Sleep can help erase bad memories: ‘Therapy for our emotions’

Sleep has been shown to have a long list of physical and mental health benefits, and now a new study suggests that it can also help “erase” bad memories.

That’s according to researchers from the University of Hong Kong, who applied a procedure called “targeted memory reactivation” (TMR) to reactivate positive memories and weaken painful ones during sleep.

“Remembering painful or traumatic experiences can be deeply distressing,” the researchers wrote in the findings, which were published in the journal PNAS. “Sleep may offer an opportunity to reduce these sufferings.”

“We developed a procedure to weaken older aversive memories by reactivating newer positive memories during sleep.”

In the study, a total of 37 participants were shown 48 “nonsense words”, each paired with a different unpleasant image, before going to sleep at night.

The next evening, they were shown half the words paired with positive images from four categories: animals, babies, people, and scenes.

During the following “non-rapid eye movement” sleep, the researchers presented “auditory memory cues.”

When the participants woke up, they had less memory for the negative images and stronger memory for the positive ones.

“Our results were consistent with recent TMR research showing that episodic forgetting can be triggered by the reactivation of intrusive memories during sleep,” the researchers wrote in the study.

“Going beyond previous research on neutral memories, our results suggest that TMR preferentially reactivated recently acquired positive memories and weakened older aversive memories, thereby altering the fate of emotional experiences.”

Dr. Earnest Lee Murray, a board-certified neurologist at Jackson-Madison County General Hospital in Jackson, Tennessee, noted that TMR has been a method for treating PTSD and other aversive (bad) memories.

“This is done by combining sensory cues with therapeutic interventions and then reintroducing these cues during specific stages of sleep,” Murray, who was not involved in the study, told Fox News Digital.

This treatment has been shown to reduce the emotional impact of aversive memories, the neurologist added.

“This study not only shows a suppression or a weakening of the aversive memory, but it does so by reactivating newer positive memories while the patient is asleep,” Murray said. “This will open the door to additional research into ways to weaken traumatic or other bad memories.”

In addition to psychotherapies, drugs are sometimes used to suppress anxiety or other aversive memories, he noted.

“This research continues to show ways to treat these conditions without the use of medications, which are often fraught with negative side effects.”

Alex Dimitriu, MD, a board-certified psychiatrist in sleep medicine and founder of Menlo Park Psychiatry & Sleep Medicine in California, was also not involved in the study, but said it is “fascinating” in what it reveals about how the brain processes memories. during sleep.

“Our brain is unpacking, processing and repackaging emotions in our sleep,” he told Fox News Digital. “I had suspected this before, and I often tell my patients that sleep is like therapy for our emotions.”

Many of the doctor’s patients have reported improvements in mood and anxiety when sleep has improved.

“There’s been evidence that in REM (dream sleep) in particular, a lot of emotional processing and rehearsal happens,” Dimitriu said. “In this study, however, the interference was in non-REM sleep, indicating that emotions are also processed in other stages of sleep.”

The process of using TMR to suppress negative emotions and strengthen positive memories can have a “tremendous impact” on people with depression or trauma, the expert said.

“I’m excited to see further research in this area, which basically means we can learn and change while we’re asleep.”

Possible limitations

The study had several limitations, the researchers noted.

“First, although our experiment aims to weaken aversive memories, the emotional experiences induced by laboratory viewing of aversive/positive images may not mimic typical traumatic experiences,” they wrote.

It can also be difficult to find positive components within some very traumatic experiences, they noted.

“Future research should explore ways to introduce intrusive positive memories, such as positive autobiographical memories or therapy-related memories, to effectively weaken real-life trauma memories,” the researchers said.

“Second, the role of REM sleep in modulating emotional memories will be further investigated.”

The study received ethical approval from the Human Research Ethics Committee of the University of Hong Kong.

Funders included the Ministry of Science and Technology of China and the National Natural Science Foundation of China, along with other grants.