Researchers have suggested that the human brain prioritises our most important memories during sleep.

A new study has revealed that we view things we care about the most as priorities when it comes to retaining information and creating memories. Previous studies have confirmed that we use downtime to consolidate the day’s events, but this is the first study to investigate the impact of how much we care about certain things.

Researchers from Swansea University presented their findings at the British Science Festival last week. During their research, the team presented a group of 80 non-Welsh speakers with a tablet, which used an app to translate English words into Breton and Welsh words. Participants were then asked to recall the words 12 hours later, some after a period of sleep and some after no sleep. Participants were asked to rate the value of the Welsh language to them and this was recorded.

Researchers found that those who slept before recalling the words were more likely to remember more words. They also discovered that participants who slept and placed greater importance on the Welsh language, performed better.

Professor Mark Blagrove, co-author of the study, explained that the more importance you place on something, the more likely you are to remember it. The brain retains experiences, but it seems that it works harder to remember those that mean something to us.

Participants underwent tests in a sleep laboratory at Swansea University. The findings are set to be published in the Journal of Sleep Research in the weeks to come.