I don't know, but I sometimes have tactile hallucinations when my eyes are closed. I'll feel something on me, but when I open my eyes there's nothing there. One that recently freaked me out because it was so clear was I was lying in bed awake but with my eyes closed, and I felt my cat jump up on the bed and walk across my legs. I opened my eyes and sat up to pet her, but she was asleep on the other side of the room. That was pretty unsettling. That kind of thing only happens when I'm a little on the manic side.