selective sleep deprivation

Selective sleep deprivation involves preventing specific stages of sleep to study their functions. Researchers either keep subjects awake entirely (total deprivation) or allow limited sleep (partial deprivation). In selective deprivation, subjects are allowed natural sleep until the target stage is reached, then prevented from entering it. This method helps scientists understand the physiological and behavioral roles of particular sleep stages by observing what happens in their absence.

Studies have shown that sleep deprivation can lead to deteriorated physiological functioning, and in animals, long-term deprivation can be fatal. In humans, effects can include irritability, memory lapses, confusion, fatigue, and difficulty concentrating. While brief hallucinations and bizarre behavior have been observed after extended deprivation, these symptoms usually resolve with subsequent sleep. Some research suggests sleep deprivation may increase the risk of obesity and diabetes. Selective deprivation of REM sleep, in particular, has been linked to mood regulation and may even be helpful in treating depression.12