Psychology and Brain-Mind Science Archives | Page 6 of 10

March 23, 2017

The Study of a 32-Year Long Dream Journal

The latest series to be uploaded into the Sleep and Dream Database (SDDb) is the biggest yet: the “Brianna Journal 1984-2016,” 2,448 dream reports from a woman who kept a journal fairly consistently for 32 years. This series offers an amazing opportunity to observe in unusually close detail the emotional contours of an individual’s life as she makes her way through a challenging and often dangerous world.

Brianna (not her real name) shared these dreams with me and Deirdre Barrett last year, which we initially studied for a presentation at the 2016 conference of the International Association for the Study of Dreams. Using the word search functions of the SDDb, I performed a “blind analysis” on three subsets of Brianna’s dream journals, meaning I 1) tabulated the frequencies of word usage for several categories of dream content, 2) compared her frequencies with baseline averages for each category, and 3) made inferences, based on nothing other than her dream patterns, about her concerns and activities in waking life. For instance, I inferred that Brianna is closer to her mother than her father, is interested in books and writing, is not interested in sports, and has significant involvement with issues of death and dying. Brianna herself, who attended the conference presentation, confirmed these and other inferences, which helped demonstrate the general idea that patterns in dreaming can accurately reflect people’s waking life concerns.

Now I have finally uploaded the complete collection of dreams Brianna shared with me, which provides a broader overview of her dreaming experiences over the span of more than three decades. I will share more details from my analysis at the upcoming 2017 IASD conference (held in Anaheim, California, June 16-20). For now, here are some of the initial findings of my study of this remarkable series.

Length: This is a long series in at least three ways: total number of dreams (2,448), time span covered by the journals (32 years), and average number of words per report (292). The median word length is 168 words, meaning half the reports are shorter than that, and half the reports are longer. Looking at the distribution of word lengths in the series as a whole, 851 of the dreams have between 1 and 99 words, 794 of the dreams have between 100 and 299 words, and 803 of the dreams have 300 or more words. A series with this many dreams at both the short and long ends of the spectrum poses special challenges for analysis. For now, I will study the series as a whole, but at some point I will look at subsets of varying lengths (e.g., the dreams of 50-300 words in length, of which there are 1,192).

Cognition: The series as a whole has a remarkably high frequency of dreams with at least one word relating to thinking (71%), speaking (56%), and reading/writing (19%). The dreams have lots of strange, irrational material, too, but much of the content is oriented around normal cognitive activities that are also important in her waking life (Brianna is, in fact, a literate, well-educated, and sociable person). The high proportion of cognition references could be a result of the unusual length of her dreams, and/or it could be an accurate reflection of her waking personality. Either way, this is a topic worth further investigation.

Death: One out of every seven (15%) of Brianna’s dreams has a reference to death. That is quite high compared to other dream series I have studied, and it strongly suggests that death and dying are major concerns in Brianna’s waking life. I know enough about her to confirm the general accuracy of this inference, and now I am curious to look more closely at how this theme weaves its way through her series as a whole.

Religion: The frequency of references to religion is also unusually high in this series, and the list of specific words used in the dreams makes it fairly easy to accurately infer that Brianna is Jewish. In previous studies I have found that patterns in dreaming offer good clues to a person’s beliefs and attitudes towards religion. The Brianna series seems to be another illustration of that premise, and through deeper analysis I hope to understand better how religious and spiritual themes in the dreams track with Brianna’s waking life interests, concerns, and experiences.

Note: this post was originally published in Psychology Today, March 10, 2017.

January 25, 2017March 1, 2017

Dreaming Is Play: A New Theory of Dream Psychology

images The scientific study of dreams has fallen on hard times. In an era dominated by cognitive-behavioral therapy, psychoactive drugs, and computer models of the mind, dreaming seems less relevant to psychology today than at any time since Sigmund Freud published The Interpretation of Dreams in 1900.

The problem, ironically, is not a lack of empirical evidence about the nature and function of dreams. Rather, the problem is too much evidence that does not seem to add up to a coherent theory or a useful guide for therapeutic practice.

Psychoanalysts from Freud onwards have used clinical case studies to argue that dreams, despite their cryptic symbolism, are meaningful and can be tremendously helpful in therapy. In the 1950’s, however, neuroscientists discovered that dreaming correlates with automatic processes in the brain during sleep, suggesting that dreams are in fact nothing but neural nonsense. At about the same time, quantitative researchers began using statistical methods to analyze tens of thousands of dream reports. Instead of bizarre symbols or random nonsense, these researchers found a large number of clear, straightforward continuities between dream content and people’s emotional concerns in waking life.

The results from each of these areas of research appear to contradict the other two, making the quest for common ground all the more difficult.

New developments in cognitive science offer a better way forward, by illuminating the evolutionary features of the human mind as they relate to the survival needs and adaptive challenges facing our species. When we look at dreaming in this broader context, a simple yet powerful thesis emerges: dreaming is a kind of play, the play of the imagination in sleep.

Zoologists have found evidence of play behaviors in all mammals, especially among the youngest members of each species. Play occurs within a temporary space of pretense and make-believe where actions are not bound by the same constraints that govern the normal, non-play world. A major function of play, most researchers agree, is to practice responses to survival-related situations in a safe environment, so the young will be better prepared when they become adults to face those situations in waking reality. Creativity, flexibility, and instinctual freedom are the hallmarks of play, in humans as well as other animals.

All of these qualities of play are prominent in dreaming, too. Dreaming occurs within sleep, a state of temporary withdrawal from the waking world in which the imagination is given free reign to wander where it will. Dreaming tends to be more frequent and impactful in childhood; young people experience dreams of chasing, flying, and lucid awareness much more often than do older people. The contents of dreams often have direct references to survival-related themes like sexuality, aggression, personal health, social relations, and the threat of death. Although dreams in general are not as wildly bizarre as often assumed, they do have the qualities of spontaneous creativity and rich variation that stimulate the mind to look beyond what is to imagine what might be.

Thinking about dreaming as a kind of play has many advantages, foremost of which is overcoming the conflicts between the different branches of dream research. Dreaming is indeed rooted in natural cycles of brain activity, as neuroscientists have argued, but it no longer makes sense to treat dreams as meaningless by-products of a sleep-addled mind. If we saw a group of children playing an imaginary game of house, would we be justified in assuming their brains are somehow malfunctioning? Not at all. In the same way, we should recognize the playful qualities of dreaming as integral to healthy cognitive functioning. In the language of computer programming, dreaming should be appreciated as a vital feature of the mind, not a bug to be fixed or eliminated.

A dreaming-is-play perspective has clear benefits for the practice of psychotherapy. Rather than laboring to uncover deep hidden messages, therapists can explore the imaginative dynamics of their clients’ dreams for useful clues to their emotional concerns and waking life challenges (while still pursuing deeper symbolic levels, if so desired).

This can be especially helpful in caring for trauma patients. Research on post-traumatic stress disorder (PTSD) has shown that during successful treatment the patients’ recurrent nightmares gradually become less fixated on the trauma and more open to an increasing variety of dream themes, characters, and scenarios. In other words, the more playful their dreams become, the more progress the patients are making towards psychological health.

I once did a research project with a woman, “Nan,” who was nearly killed in a car accident and spent several days in intensive care with severe spinal injuries. Her dreams following the accident were filled with fear, aggression, and misfortune, exactly what we would expect of someone with acute PTSD. But Nan told me she put her hopes on one unusual dream, which came about four months after she was hurt. In this dream there was a magical paintbrush that allowed her to paint the colors of the rainbow, just like a beloved character she remembered from a childhood story. This was the first time since Nan’s accident that one of her dreams had so many references to colors, positive emotions, and good fortunes. The green shoots of playfulness that emerged in this dream anticipated, and perhaps even stimulated, her eventual recovery of health.

The evolutionary success of our species is largely due to the tremendous flexibility and adaptive creativity of our minds. Current scientific evidence is telling us that dreaming is a powerful, neurologically hard-wired process that strengthens precisely those distinctively human psychological abilities. Our playful reveries during sleep function like mental yoga: stretching our cognitive abilities in new directions, exploring the boundaries and potentials of awareness, and preparing us for whatever the waking world may bring.

October 5, 2016

Review of the 2016 Conference of the International Association for the Study of Dreams

rolduc At this year’s annual conference of the International Association for the Study of Dreams (IASD), held June 24-28 in Kerkrade, the Netherlands, the world’s leading dream researchers gathered to share their latest findings. The conference ran for four and a half days, with six or seven simultaneous tracks of events going on from morning through the evening. It was truly a feast of dreaming!

Every year it takes me a while to process and digest all the events, conversations, and impressions that occurred during the conference. It’s way too much to take in while there, so I try to keep notes and then reflect on them over the summer and fall. As I look through my notes from this year, these strike me as the highlights from the latest IASD gathering:

Iain Edgar, an anthropologist at Durham University in the UK, gave a chilling presentation on his investigations into the dream beliefs and practices of Islamic jihadists, who are using social media with remarkable effectiveness to share their violent dreams and encourage others to do so as well.

Pilleriin Sikka, a lecturer in cognitive neuroscience at the University of Skovde in Sweden, described the challenges of accurately measuring emotional content in dreams. (A current debate in the field: are dreams predominated by negative emotions, or do dreams have a roughly even balance of positive and negative emotions?) Her study highlighted the importance of transparency in the methods used for studying this aspect of dreaming, because different methods often yield different results.

Nils Sandman, a doctoral student at the University of Turku in Finland, reported on a national demographic study in Finland that found higher nightmare frequency is associated with insomnia, depression, low life satisfaction, suicidality, and generally poor health. This supports clinical theories that recurrent nightmares are possible symptoms of mental and physical illness.

kitt price, a senior lecturer in modern and contemporary literature at Queen Mary University, London, described their historical and cultural analysis of the use in 19^th and 20^th century Britain of mass media to gather public reports of precognitive types of dreams. The BBC and other media outlets gathered thousands of such reports, many of which remain available for study today. price’s research suggests that interest in paranormal dreaming does not diminish in modern Western societies, but expresses itself through different kinds of media.

Alaya Dannu, an MFA student in creative nonfiction from the UK, discussed the ongoing influence via dreams of the beliefs and customs of civilizations that no longer exist (e.g., from pre-colonial Africa). She brought together art, anthropology, history, and her own personal experiences to illustrate the way dreaming helps to shape a personal and collective sense of identity over time.

Alison Dale and Joseph DeKonick, psychologists from the University of Ottawa, presented findings on gender differences in the dreams of Canadians that showed males have more dreams of aggression while females have more dreams with family and friend characters and more negative emotions. These findings fit with those from research on the dream patterns of other nationalities, adding strength to the idea that some tendencies of dreaming have roots in deep psychological processes shared by many if not all humans.

Don Kuiken, a psychologist from the University of Alberta, talked about his ongoing work on “impactful dreams,” focusing in this presentation on what he calls “existential” dreams of intense sadness, often following a loss or death of a loved one, which can paradoxically lead to “sublime disquietude” and greater aesthetic appreciation for life. Kuiken’s research has been an inspiration to me for many years, and this new development brings his impactful dreams work into dialogue with his earlier studies of dreams and the philosophical aesthetics of Samuel Taylor Coleridge.

Wojciech Owczaraski, from the University of Gdansk in Poland, described a project devoted to gathering dream reports from survivors of the Auschwitz concentration camp in WWII. This promises to be an important and heart-wrenching collection of dreams.

Caroline Horton and Josie Malinowski, psychologists at Bishop Grosseteste University and University of Bedfordshire, respectively, both in the UK, described their research testing the role of dreams in emotional assimilation. They found the strongest effects in dreams with greatest emotional intensity and personally important material. Researchers continue to debate the issue of how much of a role, if any, dreaming plays in memory, learning, and information processing. Several studies at the conference reported negligible results in experiments involving dreams and memory consolidation, and Horton and Malinowski’s project was the only one that found an angle of approach that might be promising.

Antti Revonsuo and Katja Valli, cognitive neuroscientists at the University of Turku in Finland, gave talks about their “social simulation theory” of dreaming, whereby dreams function to provide simulations of social situations that have relevance for evolutionary fitness and survival. This theory grew out of Revonsuo’s earlier studies of “threat simulation” in dreaming. The main advantage of Revonsuo and Valli’s current approach is that it builds on empirical research about dream content—quantitative data about the actual dreams of a large and wide variety of people. This kind of research has shown that dreams are filled with characters, social interactions, and verbal communications. These are the features of dreaming Revonsuo and Valli are trying to explain in terms of the evolutionary history of human cognitive functioning.

These are only some of the sessions I personally attended; there were many other great presentations I didn’t get to see but only heard about from other people.

The conference as a whole left several general impressions about the state of dream research.

First, new advances in various areas of investigation make it clear the mind’s activities in sleep are much more complex and sophisticated (“high-level”) than mainstream psychologists have long assumed. The numerous presentations on lucid dreaming and cognition during the sleep state support this deepening of our understanding of how the mind works (and plays) during sleep and dreaming.

Second, there has been tremendous growth in empirical data, but not as much progress in theoretical understanding. Researchers have more detailed dream material to look at than ever before, but they have very little to say that’s new about what dreams mean or how they function. My concern is that the real gains that have been made in describing the neurocognitive processes involved in dream formation are not improving our understanding of the role of dreaming in healthy human functioning. Very few researchers (Revonsuo and Valli being exceptions) try to locate their studies within a bigger theoretical framework. Perhaps this is simply the stage we’re at, following the demise of psychoanalysis and brainstem reductionism; we know that was wrong, but we’re still not sure what’s a better model. So in the meantime, we gather more data.

Third, and in tension with the second, the practical use of dreams in clinical and therapeutic contexts continues to expand and diversify. Professionals and laypeople involved in caregiving, whether in hospitals, school health centers, private therapy practices, hospice groups, churches, or non-governmental organizations, are using dreams as a valuable resource in helping people gain insights into their suffering and find their way back towards health and wholeness. Many conference presentations described the positive healing effects of bringing dreams into the therapeutic process, in almost every kind of clinical modality.

At some point the researchers and the clinicians are going to have to talk to each other…. perhaps with new technologies for studying dreams as the mediating link.

April 6, 2016September 12, 2020

Recent Interviews About “Big Dreams”

In the past couple of weeks I have spoken several times with journalists about Big Dreams: The Science of Dreaming and the Origins of Religion. It’s a daunting experience to have smart people read what you’ve written and ask sharp questions about how you put together your argument… and all the more intimidating with a tape recorder running. But I think the basic ideas from the book come through pretty well in these pieces. Continue reading “Recent Interviews About “Big Dreams””

February 13, 2016

Beyond the Eclipse of Research on Big Dreams

Solar_eclipse_1999_4_NR On Friday, February 19, I will visit with C.G. Jung Society of Atlanta and give a talk on “Big dreams: Religion, science, and Jung’s theory of highly memorable dreams,” followed by a workshop on Saturday titled “Dreaming as Theater of the Psyche.” I wrote the following essay for the Society newsletter as a prelude to the talk and workshop. Anyone who lives in the Atlanta area is welcome to join us!

“Big dreams,” as originally conceptualized by C.G. Jung, are rare, extremely vivid, and highly memorable dreams that people experience as being dramatically different from the relatively mundane and forgettable contents of “little dreams.” To appreciate the importance of this distinction between big and little dreams, one has to accept the basic premise that dreams in general have some degree of meaning. Unfortunately many psychologists in the years after Jung lost confidence in that premise, due to scientific developments that seemed to cast doubt on the whole enterprise of dream research. During the latter half of the 20^th century few investigators devoted much time or energy to studying the more unusual and intensified forms of oneiric experience Jung characterized as “big” dreams. Now, however, thanks to the 21^st century technological developments in cognitive science and data analysis, a better case can be made for the psychological significance and therapeutic value of dreaming in general, and highly memorable and impactful big dreams in particular. The time is ripe for a new approach to the kinds of dreams Jung referred to as the “richest jewels in the treasure-house of psychic experience.”

Jung’s mentor in the study of dreams, Sigmund Freud, was not especially interested in distinguishing between different types of dreams, big, little, or otherwise. Freud’s main goal was to illuminate the unconscious roots of a dream in the childhood wishes, fears, and fantasies of the dreamer. In his view the dream itself is irrelevant and can be ignored once the underlying wish has been identified. Indeed, because Freud’s theory posited that dreaming serves to protect sleep against disturbing eruptions from the unconscious, a big dream could be seen as a total failure of the basic function of dreaming. In his therapeutic work Freud did focus on strong emotions, unusual images, and character metamorphoses in his clients’ dream reports, all of which are frequent markers of big dreams, so he had some practical familiarity with the value of intensified dreaming. But he never took the next step of examining the distinctive qualities of these dreams and reflecting on what they mean for our psychological understanding of the human mind. That step was left for Freud’s erstwhile friend and follower, Jung.

Jung actually took two important steps that helped open the way for further investigation in this realm. In addition to naming the fundamental difference between average dreams and highly intensified big dreaming, Jung also recognized the importance of studying dreams in a series, across a period of time. He found in his clinical work that looking at a series of dreams, not just single dreams in isolation, enabled a better perspective on the psychological dynamics of the person’s life than could be gained from any one dream alone. Not only was this an invaluable insight for therapeutic purposes, but it also provided a way of clarifying the big dreams concept. To say precisely what makes a dream unusual and extraordinary, it helps to know what counts as the usual and ordinary patterns of dreaming. Studying a series of dreams can identify those general patterns so it becomes easier to determine with more specificity what makes big dreams so big.

Both Freud and Jung developed their ideas about dreams from the same sources of knowledge: their personal experiences, their clinical practices with mentally ill patients, their deep readings of classical philosophy and theology, and their early inklings of the significance of Darwinian evolution for theories of human nature. In therapeutic terms, Freudian and Jungian approaches to dream interpretation worked: they enabled clients to express emotionally important concerns and difficult feelings, and they gave therapists a new window into their clients’ unconscious conflicts. The practical value of including dreams in psychotherapy has never been seriously questioned by those with actual experience in the process, and recent works by Clara Hill and Milton Kramer show how vibrant this area of study remains.

However, as time went on mainstream psychologists found it increasingly difficult to support the theoretical claims of the early pioneers of dream study. Two blows in particular prompted great skepticism towards Freudian and Jungian approaches, leading to a general eclipse of interest in dreams of any type or variety through the better part of the 20^th century. The first blow was the discovery of two fundamentally different kinds of sleep, known as Rapid Eye Movement (REM) and Non-Rapid Eye Movement (NREM) sleep by American researchers, and referred to as Paradoxical Sleep (PS) and Slow Wave Sleep (SWS) by French researchers. Both sets of terms refer to regular cycles of variation in the levels of activation throughout the brain during an ordinary night’s sleep. Researchers soon found that dream recall was closely associated with the most intense phases of activation during the sleep cycle, which suggested that dreams were caused by automatic processes of the neural system in sleep (this isn’t actually true, but it seemed so for many years). These findings made it much harder to argue that a psychological approach could reach the “deepest” levels of a dream’s meaning, since neuroscience had apparently shown that the deepest cause of a dream is a purely physiological process in the brain during sleep.

The second blow came from systematic studies of dream content, like those of Calvin Hall and Robert Van de Castle starting in the 1950’s. These researchers accepted the idea that dreams contain some degree of psychological meaning, but they wanted to use quantitative methods to identify where those meanings might be found. The major discovery from this line of research was the simple continuity of dream content with waking life concerns. People tend to dream about the chief concerns of their regular daily lives. Most dreams, according to these findings, involve rather ordinary and mundane content: being in familiar places, with familiar people, doing familiar things. Contrary to their popular portrayal as bizarre and outlandish nonsense, dreams tend to portray fairly straightforward accounts of people’s feelings about their most important relationships, activities, and concerns in waking life.

The statistical research on dream content highlighted a genuine weakness in Freudian and Jungian dream theories, namely a narrow basis of evidence in terms of having access to broad, diverse sources of empirical evidence about dreaming. The research on REM sleep highlighted another weakness of Freudian and Jungian theories: losing connection with the best scientific understandings of the interaction between mind and brain, psyche and soma. Together, these two weaknesses undermined the credibility of Freud’s theory of dreams as wish-fulfillments aimed at protecting sleep and Jung’s theory of dreams as compensations for the excesses of consciousness. Neither theory could account for the neurological sources of dreams or for their mundane, generally trivial content. Jung’s interest in big dreams appeared especially questionable in this light, as it seemed to lead in exactly the opposite direction from where the best scientific evidence was pointing.

Throughout this time, clinicians and therapists kept doing their good and valuable work with dreams, but “eclectically,” with little theoretical guidance or grounding in empirical research. Few mental health professionals have received any training or instruction whatsoever in how to work with clients’ dreams. A few years ago when co-writing a book about dream education, Dreaming in the Classroom with Phil King and Bernard Welt, we were surprised and saddened to find so few schools of professional psychology offering any classes or course modules on the subject of dreams.

Several intrepid investigators have in recent years pursued detailed studies of the phenomenology of big dreams. Harry Hunt, Roger Knudson, Don Kuiken, Mark Solms, Tracey Kahan, Jayne Gackenbach, Ryan Hurd, and others have contributed to a better understanding of what Hunt called “the multiplicity of dreams,” but the overall tenor of 20^th century psychology took a decidedly negative turn toward the study of dreams, and therapists today are still paying the price.

Fortunately there are increasing signs of another major shift in dream research that bodes well for greater attention to big dreams in coming years. These signs of change emerge from the same two sources of scientific research that seemed so discouraging for the study of dreams in previous decades. The neuroscience of sleep has now advanced to a point of recognizing the truly remarkable complexity and sophistication of the brain’s activities during sleep. Far from a mental desert devoid of conscious activity, sleep in fact involves a wide variety of cognitive processes operating in ways that are different from, but not necessarily inferior to, those in the waking state. At various points during REM or Paradoxical Sleep, the brain’s overall electrical activation (as measured by EEG devices) equals or even exceeds the levels seen in the brain during waking. These and other findings make it clear that the sleeping brain is more than capable of generating the kinds of emotionally charged, visually intense, cognitively complex experiences that Jung characterized as big dreams.

Just as importantly, the systematic study of dream content has expanded to include more than just “most recent dreams” gathered from college students. Careful analysis of various kinds of dreams, including nightmares, lucid dreams, childhood dreams, death-related dreams, and other kinds of highly intensified dreaming, have shown that there are distinctive patterns of form and content that correlate to a remarkable degree with the latest neuroscientific findings about the brain’s activities during sleep. The ability to identify these kinds of correlations has been improved by database technologies that allow researchers to quickly and reliably analyze large collections of dream reports, compare their word usage frequencies with other collections of dreams, and highlight significant patterns of similarity and difference. The Dreambank (dreambank.net) website of G. William Domhoff and Adam Schneider, along with my Sleep and Dream Database (sleepanddreamdatabase.org), are two resources for exploring the use of these technologies and experimenting with different kinds of dreams and different applications.

Jung’s approach to the study of dream series can be deepened with these new tools for identifying recurrent patterns and tracking changes over time. This has exciting potentials not only for therapeutic practice but also for theoretical insight into the nature and functions of big dreams. The more we learn about the meaningful dimensions of a series of dreams, the better we will be able to appreciate the singular dream experiences that stand out from the ordinary flow of dreaming, the experiences that Jung felt were unique openings into the most profound reaches of the psyche. The brain-mind science of the 21^st century might finally be ready to verify Jung’s early insights about big dreams and develop them in creative new directions.

January 15, 2016February 25, 2024

Prophetic Rodents: Neuroscientists Find Hints That Rats Dream of the Future

imgres-1 New findings from brain researchers at University College London in the U.K. suggest that sleeping rats have the capacity to imagine a place they have never been in waking. This intriguing study does more than support the idea that many animals do indeed dream, in modes appropriate to the neural capacities and environmental experiences of their species. Beyond that, the study shows that rat dreams may have one of the key features of human dreaming, namely the ability to simulate future scenarios and prepare for anticipated efforts to achieve our goals.

Titled “Hippocampal place cells construct reward related sequences through unexplored space” and published in eLife on June 26, the researchers built on previous work showing the importance of the hippocampus in remembering places and forming mental maps of where we have been. The hippocampus is also important for imagination, forethought, and planning future goals. Crucially for this study, the hippocampus is active in waking and sleeping, and researchers have long known that the same hippocampal “place neurons” triggered into firing by a waking-life experience of a particular place will also fire during sleep. The challenge of this study was to find out if hippocampal neurons associated with a place will fire in sleep before any waking experience of the creature actually being in that place. In other words, will the sleeping brain anticipate a desired action? Will it dream of the future?

The experiment involved training rats (with electrodes implanted in their brains) to run through a maze where they could see, but not reach, another chamber where food was visibly located. The rats could also see but not reach an additional chamber with no food. During rest periods, the researchers recorded the rats’ hippocampal activity. Then the researchers let the rats run through the maze with no blockages, so they could reach the new chambers. It turned out the rats’ hippocampal activity when they first entered the new chamber with food was a close match with their hippocampal activity in sleep—the same place neurons that first fired in sleep later fired in waking life, too. The rats seemed to dream of going into that chamber before they actually did so.

The same effect was not found in relation to the chamber with no food. The preceding rest period did not include any hippocampal activity related to the rats’ later experiences in that place. This finding led the researchers to stress the significance of desire and intrinsic motivation in triggering this “preplay” effect.

The ultimate conclusion of the study was that “goal-biased preplay may support preparation for future experiences in novel environments.” These results give us a better understanding of how preplay, or imagination in a more general sense, can “simulate future experiences in environments yet to be actively explored,” in humans and in other species.

The limits of this research are considerable. Only four rats were used as participants; the periods of “rest” were not clearly sleep stages of any specific kind; and the published results depended on an extremely technical analysis that could allow for many hidden errors. These limits should add a note of caution when assessing the possible implications of the research.

That being said, the findings of this study have a clear affinity with theories of dream function that emphasize the values of the anticipatory simulations frequently occurring in dreaming experience. C.G. Jung spoke of “the prospective function” of dreams, Montague Ullman said dreaming worked to maintain an optimal state of “vigilance,” Frederick Snyder viewed sleep and dreaming as a “sentinel” system to prepare for environmental danger, Rosalind Cartwright argued that dreams serve as “rehearsals” for future actions, and Jeremy Taylor has focused on recurrent nightmares as warnings of psycho-spiritual danger in the dreamer’s waking life. Antti Revonsuo and Katja Valli have been developing the “Threat Simulation Theory” as a way of connecting typical patterns in dream content with brain functioning and the evolutionary challenges of our species. In my 2016 book Big Dreams: The Science of Dreaming and the Origins of Religion, I will talk at length about the capacity for creative forethought and visionary insight in dreaming.

All of which is to say, dream researchers from other areas have been working with similar ideas for years, and these new findings from the University College London team are a welcome addition to the accumulating evidence in favor of dreams having some kind of preparatory function that helps to orient the individual toward successful adaptation in the waking world.