Every night of our lives, we become "flagrantly psychotic," according to sleep expert Matthew Walker.
Walker is a professor of neuroscience and psychology at the University of California, Berkeley, where he's the director of the sleep and neuroimaging lab, and the author of the recent book "Why We Sleep: Unlocking the Power of Sleep and Dreams."
Dreams are those times during the night that we lose a grip on reality for reasons humanity has tried to understand for millennia. But these aren't just hallucinatory episodes that explore the strangest corners and cobwebs of our minds. They serve a real function, according to Walker. Dreams help us process emotions and solve problems.
Walker's declaration that we all become psychotic on a nightly basis might seem inflammatory.
But as he writes, when we dream we hallucinate, seeing and hearing things that aren't there. We're deluded into thinking these things are real at the time. We're disoriented about time and place and even our own identity. We experience emotional swings for no apparent reason. And when we wake, for the most part, we experience amnesia and forget it all. We'd certainly call that behaviour psychotic during the day.
That amnesia part is why many people don't even realise that they dream. But we all do, every night. For the most part, what we call dreams occur during REM sleep.
For a time at least, neuroscientists thought it possible that dreams were simply phenomena that would arise because of what our brains were doing at that time of night. Now, we're learning that even though REM sleep has functions, the dreams that happen during that sleep might may have separate functions as well.
As Walker wrote in his book, MRI research has shown that when people are in REM sleep, parts of the brain associated with visual perception, movement, memory, and emotion all become very active. At the same time, parts of our brain associated with logic and order become deactivated.
In other words, we know what's going on in REM, thanks to brain scanning - emotion, visual imagery, memory are all kicked into full gear, without the corresponding logical director that helps keep those things in check during the day.
The question is why.
Throughout history, humans have interpreted dreams in a number of ways. The Egyptians and Greeks thought they were messages or visits from the gods, at least until Aristotle theorised that these strange phenomena originated in our day-to-day lives.
According to Walker, Freud was the first to truly place dreams into the domain of what we would now call neuroscience. Yet Freud also thought dreams represented unconscious desires and could be interpreted to reveal our true wants.
Freud's ideas that dreams could somehow be decoded don't match up to modern neuroscience. It's not that it isn't worth thinking about what your dreams might mean, according to Walker. It's just that no one has ever found a reliable way to say that a dream about a certain thing (searching for a lost object, for example) has a concrete corresponding meaning in the waking world.
We do know from brain researchers that there is a connection between dreams and our lives. A tiny percentage of the dreams that people can remember in studies actually have to do with what that person was doing in the previous days. But a significant percentage of those dreams (between 35% and 55% in at least one study Walker cites) deal with emotions that a person has been experiencing in their day-to-day life.
Walker's research has revealed that at least one of the functions of dreaming is that it "removes the emotional sharp edges of our daily lives," he wrote. When having people view emotional images and then view them again 12 hours later, either later in the same day (if they saw them in the morning) or the next morning (if they saw them at night), having time to dream and digest these experiences significantly changes the way people react to them. People who have had time to dream become far less stressed out by the experiences.
Studies of those people's brain chemistry at night revealed that the more time people spent dreaming, the better they were at viewing those images without being stressed out. Follow up research on veterans with PTSD revealed that giving them medication that improves REM sleep also helped reduce nightmares and flashbacks.
Other research has indicated that dreaming helps people achieve creative breakthroughs and solve problems.
Studies with students that are woken up from REM sleep - from dreaming - show that their problem-solving capacity for anagram puzzles shoots up between 15 and 35% immediately following this sleep, and that they solve puzzles more quickly.
Further evaluation of those students shows that methods they use to solve puzzles while their brains are in this state of mind ignore the logical methods they might try during the day. Instead, they jump to innovative and non-logical solutions that turn out to be remarkably successful.
Walker says that other studies have shown that people who are trying to solve a problem with a hidden shortcut to a solution are three times as likely to discover that solution after a night's rest that those who had the same amount of time to think about it during the day.
This may be why people tend to wake from dreams with "eureka" moments about problems they've been puzzling through.
For both problem-solving and emotional healing purposes, the best solution really may be to sleep - and hopefully dream - on it.