i tend to lose myself to the drums, i just concentrate on them, i know exactly what i should be playing, and if a guitarist messes up keep going, the drummer won't wait for them to catch up! I tend to get to the point where i sort of drift off elsewhere if i really know what i'm doing and before i know it, the gig is over! It's kind of disappointing!
Oh yeah, i tend to take notice of the vocals too, just so i know where in the song we are!