Justin Bieber -- Catches Some TMZzzzzz's During Depo

Justin Bieber was aggressively contentious during his 4 1/2 hour deposition Friday, but the videotape shows there were what seemed to be blackout periods as well.

We can't say for sure Justin nodded off during the depo, but it sure looks that way. His eyes closed and he seemed to be in a far away place.

People in his camp insist Bieber was not sleeping, but he does seem worn out during much of the questioning.