That's a good interview. I heard about the polyvagal theory somewhere else, recently, but only saw the headline and a precis. Reading the article, the theory makes sense to me.
I want to insert a little of my personal experience, with a very big caveat that the article is talking largely about sexual assault and I'm talking about something self-inflicted, and, I imagine, much less traumatic.
I used to be a big marijuana smoker, 14-20. At 16, I had a very bad shroom trip (ego-death, violent imagery, certainty about being in hell etc).
I really liked weed before that. It was like being in a cozy, intimate room with friends. My experience of smoking with people then was: the
space changed, people were more themselves, their real selves, and it was easy to communicate and share. It was really fun, and funny. I treasure those moments a lot.
After the trip, I still had a little of that. But it was like the weed 'space' had in it a kind of whirlpool at the center. I was always kind of aware of it, in the way you're aware of something in your peripheral vision. I was feeling the waves or ripple-effects of the center all the time. Sometimes, it would draw me close to it, and I've have to go to bed.
As I got older, it got more intense. I've stopped now, because three or four times something like this would happen: I'd be very relaxed, settling into the 'intimate space' and suddenly one element would seem 'off'. This could be a character in a movie we were watching, or someone's gesture, or whatever you like. Suddenly, I would be fixated on this thing with a growing sense of...something. Then I would start to have flashes of random images (the time I most remember involved 1. a basement with exposed pipes 2. paper popsicle wrappers with melted popsicle juices. ) and these would flash back and forth, growing in intensity, until some feeling/image reached a distilled peak of [This cannot happen! If that were true, it would be too horrible!] and then I'd have to lay down. I'd be totally still and silent, immovable, and over me would continue slightly softer images and ideas, and there was always comfort in hearing people talk to each other about stuff, without hearing what they were saying, just the sound of voices talking to one another, that you can vaguely locate in the space you're in. Like parents relaxing or making preparations for a party , or something while you're very sick. These states would last for hours with me unable to talk, except in a kind of free-associative babbling, until I fell asleep. Then I'd talk to everyone in the morning (What happened man? you were really fucked up!)
Like I said, I don't want to equate this to the events the author was describing, but maybe it's drawing on some similar thing? I very much felt like I 'got' his description of 'freezing' while stuff happened around you.