Sleep soothes the traumatic memories

They say that sleep is restorative. Now scientists have discovered that sleep really helps the brain process emotional experiences and relieve traumatic memories

U.S. scientists discovered that sleep helps the brain process emotional experiences and to relieve the traumatic memories.
In experiments with individuals undergoing brain scans researchers at the University of California at Berkeley, found that the chemical signals that cause stress are turned off during sleep.
This occurs during a phase known as 'rapid eye movement sleep' or REM, which occur most often dreams or daydreams.
The researchers, who published the study in Current Biology, conducted experiments in which volunteers were shown several disturbing images during two sessions.
They found that they could sleep between one session and another managed to better process the emotional reaction that produced the image a second time.
The results, scientists say, show that there is a link between sleep and memory.
And they explain why people with posttraumatic stress disorder (PTSD) and war veterans have many difficulties to recover from the painful experiences and suffered recurring nightmares.
The study also provides valuable information about why we dream.
REM Sleep
Most people have to deal with traumatic events at some point in their lives and, for some, these events can cause PTSD.
This disease can cause serious disruptions in the person even long after the event occurred.
There is substantial evidence that 20% of our dream, which is the REM stage, plays a significant role in the processing of recent memories.
And scientists believe that if we can better understand this process may eventually help patients with PTSD.
For the study, researchers recruited 35 volunteers and divided them into two groups.
After showing disturbing 150 images designed to provoke an emotional reaction, allowed one of the groups had a night of 'good sleep'.
While sleeping they were subjected to MRI scans to measure blood flow in the brain, which is a method to observe which brain regions are most active.
Then returned to teach the same images a second time.
The results showed that seeing the images for the second time those who slept properly showed less activity in the amygdala, a brain region associated with emotions, and more activity in the prefrontal cortex, the region associated with rational thought.
Those who did not sleep showed a response 'more emotional' at seeing the images.
Researchers believe that chemical changes that occur in the brain during REM sleep explains how the body fails to process stress better.
"We know that during REM sleep there is a marked decrease in the levels of norepinephrine (noradrenaline), a brain chemical associated with stress" explains Dr. Matthew Walker, who led the study.
'When processing emotional experiences earlier in this environment-safe neurochemically low-norepinephrine during REM sleep, woke up the next day and the emotional power of these experiences is softened'.
"We feel better about these events and we think we can deal with them" adds the scientist.
But Dr Roderick Orner, a specialist in clinical psychology, told the BBC that although it is believed that sleep plays a crucial role in the processing of traumatic memories is likely there are many other factors that cause PTSD patients.
'In more severe cases of trauma could be very difficult for the patient to process these experiences during sleep, especially if the event has had a major impact on a person's daily life' expresses the expert.
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