I have a younger sister who 'zones out' sometimes. It doesn't happen too often (I think), and when it does she usually just stares off into space and acts oblivious to her surroundings. Sometimes, though, she goes NUTS (screaming, maniacal laughing, chasing me)!
I try to snap her out of it, but nothing works. You have to wait for her to calm down. And then when she does, she claims to not remember anything that happened while she 'zoned out'. For example, just the other day my sister had a friend over and she 'zoned out'. She was spinning in circles, staring off into space, and saying something about a windmill. then she chased her friend and me down the hall. We were trying to snap her out of it (her friend shook her and gave her face a few slaps), but nothing worked. Suddenly she just stopped; she was like "Huh?" and then she was fine!
Later when I asked my sister about it, she said that she didn't remember zoning out or chasing her friend and I, and that it never happened. Do you think this is just my little sister's way of getting attention (she does get a lot of attention, by the way), or do you think that something may be wrong? Like i said, this 'zoning out' thing doesn't happen too much, but when it does it can be a little scary.