“No cognitive state has been more extensively studied and is yet more misunderstood than dreaming,” writes Professor James F Pagel, a former director of the Sleep Disorders Center of Southern Colorado who has been involved in the study of sleep and dreams for more than 40 years; in which time he has authored numerous books on the subject, including Dream Science. 

Indeed, there is still a lack of complete understanding of why we dream. Nonetheless, the last few decades of research have revealed some pieces of the puzzle. 

Some experts suggest that dreams may offer an opportunity for creative problem-solving; others identify ways in which dreams may have a therapeutic effect; others still, point to dreams as a way to make sense of the past as well as anticipate future events. In the field of clinical psychology, some researchers have found a strong correlation between the kinds of dreams we have and our mental wellbeing. And outside of the laboratory and the halls of academia, in cultures around the world, dreams take on a spiritual significance. Locally, sangomas generally report receiving their calling from ancestors through dreams, and even receiving instructions and knowledge about which medicinal plants to use through dreams. 

We take a closer look at research that reveals how dreams can help us solve problems, as well as strengthen our memory.

Creative problem-solving through dreams

Inspired by previous research, as well as anecdotes of historical figures, including scientists and artists who claimed certain discoveries and solutions had come to them through dreams, Harvard lecturer, author and former president of the International Association for the Study of Dreams, Deirdre Barrett, conducted a study in 1993, to test the possibility of problem-solving while dreaming.

She asked some 76 college students to “incubate dreams” that would address specific questions and problems that they were dealing with in their daily lives. Barrett describes dream incubation as a technique that involves directing the content of one’s dreams through bedtime self-suggestions.

In an article she wrote for Scientific American, published in 2020, she summarises the technique in five steps: 

1. Write down the problem as a brief phrase on a notepad and place the notepad by the bed. You can also arrange related objects where you can see them from the bed.
2. Review the problem for a few minutes just before bedtime.
3. Once in bed, visualise the problem as a concrete image if possible.
4. As you drift off to sleep, tell yourself you want to dream about the problem. Visualise yourself dreaming about the problem, awakening, and writing on the notepad.
5. Upon awakening, lie quietly in bed and note whether there is any trace of a recalled dream, inviting more of the dream to return if possible. Write it down.

For her 1993 study, the subjects followed the technique every night for a week, or until they had a dream they felt solved their problem, recording all the dreams they remembered throughout the study. In addition to the participants’ own perception of whether their dreams had solved their problems, she also had two research assistants function as independent judges, to ascertain whether or not their self-reported dreams qualified as solutions to their problems.

The participants chose a range of issues across personal, medical and academic issues. Fifty-one percent of them managed to dream about the specific topic, and 25% of them actually came to a solution in their dreams that could also be validated by independent judges. Barrett conducted more research and experiments on dream-state problem solving, and in 2001, published a book called The Committee of Sleep: How Artists, Scientists, and Athletes Use Their Dreams for Creative Problem Solving — And How You Can Too, where she interviews several professionals and goes deeper into the dream incubation technique for problem-solving.

“Dreams were particularly good for finding solutions that required thinking outside the box. This makes sense with regard to what we know about the physiology of REM sleep: the prefrontal cortex is damped down so that we are not as quick to censor with ‘That’s not the way to approach it.’ Dreams are also especially useful when solutions can be visualized, and the secondary visual cortex — associated with imagery — is more active during REM,” she wrote of her findings. 

However, she clarifies that in her view, problem-solving in a dream state is not a magical technique that connects us to some wiser fantastical self that knows all, but rather another mode of thinking that can be drawn upon to supplement thought processes in our awake state. 

In a 2017 article for the Annals of the New York Academy of Sciences, she wrote of her research: “Some dream workers glamorize dreaming as wiser than waking thought; that is not what this research suggests. If humans had to get along with only one mode of thought, waking would obviously be the preferable one. However, the power of dream thinking lies in how different it is from what the waking mind does — so when we are stuck on a problem, dreams can supply the breakthrough.”

Dreams strengthen memories and give a peek into possible futures

A more recent study, authored by cognitive neuroscientist Erin J Wamsley, and published in March 2022, took a closer look at the way dreams draw on past memories to simulate future scenarios. Based on the wide body of research on the benefits of sleep, which has resulted in findings that “sleep not only quantitatively strengthens memory, but also qualitatively transforms past memory traces in a way that may help us respond to similar events in the future”, Wamsley sought to investigate the role dreams, in particular, play in that process.

“Emerging evidence suggests that dreaming is related to these putative memory functions of sleep. First, while dreams are rarely an exact replication of any particular past experience, they very often incorporate isolated elements drawn from recent episodic memories… Experiences that take up a large amount of our time, such as reading or working on a computer, appear in dreams less often than shorter-duration but potentially more meaningful categories of events, including social interactions and experiences rated as being significant, novel, or concerning… 

“Importantly, when recent experiences appear in dreams, even in fragmentary form, subsequent memory for those experiences is improved. Across a number of recent studies, it has been demonstrated that after completing a laboratory-introduced learning task, participants who report task-related dreams show greater improvements in performance after sleep, relative to participants who do not dream about the learning task,” she writes.

As part of her study, she found that just over a quarter of participants had dreams that related to impending future events. These were not necessarily realistic simulations, but rather an intermingling of elements drawn from multiple past events and imagined future scenarios. Even among those dreamers who reported no simulations of future events, their dreams still combined multiple past memories. 

“Co-activation of multiple past memories may itself serve a memory processing function. When a recent episode from the previous day is co-activated with related remote or semantic memories, synaptic connections between the recent memory and its neocortical associates may be strengthened, supporting the gradual integration of new information with existing knowledge structures. Indeed, a handful of studies suggest that sleep facilitates memory integration,” she explains.

Virtual reality: dreams as the original metaverse

As for those minority of cases that dreamt up future scenarios, Wamsley writes that this could potentially reflect another function for dreaming, “in which past memory stores serve as the raw material for rehearsing possible futures”. Other studies she quotes propose that: “Dreaming specifically evolved as an adaptive system for simulating dangerous events, allowing our ancestors to enhance their preparedness for future life-threatening situations through offline mental rehearsal in a realistic virtual environment.”

However, due to the “often highly unrealistic” nature of dream scenarios, Wamsley posits that simulations of future events in dreams are more likely to be a reflection of functional brain processes, such as an ongoing reactivation and consolidation of memories that might be relevant to anticipated future events. 

Still, she concludes that “prospective dreams may be an emergent phenomenon occurring when various fragments of future-relevant episodic and semantic memory are co-activated and combined in novel ways. The result is a dream that participants perceive to be ‘about the future’. Despite the fact that such dreams are often bizarre and unrealistic, this offline reactivation of future-relevant past memory could potentially function to help prepare us for the future.” DM/ML

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