Never go to bed angry

True or false?

Most people have heard the old saying about going to bed upset: Never do it, the saying goes, or the hard feelings will fester and resentment will build.

Some say it goes back to the Bible. Regardless of its origins, the adage has been scarcely researched. But in a recent study in The Journal of Neuroscience, scientists found there might be a nugget of truth to it: Going to sleep after experiencing negative emotions appears to reinforce  them.

In the study, scientists recruited 106 men and women and exposed them to images that elicited various emotions. In some cases the emotions were negative  —  for instance, after seeing an unsettling image of an accident or traumatic scene. In other cases, the images produced positive or neutral emotions.

The researchers then looked at what happened when the subjects were shown both new images and the previous ones 12 hours later — either in the morning after a night of sleep, or at the end of a full day of wakefulness. They also measured brain activity during the rapid eye movement, or REM, phase of sleep, when dreams occur.

The scientists found that staying awake blunted the emotional response to seeing the upsetting images again. But when the subjects were shown the disturbing images after a night of sleep, their response was just as strong as when they had first seen them —  suggesting that sleep “protected” the emotional response.

Other studies have found that sleep, perhaps as an evolutionary mechanism, enhances emotional memories. The authors pointed out that after an unsettling experience, many people have trouble sleeping — perhaps the brain’s way of trying to keep the memory or emotions from being stored.

The verdict
Going to sleep upset or disturbed preserves the emotion, research suggests.