For me it's like #2. I also get nauseous. That's usually my first sign. I also look down and can't make eye contact. And I usually stop talking. I can hear her talking but it's like she's far away from me. And I can respond. The worst I've had it (not in therapy), I couldn't do or say anything. I was completely aware of everything, but I was literally frozen.
And yes, L labels it as dissociation. She says there are stages and can be different for different people.