5. Sleep State Misperception
In a condition called paradoxical insomnia, some people lose the ability to differentiate between wakefulness and sleep. These individuals will often swear that they have gone days – or even weeks or months – without any sleep at all. This is not physiologically possible and objective observation demonstrates that these individuals do, in fact, sleep.
This is sometimes called sleep state misperception. It likely more often occurs when light sleep is obtained. Stage 1 sleep, the lightest of the recognized sleep stages, is characterized by light dozing. It may be so light that it is mistaken for wakefulness. In fact, studies shows that when people are observed to be in stage 1 sleep on an electroencephalogram (EEG), half of those who are awakened will say that they were not asleep while the other half will say that they were. This transition state of consciousness may contribute to this misperception of sleep.