User:Cplatmaster/microsleep article editing

A microsleep is an episode of sleep which may last for a fraction of a second or up to thirty seconds. Often, it is the result of sleep deprivation, mental fatigue, depression, sleep apnea, hypoxia, narcolepsy, or hypersomnia. Microsleeping can occur at any time, typically without significant warning.

Microsleeps (or microsleep episodes) become extremely dangerous when occurring during situations which demand constant alertness, such as driving a motor vehicle or working with heavy machinery. People who experience microsleeps usually remain unaware of them, instead believing themselves to have been awake the whole time, or to have temporarily lost focus.

Occurrence
Microsleeps are most likely to occur at the times of day when the body is "programmed to sleep", mainly during pre-dawn hours and mid-afternoon hours. The chances of microsleep occurrence are cumulative, meaning the less someone has made a point to sleep regularly and for a significant amount of time, the greater their chances of microsleeping.

Dangers
After a microsleep episode while driving a car, drivers may suddenly realize several seconds have passed by unnoticed. It may not be obvious to drivers that they were asleep, although this is in fact what happened. The sleeping driver is at very high risk for having an accident during a microsleep episode.

Many accidents and catastrophes have resulted from microsleep episodes in these circumstances. For example, a microsleep episode is claimed to have been one factor contributing to the Waterfall train disaster in 2003; the driver had a heart attack and the guard who should have reacted to the train's increasing speed is said by his defender to have microslept, thus causing him to be held unaccountable.

Identifying factors
There is little agreement on how best to identify microsleep episodes. Some experts define microsleep according to behavioral criteria (head nods, drooping eyelids, etc.), while others rely on EEG markers. One study at the University of Iowa defined EEG-monitored microsleeps in driving simulation as "a 3–14 second episode during which 4–7 Hz (theta) activity replaced the waking 8–13 Hz (alpha) background rhythm."