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Reuters/Mark Makela
There’s a surprisingly logical pattern to who appears in our dreams.
SCIENCE OF SLEEP

Facebook for dreams: Scientists are mapping your brain’s social networks

You’ve probably played Six Degrees of Kevin Bacon—a game based on the premise that any actor in Hollywood can be connected back to the prolific Footloose actor within six movies or less. New research suggests that this is true not just of movie stars, but of the people in our dreams.

Using an enormous database of people’s dreams called DreamBank, Purdue University psychologists are mapping the social networks of our dream worlds. In a study published earlier this year in Cognitive Science, they analyzed 1,397 dreams from five people, drawing out complex webs of how the people who appear in our dreams are related.

Psychologists compared the structure of those dream networks to what a random network of participants’ acquaintances would look like. The result? The connections between the people who show up in our dreams are surprisingly orderly.

The connections between the people who show up in our dreams are surprisingly orderly.

Just as in real life, the people in your dreams can be easily connected with one another through just a few steps. For instance, your aunt Amy may not have interacted directly with your childhood best friend Bobby in a dream. But they’re connected because both of them have appeared in dreams alongside your third-grade teacher Mrs. Cunningham.

People who have fewer degrees of separation from one another are also more likely to appear in dreams together.

“In waking life, if two people have a friend in common, those two people are likely to know each other,” explains Richard Schweickert, a professor of psychological sciences at Purdue University and supervising author of this new work. “We find the same thing in the dream social networks–if A is in a dream with B, and B is in a dream with C, then it’s quite likely that A is in a dream with C as well.”

This is the latest evidence to refute the theory that dreams are the result of random brain activity during sleep. Rather, the dreaming brain appears to call up memories in a more systematic manner. The more we understand about this process, the closer we’ll get to understanding how dreams are generated and why we dream in the first place.

One theory about why we dream is that it’s a way for our brain to consolidate the past day’s memories.

One theory about why we dream is that it’s a way for our brain to consolidate the past day’s memories. Studies show that people often do better on memory tasks such as recalling lists of random words after sleeping on it.

But we don’t typically think about word lists during our waking or dreaming hours. As social creatures, we do spend a lot of time mulling over our connections with others. So studying our dead relatives’ cameo appearances in our dreams can actually be a more fruitful way to figure out how our brains deal with memories during sleep.

“I think a good place to look for patterns is to look at what’s happening to people in dreams,” Schweickert says.

Of course, it’s hard to draw general conclusions after studying only five people’s dreams. But the Purdue research opens up some interesting questions for future study, such as how much dream structure varies from person to person.

Jumping from person to person in dreams could be a way for the brain to consolidate and map out social terrain.

Schweickert’s next project will be figuring out why we seem to jump from person to person in dreams, so that one moment we’re on a road trip with our old physics professor and the next it’s our next-door neighbor behind the driver’s seat. “It’s as if the dreamer is taking a random walk through their memory for people,” Schweickert says.

One hypothesis these “random walks” could be a way for the brain to consolidate and map out social terrain, such as who’s in your social network and how those people are connected with one another.

Schweickert compares this to the process of webpage indexing. “To make an index of pages, web crawlers basically go to a page and follow a link to another page, then another age, and keep following links,” Schweickert said. “Perhaps during a dream, one might be making a kind of index to your memory for people.”

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