Sleep is critical to solidifying our memories, and sleep deprivation has long impaired learning and memory. Now, a new study shows that sleeping just half a night – as many medical professionals and military personnel often do – affects the brain’s ability to unlearn fear-related memories. This could increase your risk for conditions such as anxiety or post-traumatic stress disorder.
The study appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, published by Elsevier.
This study gives us new insights into how sleep deprivation affects brain function to disrupt the fear extinction.
Cameron Carter, MD, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
The researchers, led by Anne Germain, PhD, at the University of Pittsburgh and Edward Pace-Schott, PhD, at Harvard Medical School and Massachusetts General Hospital, studied 150 healthy adults in the sleep laboratory. One third of the subjects got normal sleep, one third was sleep restricted so they only slept the first half of the night, and one third had no sleep so they got no sleep at all. In the morning, all subjects were subjected to fear conditioning.
Our team used a three-phase experimental model to capture and overcome fearful memories while their brain was scanned using functional magnetic resonance imaging.
Dr. Pace bulkhead.
In the conditioning paradigm, subjects were presented with three colors, two of which were paired with a light electric shock. After this fear conditioning, the subjects experienced an extinction of fear, with one of the colors presented without shocks to learn that it was now “safe”. That evening, the subjects were tested for their reactivity to the three colors, a measure of their fear of extinction or how well they had “forgotten” the threat.
The brain imaging recorded during the tasks showed activation in areas of the brain associated with emotional regulation, such as: B. in the prefrontal cortex, in people who had normal sleep. But brain activity looked very different in people with impaired sleep, said Dr. Pace bulkhead.
We found that among the three groups, those who had only slept half the night showed the greatest activity in areas of the brain associated with fear and the least activity in areas associated with controlling emotions.
Dr. Pace bulkhead
Surprisingly, people who did not get sleep lacked brain activation in fear-related areas during fear conditioning and extinction. During the extinction recall 12 hours later, her brain activity looked more similar to normal sleep, suggesting that a limited night of sleep might be worse than none at all.
The researchers suggest that sleeping only half the night results in a loss of sleep with rapid eye movements (REM), which has been shown to be important for memory consolidation and usually occurs towards the end of a normal sleep period.
The study used non-invasive brain imaging to give us a new window on how sleep deprivation disrupts normal mechanisms of fear extinction and potentially increases susceptibility to post-traumatic stress symptoms.
Medical workers and soldiers have often restricted or interrupted sleep instead of missing an entire night. Our results suggest that those who are partially sleep deprived are particularly prone to anxiety-related conditions such as post-traumatic stress disorder.
Dr. Pace bulkhead
Read press release
This study was funded by the Military Operational Medicine Research Program, Log # 11293006. PI: Germain.
About Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging is an official journal of the Society of Biological Psychiatry, whose aim is to promote excellence in scientific research and education in areas that study the nature, causes, mechanisms, and treatments of thought, emotional, or behavioral disorders will . In keeping with this mission, this peer-reviewed, fast-publishing international journal focuses on studies using the tools and constructs of cognitive neuroscience, including the full spectrum of non-invasive imaging and extra- and intracranial human physiological recording methods. Both fundamental and clinical studies are published, including those that consider genetic data, pharmacological challenges, and computational modeling approaches. The 2019 Impact Factor Score for Biological Psychiatry: Cognitive Neuroscience and Neuroimaging is 5.335. http://www.sobp.org/bpcnni
Rhiannon Bugno, editor
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
+1 254 522 9700