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What Does Science Know About Dreams?

Many questions still remain and more research needs to be done, but it's misleading at best and intellectually lazy at worst to suggest there is no good scientific evidence about the nature of dream content. What, then, does science actually know about dreams?
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I recently attended a public lecture by a famous neuroscientist, with several hundred other people in the audience. The topic of his talk was the unconscious brain processes that shape our conscious mental lives. The lecture was a good introduction to mainstream neuroscience, and the audience clearly enjoyed it.

At the end of his prepared remarks, the neuroscientist took written questions from the audience. The second question he was asked (which the moderator said came from several people) had to do with dreaming. What does science know about dreams?

From where I sat, the neuroscientist looked distinctly uncomfortable trying to answer this question. He started by saying, "Dream content is not well understood." He brought up hypnosis and meditation as other types of anomalous brain functioning that may have something to do with creativity, but he quickly dismissed them as "parlor tricks" unworthy of serious investigation. Returning to the question of dreams, he said they were probably just a "mish-mash" of the brain's "machine code" that we can't and shouldn't try to understand. This brought him back to a point he'd made earlier, namely discouraging people from spending too much time delving into their own unconscious minds. Consciousness, he said, is like a CEO who shouldn't try to micromanage all the lower-level activities of his company because that would be disruptive and distract him from his proper focus on the big picture.

The moderator asked him if he paid attention to his own dreams, and the neuroscientist seemed relieved at finally being able to admit the truth: "You know, I can't stand dreaming. It makes no sense to me." The moderator said something to the effect of, so you're an expert on the unconscious who can't stand his dreams? The neuroscientist shrugged. There was a bit of nervous laughter from the audience, and the moderator went on to the next question.

I'm not using the neuroscientist's name because the problem I want to discuss isn't just about him, but about an unfortunate combination of bias and ignorance I suspect is more widespread than it should be in the neuroscience community.

The problem starts with the assertion, "Dream content is not well understood." That's simply wrong. Several decades of scientific research on dreaming has identified a number of basic patterns in dream content, giving us a reasonably clear view of the meaningful features of dreaming experience. Many questions still remain and more research needs to be done, but it's misleading at best and intellectually lazy at worst to suggest there is no good scientific evidence about the nature of dream content.

What, then, does science actually know about dreams?

  1. Most dreams turn out to be rather mundane. Contrary to the common misconception that dreams are nothing but a "mish-mash" of random nonsense and bizarre fantasy, research shows that dreams usually include fairly realistic portrayals of familiar people, places, and activities. (David Foulkes was one of the first researchers to make this point.)

  • Many aspects of dream content are accurate, honest reflections of people's emotional concerns in waking life. Whatever you care most about in waking life, it's likely to appear with special frequency in the content of your dreams. (See, for example, G. William Domhoff's work on the "continuity hypothesis.")
  • The graphic, repetitive nightmares suffered by victims of post-traumatic stress disorder (PTSD) often change, in the course of healing, to more ordinary nightmares with a more diffuse range of imagery. As Deirdre Barrett says in her 1996 edited book Trauma and Dreams: "[A]s time passes, and especially for those whose PTSD is gradually improving, the dream content begins to make the trauma more symbolic and to interweave it with concerns from the dreamer's daily life." (p. 3)
  • These are three straightforward findings of contemporary dream research. They are not esoteric or obscure. They have been produced by well-trained psychologists, published in reputable books and journals, and cited frequently by other scholars. Combined with other solid scientific findings (see the additional references below), they suggest that dreaming is creatively structured by a network of emotional and cognitive processes that also operate in waking consciousness and have meaningful connections to our health and development.

    It's okay if neuroscientists aren't interested in their own personal dreams. But it's not okay to shift from "I don't understand my dreams" to "Dream content is not well understood." The shift to a passive voice makes this claim sound like a fact-based conclusion of mainstream science, whereas it really indicates a failure to engage with the abundant evidence generated by more than half a century of empirical dream research.

    Note: All quotes unless otherwise indicated come from my hand-written notes during the lecture.

    Other good sources on the science of dreams include works by Patrick McNamara and Deirdre Barrett, Edward Pace-Schott et al., Ernest Hartmann, Milton Kramer, Rosalind Cartwright, and the journal Dreaming.