Microsleeps occur when a person has a significant sleep deprivation. The brain automatically shuts down, falling into a sleep state for a period that can last 10 to 60 seconds. The person mentally falls asleep no matter what activity he or she is engaged in. Microsleeps are similar to blackouts and a person experiencing them is not consciously aware that they are occurring. Great sleep deprivation mimics psychosis: distorted perceptions can lead to inappropriate emotional and behavioral responses.