The most important findings of scientific dream research can be summarized in nine key points. Many important questions about dreaming remain unanswered, but these nine findings have solid empirical evidence to support them.
- Rapid eye movement (REM) sleep is a trigger for dreaming, but is not identical with dreaming. All mammals have sleep cycles in which their brains pass through various stages of REM and non-REM sleep. Dreaming seems to occur most often, and most intensely, in REM sleep, a time when many of the brain’s neuro-electrical systems have risen to peak levels of activation, as high as levels found in waking consciousness. However, dreaming occurs outside of REM sleep, too, so the two are not identical; REM sleep is neither necessary nor sufficient for dreaming.
- REM helps the brain grow. The fact that REM sleep ratios are at their highest early in childhood (newborns spend up to 80% of their sleep in REM, whereas adults usually have 20-25% of their sleep in REM) suggests that REM, and perhaps dreaming, have a role in neural maturation and psychological development.
- Dreaming also occurs during hypnogogic, hypnopompic, and non-REM stage 2 phases of sleep. In the transitional times when a person is falling asleep (hypnogogic) or waking up (hypnopompic), various kinds of dream experiences can occur. The same is true during the end of a normal night’s sleep cycle, when a person’s brain is alternating exclusively between REM and non-REM stage 2 phases of sleep, with a relatively high degree of brain activation throughout. Dreams from REM and non-REM stage 2 are difficult to distinguish at these times.
- The neuro-anatomical profile of REM sleep supports the experience of intense visionary imagery in dreaming. During REM sleep, when most but not all dreaming occurs, the human brain shifts into a different mode of regional activation. Areas of the prefrontal cortex involved in focused attention and rational thought become less active, while areas in the limbic system (involved in emotional processing, memory, and instinctive responses) and the occipital lobe (involved in visual imagination) become much more active. This suggests that the human brain is not only capable of generating intense visionary experiences in dreaming, it has been primed to do so on a regular basis.
- The recurrent patterns of dream content are often continuous with people’s concerns, activities, and beliefs in waking life. This is known as the “continuity” hypothesis, and it highlights the deep consistency of waking and dreaming modes of thought. People’s dreams tend to reflect the people and things they most care about in the waking world. A great deal of dream content involves familiar people, places, and activities in the individual’s waking life. The dreaming imagination is fully capable of portraying normal, realistic scenarios. This means dreaming is clearly not a process characterized by total incoherence, irrationality, or bizarreness.
- The discontinuities of dreaming, when things happen that do not correspond to a normal waking life concern, can signal the emergence of metaphorical insights. Research on the improbable, unreal, and extraordinary elements of dream content has shown that, on closer analysis, this material often has a figurative or metaphorical relationship to the dreamer’s waking life. Metaphorical themes and images in dreams have a long history in the realm of art and creativity, and current scientific research highlights the dynamic, unpredictable nature of dreaming as an endless generator of conceptual novelty and innovation.
- Dream recall is variable. Most people remember one to two dreams per week, although the memories often fade quickly if the dreams are not recorded in a journal. On average, younger people tend to remember more dreams than older people, and women more than men. Even people who rarely remember their dreams can often recall one or two unusual dreams from their lives, dreams with so much intensity and vividness they cannot be forgotten. Dream recall tends to respond to waking interest. The more people pay attention to their dreams, the more dreams they are likely to remember.
- Dreaming helps the mind to process information from waking life, especially experiences with a strong emotional charge. From a cognitive psychological perspective, dreaming functions to help the mind adapt to the external environment by evaluating perceptions, regulating emotional arousal, and rehearsing behavioral responses. Dreaming is like a psychological thermostat, pre-set to keep us healthy, balanced, and ready to react to both threats and opportunities in the waking world. Post-traumatic nightmares show what happens when an experience is too intense and painful to process in a normal way, knocking the whole system out of balance.
- The mind is capable of metacognition in dreaming, including lucid self-awareness. During sleep and dreaming the mind engages in many of the activities most associated with waking consciousness: reasoning, comparing, remembering, deciding, and monitoring one’s own thoughts and feelings. Lucid dreaming is one clear example of this, and so are dreams of watching oneself from an outside perspective. These kinds of metacognitive (thinking about thinking) functions were once thought to be impossible in dreaming, but current research has proven otherwise. Dreaming has available the full range of the mind’s metacognitive powers, although in different combinations from those typically active in ordinary waking consciousness.
For further reading:
Barrett, Deirdre and Patrick McNamara, ed.s. The New Science of Dreaming. Westport: ABC-Clio, 2007.
Bulkeley, Kelly. Big Dreams: The Science of Dreaming and the Origins of Religion. New York: Oxford University Press, 2016.
Domhoff, G. William. Finding Meaning in Dreams: A Quantitative Approach. New York: Plenum, 1996.
Hurd, Ryan and Kelly Bulkeley, ed.s. Lucid Dreaming: New Perspectives on Consciousness in Sleep. Westport: ABC-Clio, 2014.
Kryger, Meir H., Thomas Roth, and William C. Dement, ed.s. Principles and Practice of Sleep Medicine. Fourth Edition. Philadelphia: Elsevier Saunders, 2005.
Maquet, Pierre, Carlyle Smith, and Robert Stickgold, ed.s. Sleep and Brain Plasticity. New York: Oxford University Press, 2003.
Pace-Schott, Edward, Mark Solms, Mark Blagrove, and Stevan Harnad, ed.s. Sleep and Dreaming: Scientific Advances and Reconsiderations. Cambridge University Press, 2003.
Pagel, James. The Limits of Dream: A Scientific Exploration of the Mind/Brain Interface. New York: Academic Press, 2010.
Solms, Mark. The Neuropsychology of Dreams: A Clinico-Anatomical Study. Mahway: Lawrence Erlbaum, 1997.
Books about dreams are excellent holiday presents—easy to give and enjoyable to receive. They are widely available for purchase, fairly inexpensive, simple to wrap and ship, and sure to bring surprise and delight (and perhaps life-changing illumination) to their recipients. If you have a long list of people for whom you’re trying to buy gifts in the next few weeks, consider getting them one or more of these excellent new books, which have come out in 2017 or 2016.
Between January 8, 2015 and October 4, 2017, I remembered and recorded a dream every night for 1,001 consecutive nights. Now I’m studying the dreams and trying to find insights that can help in exploring the dream series of other people. I don’t expect anyone to accept my personal dreams as conclusive evidence for any general theory of human dreaming. Instead, I offer them as way of being transparent about the experiential grounding of my research pursuits. This is one of the ways I get ideas for new projects.
Most of these inferences—I’d say 11 of 13—are unmistakably accurate in identifying a continuity between a pattern of dream content and an aspect of my waking life concerns. The two I would question are numbers 10 and 12. Regarding the low frequency of dream references to school, I do in fact engage in a great deal of teaching and educational work, but it’s almost entirely online, and I rarely set foot inside a traditional school any more. Also, I no longer have school-age children living at home. So it seems my dreams are continuous with my physical behaviors relating to schools, but not with my computer-mediated educational activities.
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All life on earth is fundamentally oriented toward the cyclical presence and absence of the sun. Every kind of living being has evolved internal clocks of approximately 24 hours in length that guide and regulate their biological processes and behaviors. These internal clocks are known as circadian rhythms, and they have long been observed as powerful factors in plant and animal life. But only recently have the details of how these clocks work become known, thanks to the work of this year’s trio of prize winners. Their studies, going back to the 1980’s, explain how circadian rhythms are programmed into the genetic activities of each cell at the molecular level.
It may also give us new insights into the rhythms, cycles, and recurrent patterns in human dreaming. Anything that gives a new understanding of sleep has the potential to provide a new understanding of dreams, since dreaming naturally emerges out of the state of sleep. The ubiquity of dreaming in human experience throughout recorded history, in cultures all over the world, strongly suggests it is a phenomenon deeply rooted in our evolutionary heritage. It strengthens the argument in favor of this idea to show, as this year’s Nobel winners have done, that the circadian rhythms guiding our waking and sleeping behaviors are encoded in every cell in our bodies. There can no longer be any question that sleep is an absolutely vital feature of healthy human life. The study of dreams can build on this solid foundation in evolutionary biology to explore in more detail what exactly is happening in the mind and body during sleep that contributes so powerfully to human health.
In the next scene a supremely confident Master Ford brings a group of companions to his house to apprehend Falstaff. His wife, in the midst of sending out the dirty laundry, denies that Sir John is there. Master Ford contemplates the laundry basket, which is about to be sent out for “buck-washing” (a traditional means of laundering clothes by soaking and rinsing them repeatedly with lye, ash, or urine), and utters some strange lines: “Buck? I would I could wash myself of the buck! Buck, buck, buck! Ay, buck; I warrant you, buck—and of the season too, it shall appear” (III.iii.155-157).