PUBLISHED: 23:36 EST, 3 April 2012 | UPDATED: 02:43 EST, 4 April 2012
A good night’s sleep boosts our positive memories, according to a study.
Researchers split 70 young adults into two groups – one that got to sleep overnight and one that had to stay awake.
Both groups were required to look at positive images containing items such as puppies and flowers, and both at neutral images featuring furniture and dinner plates.
The participants’ memories of the images were then tested 12 hours later, after either a period of sleep or staying awake, with the positive memories stronger for the sleepers.
‘Results showed sleep enhances our emotionally positive memories,’ said Professor Rebecca Spencer of the University of Massachusetts.
‘Positive memories may even be prioritised for processing during sleep.’
Professor Spencer believes the results could also have significant implications for treating post-traumatic stress disorder, as wakefulness could have the unintended effect of degrading positive memories as well as negative memories.
Scientists already know insomnia is a healthy biological response for people to reduce negative emotions associated with a traumatic event.
But the study reinforces the idea that sleep is important to preserve all our memories.
When people are awake, our minds may cloud any negative thought, but it also distorts the positive.
The professor said: ‘The study suggests that insomnia should be treated at some point after a traumatic event – perhaps a few days/weeks depending on the level of trauma – so that these positive memories can be strengthened and eventually outweigh the negative.
‘For mildly negative memories, we can learn something from them and we should remember them. Moreover, sleep enhances memories for the positive events that we are exposed to and want to remember.’
In a separate study presented at the same Chicago conference, University of Notre Dame researchers found that test subjects are more likely to remember cartoons that are humorous than non-humorous ones.
Scientists said it underlined the idea that preserving positive memories is both useful and good for our wellbeing.