A while back I had an odd experience with meditating (something I don't do that often). I started out sitting on my bed with my eyes closed, but at some point opened my eyes. Eventually it was like my consciousness started to recede. Things like reflection and inner narrative weakened or turned off, while my vision continued more or less normally. I felt like I couldn't move my hands anymore. I also started laughing continuously for several minutes. Eventually I "woke up" again. It felt kind of like (part of?) my consciousness had fallen asleep while the rest of my brain stayed awake.

Is this a normal kind of thing to happen while meditating? It was a bit disturbing but overall a positive experience I think.