‘A good laugh and a long sleep are the best cures in the doctor’s book.’ This thoughtful Irish proverb seems to be particularly relevant for the following discovery. According to this study by the University of Massachusetts Amherst, sleep not only sharpens memory, but also facilitates and enhances complex cognitive skills.
In this investigation, a total of two studies were conducted for highlighting the possible benefits of sleep. During the first study, the effects of sleep were examined on affect-guided decision-making that is decisions on meaningful topics. It included a group of 54 young adults who were taught to play a card game. Here subjects had to play the game and win or lose the play money. Those with a normal night’s sleep as part of the study apparently drew from decks that gave them the greatest winnings four times more often than those who spent the 12-hour break awake. Also they may have understood the underlying rules of the game in a much better way than their peers.
“This provides support for what Mom and Dad have always advised. 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,” added Rebecca Spencer.
The next study encompassed two groups of 18- to 23-year-old college undergraduates. The participants received a brief morning or afternoon preview of the Iowa Gambling Task. This is a gambling card game that supposedly tracks frontal lobe function, where more emotional decisions originate. After explaining the task, subjects had to come back within 12 hours. While 28 subjects who got the preview in the afternoon went home to a normal evening and their usual night of sleep, the other 26 who received the game preview in the morning, came back after a day of normal activities with no naps.
In the second visit, scientists played the full gambling task for long enough to learn that drawing cards from four decks of cards yielded different rewards of play money. The ultimate goal was to avoid losing and collect as much play money as possible. Subjects were allowed to sleep between the game’s brief introduction and the longer play session showed both superior behavioral outcomes. For assuring that time of day didn’t explain the different performance between sleep and wake groups, experts 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 sleep patterns and the groups didn’t differ on overall game skills at the start. Equal number of males and females were included in each group. On completion of both the studies, it was suggested that sleep boosts several cognitive skills and memory.
The study is published in the online issue of the Journal of Sleep Research.