The ability to erase unpleasant and traumatic memories could help treat many mental health problems, and scientists have found a promising new approach: weakening negative memories by reactivating positive ones.
In a multi-day experiment, an international team of researchers asked 37 participants to associate random words with negative images, before attempting to reprogram half of those associations and “interfere” with negative memories .
“We found that this procedure weakened recall of aversive episodes and also increased involuntary intrusions of positive memories,” the researchers write in their paper.
For the study, the team used recognized databases of images classified as negative or positive.
Treating a range of mental health problems
On the first evening, memory training exercises were used to get volunteers to associate negative images with nonsense words made up for the study. The next day, after a nap to consolidate these memories, the researchers tried to associate half of the words with positive images in the participants’ minds.
During the second night of sleep, recordings of nonsense words spoken during NREM sleep, known to be important for memory storage, were played. Brain activity was monitored using electroencephalography.
Activity in the theta band of the brain, linked to emotional memory processing, was observed as a spike in activity in response to audio memory cues and was significantly greater when positive cues were used, he writes ScienceAlert.
By means of questionnaires applied the next day and a few days later, the researchers found that the volunteers were less able to remember the negative episodes that had been mixed with the positive ones. Positive memories were more likely to come to mind than negative ones for these words and were viewed with a more positive emotional bias.
Memory training exercises
It’s still early days for this research, and it’s worth remembering that this was a tightly controlled laboratory experiment: this is good in terms of confidence in the accuracy of the results, but it doesn’t exactly reflect real-world thinking and positive or negative memory formation.
For example, the team states that viewing aversive images in a laboratory experiment would not have the same impact on memory formation as experiencing a traumatic event. The real thing might be harder to overwrite.
We know that the brain actually saves memories by briefly replaying them during sleep, and many studies have already looked at how this process could be controlled to strengthen good memories or erase bad ones.
With so many variables at play—in terms of memory types, brain areas, and sleep phases—it will take some time to understand exactly how memory editing might occur and how long-lasting the effects might be. However, this process of overwriting negative memories with positive ones seems to be quite promising.
The research was published in PNAS.
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Source: www.descopera.ro
