We all have things we’d rather forget, whether it be your ex-partner or a particularly embarrassing moment. Now, researchers have found that playing sounds to people while they sleep can be used to help you forget bad memories.
The team, from the University of York, hopes the findings could pave the way for techniques to help weaken traumatic and intrusive memories.
We all have things we’d rather forget, whether it be your ex-partner or a particularly embarrassing moment. Now, researchers have found that playing sounds to people while they sleep can be used to help you forget bad memories
How does it work?
The effect is likely to occur because of some form of competition between the overlapping memories, Dr Horner explained.
‘It might be possible to take one aspect of a previous real-world memory – for example a particular location where an event occurred – and associate that with a new event,’ he said.
‘If we could use the sound cues during sleep to selectively boost memory for this newly learned event, then this might have the effect of decreasing memory for the original event.’
For the study, the team recruited 29 participants, who learned two overlapping pairs of words – for example David Beckham and bicycle as one pair, and bicycle and castle as the second pair.
When learning both pairs they also heard the word ‘bicycle’ being played aloud.
Participants then went to sleep and when they entered slow-wave – also known as deep – sleep, they were played the word ‘bicycle’ again.
Their memory was tested when they woke up.
Comparing performance to a control condition, where the associated sounds weren’t played during sleep, memory for one pair was boosted while they appeared to forget the association of the other pair.
Dr Bardur Joensen, first author of the study, 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.’
Previous research has found that learning a pair of words, and playing a sound associated with that pair during sleep, improved participants’ memory for the word pair when they woke in the morning.
But this is the first time they have shown a decrease in memory for a word pair, suggesting it is possible to cause selective forgetting by playing associated sounds during sleep.
Senior author Dr Aiden Horner said: ‘The relationship between sleep and memory is fascinating.
The effect is likely to occur because of some form of competition between the overlapping memories, Dr Horner explained (stock image)
‘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.’
The effect is likely to occur because of some form of competition between the overlapping memories, Dr Horner explained.
‘It might be possible to take one aspect of a previous real-world memory – for example a particular location where an event occurred – and associate that with a new event,’ he said.
‘If we could use the sound cues during sleep to selectively boost memory for this newly learned event, then this might have the effect of decreasing memory for the original event.’
The findings were published in the journal Learning & Memory.
TRAINING YOUR BRAIN TO BANISH BAD MEMORIES
A 2020 study led by researchers from Dartmouth and Princeton has shown that people can intentionally forget past experiences by changing how they think about the context of those memories.
The researchers showed participants images of outdoor scenes, such as forests, mountains and beaches, as they studied two lists of random words.
The volunteers deliberately manipulated whether the participants were told to forget or remember the first list prior to studying the second list.
Right after they were told to forget, the scans showed they ‘flushed out’ the scene-related activity from their brains.
But when the participants were told to remember the studied list rather than forget it, this flushing out of scene-related thoughts didn’t occur.
The amount people flushed out scene-related thoughts predicted how many of the studied words they would later remember, which shows the process is effective at facilitating forgetting.
To forget those negative thoughts coming back to haunt you, researchers suggest trying to push out the context of the memory.
For example, if you associate a song with a break-up, listen to the song in a new environment.
Try listening to it as you exercise at the gym, or add to a playlist you listen to before a night out.
This way, your brain will associate with a positive feeling.
If a memory of a scene from a horror film haunts you, watch the same scene during the daytime.
Or watch it without sound but play a comedy clip over the top.
