Summary: A new study from the University of East Anglia reveals how sleep deprivation makes it harder for people to control unwanted memories. Sleep-deprived participants had difficulty activating the part of the brain responsible for memory control, leading to an inability to suppress intrusive memories over time. The research, published in Proceedings of the National Academy of Sciences, suggests that sleep, particularly REM sleep, plays a critical role in memory regulation and emotional well-being. These findings may help inform new treatments for mental health disorders such as depression, anxiety, and PTSD, which are often linked to poor sleep.
Key Takeaways:
- Sleep and Memory Control: Sleep deprivation impairs the brain’s ability to suppress unwanted memories, highlighting the role sleep plays in memory regulation.
- Role of REM Sleep: Researchers found thatREM sleep is essential for restoring brain regions involved in memory control, which helps prevent intrusive memories from affecting mental health.
- Mental Health Implications: The study provides new insights into how sleep loss contributes to emotional dysregulation, offering potential avenues for treating sleep-related mental health conditions like depression and PTSD.
The link between poor sleep and mental health problems could be related to deficits in brain regions that keep unwanted thoughts out of mind, according to research from the University of East Anglia.
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 Sciences, offers fresh insight into the cognitive and neural mechanisms underlying the connection between sleep and mental health. Researchers say these findings could support the development of novel treatments and prevention strategies for mental health problems such as depression and anxiety.
Marcus Harrington, PhD, a lecturer in the University of East Anglia’s School of Psychology, is the lead author of the paper. He worked with colleagues at the universities of York, Cambridge, Sussex, and Queen’s University (Canada).
Sleep Deprivation Disrupts Memory Control
Functional neuroimaging was used to reveal that deficits in memory control after sleep deprivation are related to difficulties in engaging brain regions that support the inhibition of memory retrieval and that the overnight rejuvenation of these brain regions is associated with rapid eye movement (REM) sleep.
“Memories of unpleasant experiences can intrude into conscious awareness, often in response to reminders,” says Harrington in a release. “While such intrusive memories are an occasional and momentary disturbance for most people, they can be recurrent, vivid, and upsetting for individuals suffering from mental health disorders such as depression, anxiety, and post-traumatic stress disorder.
“Given that memories play a central role in our affective perception of the external world, memory control failures may go a long way towards explaining the relationship between sleep loss and emotional dysregulation. A better understanding of the mechanisms that precipitate the occurrence of intrusive memories is vital to improving emotional wellbeing and reducing the global burden of mental illness.”
Study Methodology and Results
Eighty-five healthy adults attempted to suppress unwanted memories while images of their brain were taken using functional MRI. Half of the participants enjoyed a restful night of sleep in the sleep lab before the task, whereas the other half stayed awake all night.
During memory suppression, the well-rested participants showed more activation in the right dorsolateral prefrontal cortex—a brain region that controls thoughts, actions, and emotions—compared to those who stayed awake all night. The rested participants also showed reduced activity in the hippocampus—a brain region involved in memory retrieval—during attempts to suppress unwanted memories.
Among the 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, pointing to a role for REM sleep in restoring prefrontal control mechanisms underpinning the ability to prevent unwanted memories from entering conscious thought.
Relative to sleep-rested participants, sleep-deprived participants were unable to properly engage the right dorsolateral prefrontal cortex during memory suppression, leading to a behavioral deficit in the ability to downregulate unwanted memories over time.
“Taken together, our findings highlight the critical role of sleep in maintaining control over both our memories and ongoing thoughts,” Harrington says in a release.
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