Sleep is crucial for both physical and mental health. Many studies have revealed a link between a restful night of sleep and improved memory, as well as the removal of toxic proteins from the brain. Now a new link has been observed between sleep struggles and a person's ability to let go of emotional distress.
Researchers at the Netherlands Institute for Neuroscience have found evidence that suggests that people who suffer from insomnia fail to cope with shameful memories. As reported in the journal Brain, the team put participants in an MRI scanner and then asked them to relive embarrassing episodes from decades ago. The scans showed that good sleepers have neutralized those memories, but people suffering from insomnia have not. Neutralization, in this case, means the memory is comparable in response to a neutral stimulus.
This result may not seem surprising at first, but the study suggests that long-term difficulty in dealing with negative emotions plays a crucial role in sleep difficulties. And since insomnia is a primary risk factor in disorders of mood, anxiety, and PTSD, understanding its cause could help a large number of people. The authors suggest that insomnia might be associated with the areas of the brain that regulate emotions.
“Sayings like ‘sleeping on it’ to ‘get things off your mind’ reflect our nocturnal digestion of daytime experiences. Brain research now shows that only good sleepers profit from sleep when it comes to shedding emotional tension. The process does not work well in people with insomnia. In fact, their restless nights can even make them feel worse,” first author Rick Wassing said in a statement.
The team also conducted another study connecting sleep and the ability of participants to neutralize embarrassing memories. The researchers asked 64 people to sing a song karaoke-style while wearing special headphones that made it impossible for them to hear their own voice and find the correct pitch. They were then made to listen back to the recording and reveal their feelings about it. This was repeated four times over three consecutive days.
People who had a good night's sleep felt less shame about the recording than those who suffer from insomnia, whose feelings worsened over time. These findings, published in the journal Sleep, provide more evidence to bolster the link between insomnia and upsetting feelings.
The study has certain limitations in terms of gender, access to sleep history, as well as the fact that embarrassment about novel and relived experiences do not stem from the same area of the brain. A further limitation is that the participants came from the Netherland Sleep Registry and are not a random sample of the general population.