Slipping into slumber while holding on to a freshly formed bad memory engraves it in the brain, making it harder to shake off later, a team from China and the US reported in the journal Nature Communications. “This study suggests that there is certain merit in this age-old advice: ‘Do not go to bed angry,’” said study coauthor Liu Yunzhe, who conducted the research at Beijing Normal University. “We would suggest to first resolve [the] argument before [going to] bed.” Liu and the research team used 73 male college students to test the impact of sleep on memory. The participants were trained over two days to associate specific images with negative memories.
Later, they were made to look at the pictures again and instructed either to recall the negative associations or to fight against it and not let the memory enter their mind. The test was done twice — once after the participants had had a night of sleep and once only half an hour after a training session. All the while, scientists scanned the participants’ brain activity. Participants found it much harder to suppress memories after sleep, the team found, and the scans revealed the souvenirs were likely being stored in a part of the brain with longer-term memory connections.
Sleeping is known to affect how newly acquired information is stored and processed in the brain, moving from short to longer-term networks. Memories of negative or traumatic events often last longer than those of positive or neutral experiences, the research team said, but they can, to an extent, be consciously controlled. An inability to suppress bad memories has been linked to a number of psychiatric problems, including depression and post traumatic stress disorder.
Before this latest study, “we did not know whether it is better or worse to suppress memories before or after sleep,” Liu said. Better understanding of such processes could boost the treatment of psychiatric problems. “For example, sleep deprivation immediately after traumatic experiences may prevent traumatic memories from being consolidated ... and thus provide the opportunity to block the formation of traumatic memories,” the study authors wrote.
Do not sleep on it: going to sleep angry makes things worse - Taipei Times