Threshold consciousness is the state of falling asleep or waking up.
Physiological phenomenom that can occur in threshold consciousness including lucid dreaming, hypnagogia, hypnopompia, hypnagogic hallucinations, and sleep paralysis. Wikibooks has more about this subject: Lucid Dreaming Lucid dreaming is the conscious perception of ones state while dreaming, resulting in a much clearer (lucid) experience and usually enabling direct control over the content of the dream. ... Hypnagogia (also spelled hypnogogia) and hypnopompia are experiences a person can go through when falling asleep in the case of hypnagogia, or waking up, in the case of hypnopompia. ... Sleep paralysis is a condition characterized by paralysis of the body shortly after waking up (known as hypnopompic paralysis) or, less often, shortly before falling asleep (known as hypnagogic paralysis). ...
Consciousness is a quality of the mind generally regarded to comprise such key features as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and ones environment. ... A form constant is one of several geometric patterns which are recurringly observed by different people during hallucinatory states. ...