Dreams are very weird, if you think about it: you're hallucinating four to six times a night as your brain attempts to synthesize and understand your experiences and memories. Recurring dreams add another layer of mystery. Around 60 to 70% of adults report having at least one recurring dream in their lifetime, which begs the question: what is the brain doing when it plays the same dream, again and again? The neuroscience of recurring dreams gives us some insight into how they happen.
Brain activity during a recurring dream partly depends on the dream's content. "Different parts of the brain may be activated by different dreams," Dr. Clifford Segil, D.O., a neurologist at Providence Saint John's Health Center, tells Bustle. "For example, dreams which are very visual activate our occipital cortex. Dreams which involve dancing at a disco would activate our auditory cortex." Dreaming of the same thing every night, he says, means you'll activate the same group of structures repeatedly.
Emotions play a role in recurring dreams, too. "One of the theories regarding the function of dreams is that dreaming permits the emotional content of experiences to be processed," Dr. Guy Leschziner, M.D., consultant neurologist at London Bridge Hospital and clinical lead at Guy's Hospital Sleep Disorders Center, tells Bustle. If a dream keeps coming back, its emotional content is clearly important to you. This is why one of the most important mechanisms for generating dreams is the limbic pathway, an electrical brain circuit that regulates our emotional and behavioral responses when we're awake. "When a person experiences recurring dreams, the limbic pathway is being activated in the brain," Segil says. And it often lights up the amygdala, an almond-shaped area that processes emotions.
Along with the amygdala and the limbic system in general, repeating dreams can also involve the reticular activating system, or RAS. It's a part of the brainstem that filters information to help us focus on important things, like emotional issues.
Research published in Motivation and Emotion in 2017 showed that recurring dreams might occur because of something called psychological need frustration, where you're not getting what you need from waking life — whether it's feeling respected, close to others, or in control. They can also be based on memories or traumas from your past. The RAS, the limbic system, and the amygdala combine to make the same dreams resurface again and again, Segil says, as your brain grapples with processing your problems and finding a solution.
There's another neurological reason dreams can keep coming back, too. "People with post-traumatic stress disorder will very frequently have recurring dreams or nightmares related to the trauma, and it is proposed that because of the extreme emotion of the experience, people wake up during the dream," Leschziner says. "This means that the dreaming process is never completed, and the emotional memory is never fully processed." The brain will keep trying to finish its nocturnal job, and get interrupted every time. This could happen with benign dreams, too, Leschziner says.
There's still a lot about recurring dreams, and dreaming in general, that science doesn't understand. "These ‘systems’ or ‘pathways’ remain complicated and perplexing, even in the year 2020," Segil says. Your recurring dreams might be annoying or strange, but they could show that something's "stuck" in your waking life. And that could be a valuable clue to finding some peace, day and night.
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