According to new research in the journal Nature and Science of Sleep, people who can recall their dreams often have increased ability to craft and function connectivity in a key brain network. These findings give new insights into the neurophysiological implications of dreaming.
Depending on your intention, dreaming is one of the last frontiers of human cognition a terra incognita of the mind, according to 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 that are unanswered, which is evidently a very interesting topic to study!
One of these key research questions is addressed in this and previous research: why do some individuals recall their dreams every day, while others almost never seem to recall a dream?
For his latest study, Vallat and his colleagues used brain imaging techniques to determine if neurophysiological differences exist between individuals who often recall their dreams and those who do not.
The study included 55 healthy participants 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 Le Vinatier Hospital the night before their scanning session and completed self-reported assessments of personality, anxiety, and sleep quality. They completed the Wechsler Memory Scale (used to measure immediate and delayed memory performance), the Guildford Uses Task (used to measure creative capacity) and a digit span task (used to measure working memorys). After staying at the lab overnight, participants underwent three functional magnetic resonance imaging scans to evaluate resting-state brain activity.
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, indicating that they had more creative abilities.
According to Vallat, enhanced functional connectivity in high-visibility recallers in the default mode network would be beneficial during day-dreaming and mind-wandering. In addition, increased connectivity between the medial prefrontal cortex and the temporo-parietal junction was specifically suggested to stimulate creativity and dreaming.
According to Vallat, high dream recallers have excellent creative abilities as well as a different brain function, as demonstrated by this research and previous reports from our lab. It remains to be seen if there is a causal connection 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, or does an innate higher functional connectivity of the default mode network in these individuals enhance their dream recall and creative capabilities?
The following steps of this study might be to take a group of non-dreamers, increase their dream recall abilities over time by using some powerful 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). Furthermore, Vallat explained, he will evaluate their creativity and brain function before and after the manipulation.
Like all functional magnetic resonance imaging (fMRI) studies, we have used a fairly small sample size, which can be very generalizable (i.e. do these findings hold for a larger and more diverse population?) Vallat said.
In this study, participants are given two minutes to list as many alternative uses as possible for an everyday object. 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 identified a single subdomain of creativity.
This is why Vallat said that studying dreams is a nightmare (sorry for the pun) because it is not directly observable: If the sleeper does not show any dreams, we must therefore rely on them to see if they were not dreaming or were in fact dreaming upon waking.
Raphael Vallat, Basak Turker, Alain Nicolas, and Perrine Ruby, both author of the study, High Dream Recall Frequency, is linked to increased creativity and Default Mode network connectivity.