Surely we have all heard the advice of “ never go to bed angry .” Now science explains why. And it is that, normally, the hours of sleep help us to process the information of the day and to store it in the memory. New research has found that negative memories are more difficult to suppress if we go to bed thinking about them or if we have just had an argument . Rather, the opposite happens: they are consolidated in our memory.
A team of neuroscientists from University College London (UK) carried out an experiment involving 73 men who were asked to look at 26 photos of people with neutral faces ; that is, the faces were not associated with either positive or negative emotions. However, in a later vision, they paired each face with a truly disturbing image: corpses, amputations, women crying uncontrollably, injured children, sad children … in order to associate each face with an unpleasant image.
Subsequently, the researchers divided the participants into two groups, showing them again some of the photos of those faces and asking them to try to forget the negative memory associated with the images . This attempt to forget the bad memory was made 30 minutes after the first viewing or after a restful sleep.
When the experiment was performed 30 minutes later , the volunteers were 9% more likely to erase the images from their brain . However, in the test the next day after sleeping through the night, the percentage dropped to 3% . They had more trouble forgetting.
These results suggest that sleep can make it harder for people to forget things they would rather not remember , the researchers say.
During the memory suppression task, participants’ brains were also scanned using MRI and brain activity compared. The 30-minute experiment activated neural circuits in the brain’s hippocampus. However, in the one done after a night’s sleep, the neuronal circuits that were activated appeared distributed throughout the cerebral cortex – not just the hippocampus – which is why it was more difficult for them to suppress the memory.
Thus, our ability to erase negative memories with sleep decreases because ur brain when we sleep, reorganizes, consolidates these memories stored and negative. The study makes it clear: never go to bed angry or you won’t be able to easily forget what happened.
The work has been published in the journal Nature Communications.
