'Sleep on it' is excellent, science-based advice, study finds

May 25, 2011, University of Massachusetts Amherst

(Medical Xpress) -- In recent years, much sleep research has focused on memory, but now results of a new study by University of Massachusetts Amherst psychologist Rebecca Spencer and colleagues suggest another key effect of sleep is facilitating and enhancing complex cognitive skills such as decision-making.

In one of the first studies of its kind, Spencer and postdoctoral fellow Edward Pace-Schott investigated the effects of sleep on affect-guided decision-making, that is decisions on meaningful topics where subjects care about the outcome, in a group of 54 . They were taught to play a card game for rewards of play money in which wins and losses for various card decks mimic casino gambling.

Subjects who had a normal night’s sleep as part of the study drew from decks that gave them the greatest winnings four times more often than those who spent the 12-hour break awake, and they better understood the underlying rules of the game. believe rule discovery is an often hidden yet key factor that is crucial to making sound decisions.

"This provides support for what Mom and Dad have always advised," says Spencer. "There is something to be gained from taking a night to sleep on it when you’re facing an important decision. We found that the fact that you slept makes your decisions better."

This role of sleep in everyday life is accepted as common wisdom, but it hasn’t been well characterized by science until now, she adds. She and her colleagues believe this sleep benefit in making decisions may be due to changes in underlying emotional or cognitive processes. "Our guess is that this enhanced effect on decision-making is something that depends on rapid-eye-movement or REM sleep, which is the creative period of our sleep cycle," the psychologist notes. Results are in the current early online issue of the Journal of Sleep Research.

The UMass Amherst study used the Iowa Gambling Task, a gambling card game that assesses frontal lobe function, where more emotional decisions originate. Spencer explains, "It means that you care about the wins and losses. You care about winning."

To begin, the researchers gave two groups of 18- to 23-year-old college undergraduates a brief morning or afternoon preview of the gambling task, so brief that it was not possible for them to learn its underlying rule. Subjects were then asked to come back in 12 hours. The 28 subjects who got the preview in the afternoon went home to a normal evening and their usual night of sleep while the 26 who received the game preview in the morning came back after a day of normal activities with no naps.

On the second visit, subjects played the full gambling task for long enough to learn that drawing cards from four decks of cards yielded different rewards of play money: Drawing from two advantageous decks yielded low rewards, occasional low losses and a net gain over many draws, while drawing from disadvantageous decks yielded high rewards, occasional high and a net loss over many draws. The object was to avoid losing and collect as much play money as possible.

Subjects who got to sleep between the game’s brief introduction and the longer play session showed both superior behavioral outcome, that is, more advantageous draws, and superior rule understanding when asked to explain them at the end, than those who did not sleep between sessions.

To assure that time of day didn’t explain the different performance between sleep and wake groups, the researchers added two smaller groups of 17 and 21 subjects to perform both the preview and the full task either in the morning or the evening. All subjects said they had normal patterns (for college students) and the groups didn’t differ on overall game skills at the start. Males and females do not differ in game-playing skills, the authors point out, but there were equal numbers in each group.

Related Stories

Recommended for you

Modulating molecules: Study shows oxytocin helps the brain to modulate social signals

January 17, 2018
Between sights, sounds, smells and other senses, the brain is flooded with stimuli on a moment-to-moment basis. How can it sort through the flood of information to decide what is important and what can be relegated to the ...

Reducing sessions of trauma-focused psychotherapy does not affect effectiveness

January 17, 2018
Posttraumatic Stress Disorder (PTSD) patients treated with as few as five sessions of trauma-focused psychotherapy find it equally effective as receiving 12 sessions.

How past intentions influence generosity toward the future

January 17, 2018
Over time, it really is the thought that counts – provided we know what that thought was, suggests new research from Duke University's Fuqua School of Business.

Baby brains help infants figure it out before they try it out

January 17, 2018
Babies often amaze their parents when they seemingly learn new skills overnight—how to walk, for example. But their brains were probably prepping for those tasks long before their first steps occurred, according to researchers.

Tracking the impact of early abuse and neglect

January 17, 2018
Children who experience abuse and neglect early in life are more likely to have problems in social relationships and underachieve academically as adults.

Study: No evidence to support link between violent video games and behaviour

January 16, 2018
Researchers at the University of York have found no evidence to support the theory that video games make players more violent.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Noumenal
1 / 5 (1) May 25, 2011
sigh, next they'll do a study that finds red is actually red. Wonderful.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.