The benefits of dreaming

Carolyn Todd. REM Sleep Is Magical. Here’s What the Experts Know. NYTimes. Feb 25, 2023.

When we sleep we go cycle through five stages of sleep. We dream during one of those stages. When we dream we move our eyes. Thus dream sleep is called REM sleep – Rapid Eye Movement.

Benefits:

If you’ve ever gone to bed upset about something and woken up noticeably less bothered, it’s likely a result of the emotional processing and memory reconsolidation that happen during REM. There’s evidence that your brain divorces memories from their emotional charge — removing the “sharp, painful edges” from life’s difficulties, said Matthew Walker, a professor of neuroscience and psychology and the founder and director of the Center for Human Sleep Science at the University of California, Berkeley. REM is “like a form of overnight therapy,” he said.

REM also makes us better learners. During this sleep stage, your brain strengthens neural connections formed by the previous day’s experiences and integrates them into existing networks, Dr. Robbins said.

Dr. Walker added: “We take those new pieces of information and start colliding them with our back catalog of stored information. It’s almost a form of informational alchemy.”

These novel connections also make us more creative, he said. “We wake up with a revised mind-wide web of associations” that helps us solve problems. Researchers in Dr. Walker’s lab conducted a small study where people were roused from different stages of sleep and asked to solve anagram puzzles. They found that subjects awakened from REM sleep solved 32 percent more anagrams than subjects who were interrupted during non-REM sleep.

Then, of course, there’s dreaming: The majority of our vivid dreaming takes place during REM. Some experts suspect that dreams are a mere byproduct of REM sleep — the mental manifestation of neurological work. But others think they might help people process painful experiences, Dr. Walker said.

And although most physical processes, like repairing bone and muscle tissues, happen during the non-REM sleep stages, some hormonal changes occur while someone is in REM, Dr. Walker said, like the release of testosterone (which peaks at the onset of the first REM cycle).

If we don't get enough:

But large deficits of REM sleep, no matter your age, can deprive you of its psychological benefits, Dr. Dasgupta said. You may have more trouble learning, processing emotional experiences or solving problems.

Dysregulated REM sleep is also linked with cognitive and mental health issues, like slower thinking and depression, said Dr. Ana Krieger, medical director of the Center for Sleep Medicine at Weill Cornell Medicine. Too little REM, fragmented REM and REM sleep behavior disorder — where muscle paralysis fails to happen and people physically act out their dreams, often by kicking or punching — are associated with neurological issues, from mild forgetfulness to dementia and Parkinson’s disease.

There's more at the link.