People who can frequently recall their dreams tend to be more creative and exhibit increased functional connectivity in a key brain network, according to new research published in the journal Nature and Science of Sleep. The findings provide new insights into the neurophysiological correlates of dreaming.
“I think that dreaming is one of the last frontiers of human cognition — a terra incognita of the mind if you will,” said study author Raphael Vallat, a postdoctoral researcher at the Center for Human Sleep Science at the University of California, Berkeley. “Although we all spend a significant amount of our lives dreaming, there are still so many basic research questions related to dreams that are unanswered, which obviously makes it such a fascinating topic to study!
“In this and previous studies, we address one of these fundamental research questions: why do some people recall their dreams every day while others almost never seem to recall a dream?”
For his new study, Vallat and his colleagues used brain imaging techniques to examine whether neurophysiological differences exist between individuals who frequently recall their dreams and those who do not.
The study included 55 healthy participants (ages 19–29) with normal sleep characteristics and body mass index. Twenty-eight participants were high dream recallers (able to recall about 6 dreams per week on average), while 27 participants were low dream recallers (recalling less than one dream per week on average). The two groups did not significantly differ in age, habitual sleep duration, or education.
Participants arrived at the sleep lab at Le Vinatier Hospital the night before their scanning session and completed self-reported assessments of personality, anxiety, and sleep quality. They also completed the Wechsler Memory Scale (used to measure immediate and delayed memory performance), the Guildford Uses Task (used to measure creative ability), and a digit span task (used to measure working memory’s number storage capacity). After staying at the lab overnight, the participants underwent three functional magnetic resonance imaging scans to measure resting-state brain activity.
The researchers found that high dream recallers and low dream recallers had similar personalities, levels of anxiety, sleep quality, and memory abilities. However, high dream recallers scored significantly higher on the Guildford Uses Task than low dream recallers, indicating that they had greater creative abilities.
Vallat and his colleagues also observed increased functional connectivity within the default mode network in high dream recallers compared to low dream recallers. The brain network “is known to be active during day-dreaming, mind-wandering (e.g. getting lost in your thoughts), and has been further suggested to promote creativity and dreaming,” Vallat explained. The increased connectivity was specifically found between the medial prefrontal cortex and the temporo-parietal junction, in line with clinical reports that have shown lesions to these brain regions result in a cessation of dream recall.
“In simpler words, high dream recallers have superior creative abilities, as well as a different brain functional organization, as demonstrated by this study and previous studies from our lab,” Vallat told PsyPost. “It remains an open question whether there is a causal relationship between dream recall, creative thinking, and brain ‘wiring’, and if so, what is the direction of that relationship (the chicken or egg problem). Does increased dreaming promote creative thinking and ultimately lead to changes in brain function? Or does an innate higher functional connectivity of the default mode network in these individuals promote their dream recall and creative abilities?”
An experimental methodology could help to untangle the causal relationships. “A next step of this study could be to take a group of non-dreamers, increase their dream recall abilities over time using some validated methods (the most known of which is to simply write down their dreams every morning as they wake up, the conscious effort of remembering their dreams eventually leading to a better recall of dreams), and assess their creativity and brain function before and after the manipulation,” Vallat explained.
But the study, like all research, includes some limitations. “Like most functional magnetic resonance imaging (fMRI) studies, we have used a fairly small sample size, which limits the generalizability of our findings (i.e. do these findings hold for a larger and more diverse population?),” Vallat said.
The study also only examined one type of creativity. In the Guildford Uses Task, participants are given two minutes to list as many alternative uses as possible for an everyday object. The total number of responses and the number of rare uses are used to measure a type of creative ability known as divergent thinking. “Creativity is an umbrella term that encompasses several concepts (e.g. convergent vs divergent thinking, problem solving, gist extraction, etc). In this study, we have measured a single subdomain of creativity,” Vallat noted.
“Understanding differences in dream recall between individuals is just one angle through which we are trying to decipher this fascinating and mysterious phenomenon that is dreaming,” Vallat said. “Studying dreams is a nightmare (sorry for the pun!) because it is not directly observable: we do not know exactly when dreaming happens during sleep, and we must therefore rely on waking up the sleeper to ask whether they were dreaming or not prior to awakening. Even then, this is imperfect because if they do not report any dreams, we cannot know for sure whether they were not dreaming or were in fact dreaming but immediately forgot their dream(s) upon waking.”
The study, “High Dream Recall Frequency is Associated with Increased Creativity and Default Mode Network Connectivity“, was authored by Raphael Vallat, Başak Türker, Alain Nicolas, and Perrine Ruby.