A study investigated the effects of going to bed 2 hours later than normal but getting up at the usual time. It found that people not only became more impulsive and prone to mistakes the following day but also experienced a flattening of normally pleasurable feelings.
Missing out on a good night’s sleep is a well-known cause of cognitive and emotional problems and making people more accident-prone the next day.
Over longer periods, sleep deprivation is associated with worse mental and physical health.
Most research into the cognitive and emotional effects of sleep deprivation involves volunteers spending several nights in the unfamiliar surroundings of a sleep laboratory.
Psychologists wanted to investigate the effects under more natural circumstances, while people were at home and sleeping in their own beds.
They discovered that less sleep led the participants to feel worse the next day, but not in the sense of feeling down or depressed. Rather, they experienced fewer positive emotions.
The study tracked 52 healthy adults aged between 18 and 35 years over a period of 11 days.
To monitor sleep, the researchers asked the volunteers to wear motion sensors on their wrists and fill out a “sleep diary” every morning. The diary included questions about what time the person went to bed and got up, how long it took them to fall asleep, and any periods of wakefulness during the night.
After maintaining their normal sleep habits for 7 days, the participants went to bed 2 hours later than usual for the last 3 nights of the study but got up at their regular time.
“In the imposed sleep deprivation phase, participants crawled under their covers 2 hours later than they normally did and had to get up at their usual time” .