Being able to erase bad memories and traumatic flashbacks could help treat a host of mental health issues, and scientists have found a promising new approach to doing just that: 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 these associations and “interfere” with the bad ones. memories.
“We found that this procedure weakened the recall of aversive memories and also increased involuntary intrusions of positive memories,” to write the researchers in their published article.
For the study, the team used established databases of images categorized as negative or positive – think human injuries or dangerous animals, compared to calm landscapes and smiling children.
On the first evening, memory exercises were used to get volunteers to associate negative images with nonsense words invented for the study. The next day, after sleeping at consolidate these memoriesthe researchers attempted to associate half of the words with positive images in the participants’ minds.
During the second night of sleep, recordings of the absurd words spoken were broadcast, during the non-rapid eye movement (NREM) phase of sleep known to be important for memory storage. Brain activity was monitored by electroencephalography.
Theta band activity in the brain, linked to emotional memory processing, was observed in response to audio memory cues, and was significantly increased. higher when positive cues were used.
Through questionnaires the next day and several days afterward, the researchers found that the volunteers were less able to recall negative memories that had been blurred with positive memories. Positive memories were more likely to come to mind than negative words for these words, and were perceived with a more positive emotional bias.
“A non-invasive sleep intervention can thus modify aversive memories and affective responses”, to write the researchers. “Overall, our findings may offer new insights relevant to the treatment of pathological or trauma-related memories.”
This research is in its early stages, and it is worth remembering that this was a tightly controlled laboratory experiment: this is good for relying on the accuracy of the results, but it does not reflect not exactly real-world thinking and the formation of positive or negative memories.
For example, the team says that seeing aversive images during a laboratory experiment would not have the same impact on memory formation as experiencing a traumatic event. The real thing might be harder to crush.
We know that the brain stores memories by briefly replaying them during sleep, and numerous studies have already looked at how this process could be controlled to reinforce good memories or eliminate the bad.
With so many variables at play – in terms of memory types, brain areas and sleep stages – it will take some time to understand exactly how memory editing might occur and how long the effects might last. However, this process of overwriting negative memories with positive ones seems promising.
“Our results open up broad avenues for attempting to weaken aversive or traumatic memories,” to write the researchers.
The research was published in PNAS.