Well, it's essentially a combination of this:
After spending 15 minutes deprived of sight and sound, each person completed a test called the “Psychotomimetic States Inventory,” which measures psychosis-like experiences and was originally developed to study recreational drug users.
Among the nine participants who scored high on the first survey, five reported having hallucinations of faces during the sensory deprivation, and six reported seeing other objects or shapes that weren’t there. Four also noted an unusually heightened sense of smell, and two sensed an “evil presence” in the room. Almost all reported that they had “experienced something very special or important” during the experiment.
As expected, volunteers who were less prone to hallucinations experienced fewer perceptual distortions, but they still reported a variety of delusions and hallucinations.
The researchers were not altogether surprised by such dramatic results from only 15 minutes of sensory deprivation. Although few scientists are studying sensory deprivation today, a small body of research from the 1950s and 1960s supports the idea that a lack of sensory input can lead to symptoms of psychosis.
“Sensory deprivation is a naturalistic analogue to drugs like ketamine and cannabis for acting as a psychosis-inducing context,” Mason wrote, “particularly for those prone to psychosis.”
Ten rats were subjected to total sleep deprivation (TSD) by the disk apparatus. All TSD rats died or were sacrificed when death seemed imminent within 11-32 days. No anatomical cause of death was identified. All TSD rats showed a debilitated appearance, lesions on their tails and paws, and weight loss in spite of increased food intake. Their yoked control (TSC) rats remained healthy. Since dehydration was ruled out and several measures indicated accelerated use rather than failure to absorb nutrients, the food-weight changes in TSD rats were attributed to increased energy expenditure (EE). The measurement of EE, based upon caloric value of food, weight, and wastes, indicated that all TSD rats increased EE, with mean levels reaching more than twice baseline values.
Edited by Zan, 27 August 2011 - 03:36 AM.