In her new paper, Erin Wamsley shows that while most dreams are made of elements of past experiences, many dreams (25 percent in her study), are made of experiences traced to “anticipated future events.”
She asked her study participants to spend a night at a sleep lab, where her team repeatedly awoke participants at different times during the night. When awakened, participants were asked to report their dreams. In the morning, participants were invited to listen to audio recordings of their own nocturnal dreams and to identify dream sources, ie, to tell researchers where specific dream elements come from (with memories, dated).
In addition to identifying a memory source from the past, Wamsley asked her participants to also provide information about memory sources from the anticipated future events. As expected, most dreams could be traced to a memory source from sometime in the past, but in addition, about a quarter of all collected dreams contained references to imagined future events (such as the impending performance of the participant’s band, or anticipation of planned moving). Lastly, many dreams contained both past sources and anticipatory future sources.
These results are exciting for understanding dreaming and its functions, but also for understanding how we experience time more generally. Our minds construct our pasts and imagine futures, and this happens across states of consciousness and wake-sleep boundaries.
Dreams Are Made of Memories
Sleep serves many vital functions, ranging from basic physiological mechanisms to complex cognitive processes. When facing new problems, challenges and anxieties, we say “sleep on it”. This idea is taken quite literally by the domain of sleep research, with ample evidence showing that something special happens in our brains during sleep, some processes that allow our minds to consolidate memories, make sense of our lives, and be ready in the morning to Tackle our the new day with fresh perspectives.
So what about dreaming? Does dream content matter in this largely unconscious process of memory consolidation in sleep? Understanding the functions of dreams is a kind of a holy grail for dream researchers. We obsess and fight over the ideas of why dreams are important, what is their function (if any!), and if dreaming of something that happened to us helps or hinders the consolidation of memories.
Dreams’ role in memory is still an open question, with studies showing that dreams incorporate memories but almost never replay them, that memory sources of dreams may come from the day before (a phenomenon that Freud called the day residue), sometimes from five to seven days earlier (what dream researcher Tore Nielsen calls the dream-lag), and sometimes from distant past. Researchers also report that we dream about what we care about–in addition to seemingly random elements from our lives, people, places, events, and even concepts and ideas that are important to us often make it into our dreams.
Do dreams help consolidate memories? In other words, if you learn something today, would it be good for your memory if you dream about it tonight? Many studies have tried to answer this question, with some finding evidence for memory improvement after dreaming of an experimental task, and others failing to find any such relationship.
Clearly, if dreams have a relationship with memory, it is not quite as simple as dreaming of something that must be remembered. After all, people who claim to almost never remember their dreams do not seem to have obvious cognitive deficits compared to those who dream a lot! Dreams may be made of memories but perhaps dreams are not for memory, at least, not exclusively.
Memories and Dreams Are Constructive, Dynamic, and Creative
The role of sleep in memory, even if not completely understood, is rather accepted by the scientific community. But what is memory? We now know that personal or autobiographic memory is not an archive in which we conserve events and emotions that we can retrieve and use when needed. Instead, many scientists believe that memories are dynamic, that they change over time, and that an act of remembering could essentially be an act of constructing or creating that memory anew.
When you think of your past under different circumstances, you can remember the same event as the best thing that ever happened to you, or as the worst decision of your life. And that re-remembering will make a lasting impact on the original memory, which may eventually become largely fictitious. As they say, “it’s never too late to have a happy childhood”.
But is it also never too late to have a happy future? A memory scientist, Daniel Schacter, proposed that our ability to constructively remember the past underlies our ability to creatively imagine the future.
Dreams Are Made of Imagining Futures
Now, back to the future. Imagining futures requires cognitive flexibility, an ability to make plans, and to think of something that has not happened yet. We make use of memories to predict what the future may look like, but we also know that the future is basically unknowable, which can be quite unsettling.
Many theories propose that dreams are creating virtual spaces, a “simulation” of the world (worlds?) where we can rehearse different scenarios. Would those rehearsals improve our fitness in our evolutionary niche? Maybe. Or perhaps those are imaginative, playful spaces where we don’t just prepare for the “real” world, but where we can be allowed to live other kinds of experiences.
As dream scientist Kelly Bulkeley suggested, dreams can be seen as a form of play that enhances our cognitive flexibility and allows us to tackle life creatively.
Dreaming up new scenarios and narratives, mixing and matching past experiences (sometimes even with memories of past dreams!), and combining elements of the past with elements of the anticipated future is, perhaps, an important way in which our minds help us deal with uncertainty and anchor us, however fictionally, in the present moment while extending our selves into the past and projecting into the future.