dual-input model of hallucinations

   A term used to denote a hypothetical model for the mediation of hallucinations that was formulated during the 1960s by the American psychiatrist Louis Jolyon West (1924-1999). Basically, the dual-input model would seem to constitute a variant of the older " perceptual release model. In 1962 West used the metaphor of a man standing at a closed glass window opposite a fireplace, looking out of the window into the garden while the Sun is setting, watching the garden becoming gradually darker, and the reflection of the fireplace becoming gradually brighter. In West's own words, "In perceptual release, the daylight (sensory input) is reduced while the interior illumination (general level ofarousal) remains bright, and images originating within the rooms of our brains may be perceived as though they came from outside the window of our senses. The theory thus holds that a sustained level and variety ofsensory input normally is required to inhibit the emergence of percepts or memory traces from within the brain itself." Like the "experiential projector model of hallucinations, the dual-input model emphasizes the role of arousal in the release of endogenous percepts. As West maintains, "The greater the level of arousal, the more vivid the hallucinations."

   References

   West, L.J. (1962). A general theory of hallucinations and dreams.In: Hallucinations.Edited by West, L.J. New York, NY: Grune & Stratton.