In his book The Doors of Perception, author and psychonaut Aldous Huxley presents the idea of the mental reducing valve in order to explain the significance of the psychedelic experience. According to Huxley, the central nervous system's main function is to shut out the majority of what we perceive;[10] the brain filters those perceptions which are useful for survival. Society aids in this filtering by creating a symbolic system which structures our reality and which reduces our awareness.
Psychedelic experiencing has the effect of reducing the strength of the mind's reducing valve, which allows for a broader spectrum of one's overall experience to enter into conscious experience. A person undergoing a psychedelic trip temporarily possesses a higher level of conscious awareness.