing-the-good-stuff" might be trackable with a technology like biofeedback. I'd be interested in knowing what the bodily state is at those moments, so that I could learn to reproduce them. Is this possible? Does anyone know?

I have learned a couple of things about the likeliest mental/emotional state. It's intent but relaxed focus (hypnotic trance), and lack of self-awareness. That second part is hard to set out to create.

What happens at such times I imagine as an inner door sliding open onto a place that's dark and mysterious, curiously both empty and teeming. Kalifornia K talks about that in one of her comments to "Writing from the Ditch." It would be nice to know how to open that door at will. I'd like to know when it's open without it getting shy and closing right up.