British researchers proved that sleep deprivation reduces the brain’s ability to suppress unwanted memories and intrusive thoughts.
Along with colleagues at the University of East Anglia, Scott Caimey of the University of York demonstrated that sleep deprivation interferes with the ability of the prefrontal area of the brain to filter memories.
The test used brain scans to examine the brain activity of 85 adults. Half had had a normal night’s sleep in a sleep lab; the other half were kept awake all night.
The subjects were then asked to look at faces they had seen before in combination with emotionally charged images, such as pictures of a car accident or of a fight. For each face, they were asked to either recall the corresponding scene or suppress the memory of it.
Filter
Whenever the equipped participants tried to suppress the images of the accident or of the fight, the researchers saw more activity in the brain regions that control thoughts and emotions. There was significantly less activity in the hippocampus (=the brain area involved in memory retrieval) when they tried to suppress unwanted memories. According to the researchers, this shows that they were able to turn off the retrieval operations that underlie emerging intrusive thoughts.
In turn, the participants who had stayed awake all night were unable to activate the area in the brain that helps us suppress unwanted memories, according to Camey.
Improving sleep
“Now that we have a better understanding of the mechanisms in the brain that can help filter negative memories and thoughts, we may be able to work on more targeted treatments and behavioral therapies that help improve sleep,” he said. “In this way, it may be possible to support the brain in what it does so cleverly and what allows us to live a stable mental life.”
