Between the crazy reality of our busy human world and the land of dreams, we pass a portal of two states called Hypnagogic and Hypnopompic hallucinations / images / or states. These are the conditions taking place between wakefulness and sleep. Many psychologists and philosophers throughout the 19th century used hypnagogia as a source of creativity. Early references to hypnagogia are to be found even in the writings of Aristotle.

The term Hypnagogia inclues both states: Hypnagogic defines the period when a person falls asleep. 

Hypnopompic describes the period when a person wakes up. Hypnagogia is marked by a high level of both alpha and theta brainwaves.