Using sound to erase memories.
According to recent research, playing sounds to individuals as they sleep might help them forget certain memories. Researchers from the University of York made this early finding, which might eventually be refined into methods to help in reducing intrusive and traumatic memories, according to the study’s authors.
Previous research indicated that playing “sound cues” during sleeping can be used to reinforce certain memories. This latest study offers the first strong evidence that the approach may also be used to help individuals forget.
The first author of the study, Dr. Bardur Joensen, a former Ph.D. student at the Department of Psychology, University of York, said: “Although still highly experimental at this stage, the results of our study raise the possibility that we can both increase and decrease the ability to recall specific memories by playing sound cues when an individual is asleep.
“People who have experienced trauma can suffer a wide range of distressing symptoms due to their memories of those events. Though still a long way off, our discovery could potentially pave the way to new techniques for weakening those memories that could be used alongside existing therapies.”
29 individuals were taught connections between overlapping word pairs for the research. They were instructed, for instance, to memorize the word pairings “hammer – office” and “hammer – Cardi B.”
The individuals then spent the next night in the sleep lab at the University of York. When participants entered stage three sleep, generally known as deep or slow-wave sleep, the study team gently played the word denoting the object (i.e. hammer) while analyzing their brainwaves.
According to earlier studies, memorizing a pair of words and listening to a sound connected with that pair while participants slept helped them remember the phrases when they woke up the next morning. This time, they discovered an increase in memory for one pair but a reduction in memory for the other pair when the word pairs overlapped. This suggests that playing related sounds while you sleep might cause selective forgetfulness.
According to the researchers, sleep played a crucial role in the effects they observed in their study.
Senior author of the study, Dr. Aidan Horner from the Department of Psychology at the University of York, said: “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.
“This research raises the possibility that this process could be manipulated so that sleep could be used to help weaken painful memories.
“The next steps for our research team are to establish how these cues cause forgetting, so that we can turn the effect on and off, and whether we can use the same technique to weaken existing real-world memories.”
Reference: “Targeted memory reactivation during sleep can induce forgetting of overlapping memories” by Bardur Hofgaard Joensen, Marcus Harrington, Sam BerensScott Cairney, M. Gareth Gaskell and Aidan J Horner, 17 October 2022, Learning & Memory.