User:Trevor Steele/microsleepEdit

A microsleep is an episode of sleep which can last less than one second or be minutes long. 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 microsleep usually remain unaware of it, instead believing themselves to have been awake the whole time, or to have temporarily lost focus.

Causes
Often, microsleeping is the result of sleep associated problems such as:
 * sleep deprivation


 * mental fatigue


 * depression


 * sleep apnea


 * hypoxia


 * narcolepsy


 * hypersomnia

There also appears to be a correlation between the time of day and microsleep occurrence. A person is more likely to experience microsleep during your body's natural sleeping times. These include early morning, the common mid-afternoon nap time, and late night after hours.

Symptoms
Excessive Daytime Sleepiness is a very common symptom and is not to be confused for microsleep itself. The most obvious symptom is falling asleep for extremely short periods. However, as mentioned above, a victim of microsleep will most likely be unaware of the issue. It is even possible for somebody to microsleep with their eyes open, making it impossible for an outside observer to notice the episode.

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."

Dangers
A driver experiencing microsleep will realize that several seconds pass by unnoticed while they are driving. It is not obvious to the driver that he was asleep during these missing seconds. Any sleeping driver is at very high risk for having an accident.

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.