Just came across a nice little article by Ed Yong on how the two major phases of sleep — REM and slow-wave sleep — might contribute to creativity. These ideas have been floating around for a while, but it’s nice to see them in a pop sci article.
Here’s an excerpt:
“Let’s say you replay memories of birthday parties,” she says. “They all involve presents, cake, and maybe balloons. The areas of the brain that represent those things will be more strongly activated than areas that represent who was at each party, or other idiosyncrasies.” Over time, the details may fade from memory, while the gist remains. “That’s how you might form your representation of what a birthday party is.” (Some scientists have argued that dreaming is the conscious manifestation of this process; it’s effectively your brain watching itself replaying and transforming its own memories.)
This process happens all the time, but Lewis argues that it’s especially strong during SWS because of a tight connection between two parts of the brain. The first—the hippocampus—is a seahorse-shaped region in the middle of the brain that captures memories of events and places. The second—the neocortex—is the outer layer of the brain and, among other things, it’s where memories of facts, ideas, and concepts are stored. Lewis’s idea is that the hippocampus nudges the neocortex into replaying memories that are thematically related—that occur in the same place, or share some other detail. That makes it much easier for the neocortex to pull out common themes.
The other phase of sleep—REM, which stands for rapid eye movement—is very different. That Greek chorus of neurons that sang so synchronously during non-REM sleep descends into a cacophonous din, as various parts of the neocortex become activated, seemingly at random. Meanwhile, a chemical called acetylcholine—the same one that Loewi identified in his sleep-inspired work—floods the brain, disrupting the connection between the hippocampus and the neocortex, and placing both in an especially flexible state, where connections between neurons can be more easily formed, strengthened, or weakened.
Read the whole thing here.
Image: The Sleep of Reason Produced Monsters, by Francisco Goya