Yes... its the sleep paralysis... i have it sometimes, speacially when im sleeping more than my body needs (i love to sleep)... and really its very scary... mainly when you feel like a "presence" near you... i never heard any laughters, only "felt" that there was "something" in my room... something that scared me... and i coulndt move... i only could wish to awake... then, when i awoke i was shivering, so scared i went... then, awake, i realized that there was nothing (visible) in the room... weird...