It has been long established that during sleep, the brain works on consolidating a person's memories. But a recent study has found that the brain, during sleep, actually prioritizes the memories and experiences that people care about most.

A study discussed at the British Science Festival suggests that during sleep, memories and experiences that are perceived as important get preferential treatment. The conclusion was made after researchers - Professor Mark Blagrove of Swansea University and Ms. Elaine van Rijn - gathered data through an experiment.

Eighty native English-speaking university students were selected to participate in the study. The students recently arrived in Wales and had not lived in the country before. They were taught several Welsh words before entering either a period of wake or sleep.

The participants were presented with 28 Welsh and Breton translations of English words. An app, installed in a tablet computer, was used to test the participants' immediate memory of the words and how many they could remember after 12 hours, either with no sleep or with only 6 hours of sleep. They were also asked to rate how much they valued the Welsh language.

The result of the study revealed that for the sleep group, the correlation between the number of Welsh words recalled and the value placed on the language was significant. According to Blagrove and Van Rijin, the data suggests that any experience that is valued personally is more likely to be consolidated by the brain during sleep.

Blagrove also said that "The mere fact that your beliefs about something seem to affect how the brain processes things during the night is really quite astounding,"

BBC News reported that the study would soon be published in the Journal of Sleep Research.