The brain is like a human computer that tends to capture and store all memories of our life, including the ones we want to be forgotten. While it may seem as though it’s impossible to forget painful memories, a team of scientists has come up with an interesting discovery to help: sound cues.

Researchers at the University of York say playing sounds while people are asleep is a simple technique to help people forget certain memories. More specifically, they found evidence of a tendency to forget when a common sound cue is made during slow wave sleep (SWS). 

While this interesting discovery is still somewhat in its early phase, the study authors shed light on the fact that it paves way for the growth of new strategies to help lessen both traumatic and intrusive memories alike. Beyond that, prior studies have shown some evidence that playing the same sound cues during sleep can help retain and strengthen memory. Meanwhile, this is the first research to bring forth strong evidence that this same technique could as well help people forget.

In this study, the researchers involved a total of 29 participants. Of the 29, 17 of them were males and the other 12 were females. The researchers assessed the sleep quality of the participants over the past month before the start of the study. Participants were verified to have no difficulty falling asleep. Then, they taught the participants, through headphones, the association between two-word pairs. For instance, they were instructed to learn both word pairs: “David Beckham – Bicycle” and “Office – Bicycle”. 

The researchers then allowed the participants to sleep overnight for about 8 hours in the laboratory’s bedroom while they monitor their brain activity. As soon as the participants were found to have crossed into sleep stage 3 (also called slow wave sleep), the researchers started to recite the ‘object’ quietly through a mounted speaker (i.e. Bicycle). The object was the common overlapping item that allowed the scientists to detect a difference in participants’ memory between the first and second pair of words. 

Prior research found that mastering a pair of words along with playing a sound associated with the pair while asleep helped boost participants’ memory for both words when they woke up the following day. In this case, however, the researchers found that the overlapping word pairs resulted in reduced memory for one and an increase in memory for the other pair. This convinced researchers of the chances that repeatedly playing associated sounds can certainly cause selective forgetting when asleep.

“The relationship between sleep and memory is fascinating. We know that sleep is critical for memory processing, and our memories are typically better following a period of sleep. The exact mechanisms at play remain unclear, but during sleep, it seems that important connections are strengthened and unimportant ones are discarded,” says the senior author of the study, Dr. Aidan Horner from the Department of Psychology at the University of York.

In conclusion, the study authors aim to conduct more research on exactly how cues cause forgetting to be able to switch the effect on and off. More so, to see if the same technique can be applied to weaken current real-world memories.

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