Insomnia and Emotional Memories Linked
Situations like being bullied at school, getting fired from a job or losing your train of thought during an important speech can feel mortifying when they occur. But in time, and with the help of sleep, the shame and embarrassment fade away. You can recall the experience without re-experiencing the emotional charge.
This may not be the case for people with insomnia, results of a new study in the journal Brain suggest. Insomnia may involve disruption of the brain’s processing of emotional experience, burdening poor sleepers with emotionally charged memories. Here’s more about it.
Biological Aspects of Insomnia
Insomnia used to be blamed mainly on bad habits and faulty thinking, but increasing attention is being paid to biological factors that underlie insomnia. Results of gene studies point to genetic factors that make people vulnerable to insomnia. Many insomnia risk genes are located in the limbic area of the brain, where the processing of emotion occurs. The possibility that insomnia has to do with disturbed emotion processing is what researchers in The Netherlands set out to investigate.
Movies of the Brain Are Confirmatory
From the functional MRIs, investigators found the following:
The shame participants felt as they listened to their own singing triggered intense limbic activity in the brains of both normal sleepers and people with insomnia
Although memories of past shameful experiences did not induce a limbic response in normal sleepers, in insomnia sufferers, they did. In fact, in the brains of people with insomnia, limbic activity was noted in many of the same areas active during novel emotional experiences, notably, the anterior cingulate cortex.
“The findings,” write the authors, “suggest that normal sleepers activate a markedly different brain circuit while reliving emotional memories from the distant past as compared to when they are exposed to novel emotional experiences. In patients with insomnia, however, the brain circuits recruited with reliving distant emotional memories overlapped with the circuits recruited during a novel emotional experience.”
The restless REM sleep that often characterizes insomnia may be attributable to a failure to deactivate a part of the brain that, if shut down, could enable more restorative sleep and quicker recovery from emotionally painful experiences. There are ways to treat insomnia behaviorally, and some work pretty well. But only when more research into the causes of insomnia is conducted will researchers be able to find a cure.