asleep. It is an accepted fact that true sleep deprivation (that is, you are in a situation in which no sleep is allowed to happen19) always leads to sleep or sleep intrusion (uncontrollable periods of sleep) and performance decline. In other words, if you are sleep deprived, you and everyone else know it! If, however, you think you are sleep deprived but you show no tendency to nod off when you are stretched out on a couch, does it really make sense to you, knowing what you know, that you really are sleep deprived?
