A recent study published in the Proceedings of the National Academy of Sciences (PNAS) explores a promising new approach to alleviating mental health issues by weakening negative memories through the reactivation of positive ones. Conducted by an international team of researchers, the experiment involved 37 participants who were asked to associate random words with negative images. The researchers then attempted to reprogram half of these associations to 'intervene' in the negative memories.
The findings indicate that this procedure not only reduces the recall of unpleasant memories but also increases the involuntary retrieval of positive memories. The team utilized established databases of images classified as negative (e.g., injuries or dangerous animals) versus positive (e.g., serene landscapes and smiling children).
On the first night, memory training exercises were employed to help volunteers connect negative images with nonsensical words created for the study. The following day, after sleep consolidation, the researchers attempted to link half of the words with positive images in the participants' minds.
During the second night of sleep, recordings of the nonsensical words were played during non-rapid eye movement (NREM) sleep, a phase known to be crucial for memory retention. Brain activity was monitored using electroencephalography.
The results showed that theta-band activity in the brain, associated with emotional memory processing, increased in response to memory audio signals and was significantly higher when positive signals were used. Follow-up questionnaires indicated that volunteers were less able to recall negative memories mixed with positive ones, and positive memories surfaced more frequently than negative ones, perceived with a more favorable emotional bias.
The non-invasive intervention during sleep holds potential for altering negative recall and emotional reactions, according to the researchers. They suggest that these findings may offer new approaches for treating pathological or traumatic memories.
It is important to note that the study was conducted in a strictly controlled laboratory context, ensuring the accuracy of the results but not fully reflecting the complexities of real life and the ways memories are formed. For instance, the unpleasant images used in the experiment may not replicate the impact of a real traumatic event, which would be significantly harder to rewrite.
Evidence suggests that the brain replays memories during sleep, a key aspect for research on enhancing or erasing them. However, due to numerous variables—such as types of memories, brain regions, and sleep phases—further time will be needed to fully understand the mechanisms of memory editing and the durability of effects.
The process of replacing negative memories with positive ones appears promising, but more research is required to determine its effectiveness. The authors of the study see opportunities for developing methods to weaken traumatic and unpleasant memories.