Neuropsychology of sleep and emotional coping: Why a 90 minute Nap Can Reset Your Emotional Coping Resources or Get an Unproductive Day Back on Track
A couple of weeks ago, I watched an interesting Fora.tv talk by psychology PhD Dr Matt Walker (a Professor at University of California, Berkley).
Most of the talk was about how sleep affects learning and memory. This is well established stuff that gets taught in undergraduate psychology classes. Basically, adequate sleep before learning is necessary to get your brain optimally ready for learning. And, adequate sleep after learning is necessarily to optimally process and synthesize the information you learned. Both chronic sleep deprivation and binge/starve sleep patterns interfere with optimal learning.
However, the part of the talk that was most interesting to me was his description of a study he had conducted with colleagues about sleep and emotions. The study is particularly relevant for people struggling with depression, anxiety, or stress. I’m going to explain the study and then follow with some practical recommendations.
What they did:
The study participants were divided into 2 groups.
One group was deprived of sleep. The other group got a normal night’s sleep.
The next day everybody in the study underwent a brain scan.
The brain scan was the type that measures what your brain is doing while you’re under the scanner.
During the brain scan, each participant was shown 100 different standardized pictures, one picture at a time. The pictures ranged from mildly unpleasant to extremely unpleasant. The set of pictures used has been purposely designed for triggering negative emotions.
When exposed to the negative emotion triggering pictures – the group who had been sleep deprived showed 60% higher reactivity of the amygdala. The amygdala is an important brain structure involved in generating negative emotions, in what Professor Walker refers to as the “neanderthal brain”. By neanderthal brain, he means the part of our brain that evolved early in our evolutionary history.
The researchers then asked – Why was the amygdala showing stronger activation when people were sleep deprived?
Their answer: They found another key difference in the brain reactions of people who had had enough sleep vs. sleep deprived people. For only the people who had had adequate sleep, when their amygdala was activated, another area of the brain – the medial pre frontal cortex – also started working harder.
The pre frontal cortex is a “new” part of the brain in our evolutionary history. It’s the part of the modern human brain that’s most different from caveman/neanderthal brains.
When people who had had enough sleep were exposed to the distressing pictures, the pre frontal cortex acted as a brake on the amygdala. The more-evolved part of the brain was helping dampen down the less-evolved part. The result was less activation of the amygdala and feeling calmer, but only for the group who had had adequate sleep.
For people in the sleep deprivation group, the pre frontal area wasn’t activating in response to the distressing pictures to the same extent.
Because of this, the sleep deprived people had more intense emotional responses to the negative emotion inducing pictures.
Take Home Messages:
1. If you’re struggling with negative emotions (depression, anxiety, stress) then adequate sleep is especially important.
When you have had adequate sleep you’ll be better able to cope with emotional and social demands. Your emotional reactions to negative events will be less intense because your pre frontal cortex will help calm your amygdala. It’s not just that you’ll make better choices about coping when you’re not sleep deprived, your brain reactions will mean the events/stress don’t feel so bad.
2. If you’re finding yourself having an unproductive day or an emotionally difficult day, try having a nap to get an emotional re-set. A nap of about 90 minutes (but not longer) is probably going to be necessary to give yourself the greatest emotional re-set benefits. This is because if you sleep 90 minutes you’ll go through one complete cycle of all five of the 5 stages of sleep, including REM sleep. REM sleep seems to be important for the emotional resetting process.
DON’T nap so long that it upsets your night time sleep or that you use sleep as a way of avoiding the day. For you, one complete cycle of all five stages of sleep might be a little longer than 90 mins but not longer than 2 hours.
When you get up, do something that gives you a sense of pleasure or mastery/accomplishment.
3. If you’re doing hard things (learning something, doing cognitively or emotionally demanding work, working in stressful circumstances, studying for exams etc), then adequate sleep will help with both learning and emotional coping.
If you want to watch the talk, it’s here at Fora.tv –