HMN 2025: What is the The secret power of sleep: blocking unwanted memories

The link between poor sleep and mental health problems may be linked to deficits in brain regions that prevent unwanted thoughts from thinking, according to a study from the University of East Anglia (UEA).

Sleep problems play an important role in the onset and maintenance of many mental health problems, but the reason for this link is elusive.

A new study, published In Proceedings of the National Academy of Sciencesoffers new insight into the cognitive and neural mechanisms underlying the link between sleep and mental health. These findings could support the development of new treatments and prevention strategies for mental health problems such as depression and anxiety.

Dr Marcus Harrington, Senior Lecturer in the School of Psychology at UEA, is lead author of the paper ‘Memory control deficits in the sleep-deprived human brain’. He worked with colleagues from the universities of York, Cambridge, Sussex and Queen’s (Canada).

Functional neuroimaging was used to reveal for the first time that deficits in memory control after sleep deprivation are linked to difficulties in engaging brain regions that support inhibition of memory retrieval, and that nocturnal rejuvenation of these brain regions is associated with rapid eye movements. paradoxical sleep.

Dr Harrington said: “Memories of unpleasant experiences can intrude into consciousness, often in response to reminders.

“While these intrusive memories are an occasional, momentary disruption for most people, they can be recurring, vivid, and upsetting for people with mental health disorders such as depression, anxiety, and post-stress disorder. traumatic.

“Since memories play a central role in our affective perception of the outside world, failures of memory control may go a long way toward explaining the relationship between sleep loss and emotional dysregulation.

“A better understanding of the mechanisms that precipitate the emergence of intrusive memories is essential to improve emotional well-being and reduce the global burden of mental illness.”

Eighty-five healthy adults attempted to suppress unwanted memories while images of their brains were taken using functional MRI. Half of the participants enjoyed a restful night’s sleep in the sleep laboratory before the task, while the other half stayed awake throughout the night.

During memory suppression, well-rested participants showed greater activation of the right dorsolateral prefrontal cortex, a brain region that controls thoughts, actions, and emotions, compared to those who stayed awake all night . Rested participants also showed reduced activity in the hippocampus, a brain region involved in memory retrieval, during attempts to suppress unwanted memories.

Among participants who slept in the lab, those who spent more time in REM sleep were better able to engage the right dorsolateral prefrontal cortex during memory suppression, highlighting the role of REM sleep in restoring memory. prefrontal control mechanisms that underlie the ability to prevent unwanted memories. to enter into conscious thought.

Dr Harrington said: “Taken together, our findings highlight the essential role of sleep in maintaining control over our memories and ongoing thoughts. »