While we sleep, our brain goes through different cycles and phases, each with a different function. One of these phases is called REM sleep (for “rapid eye movements”), and since it was discovered in the fifties, it has been the most studied phase of sleep. In fact, its crucial functions for our body and our brain, such as brain maturation and memory consolidation, have interested sleep scientists for decades. If this sounds all new to you, we recommend that you read our first article about the subject:
As you might already know, REM sleep is the stage where most dreams happen, and these two elements go together. Actually, many studies failed to separate the physical phenomenon, the sleep phase, from the psychological one, dreams. That demonstrates that REM sleep and dreams functions are related.
REM sleep is where we consolidate positive and negative emotional memories, more than neutral ones. This is actually made during REM sleep, through dreams. In this process, dreams are a “replay” of waking-life emotional events where we dream of what we lived; in fact, brain regions of emotional encoding and consolidation have a strong relationship with dream contents.
But during dreams we don’t only consolidate our memories, we reorganize them. That’s the reason why, in dreams, we experience weird associations between elements of our waking life not really related to each other. This is why, for example, if you had lunch at your grandmother’s and then you played Mario Kart all afternoon, it wouldn’t be so weird to dream of your grandma in a kart racing.
This replay and reorganization is crucial, actually we wouldn’t be able to completely consolidate memories if we get deprived of REM stage of sleep and dreams.
Memory is not the only function of dreams. Related to emotions, in dreams we experience negative emotions (such as fear and anxiety) twice as much as positive ones. Sad, isn’t it? But this masochism has a central function. An important theory says that dreams could represent a sort of simulation of reality, especially of two specific situations.
The first are dangerous situations and threats. Apparently, this mechanism would go back to the stone age when the possibility to “train” to escape from danger in dreams would have been an evolutionary advantage for survival for our ancestors.
Of course, today we don’t dream of running from saber-toothed tigers anymore. Instead, we dream of more contemporary dangerous situations like car accidents, in order to be more careful in daily life.
The second kind of simulation would be of social situations, positive and negative. Dreaming of people and situations gives the possibility to create new scenarios of the future and it’s a form of rehearsal for waking social interactions.
The fact that dreams incorporate daily events to simulate reality helps us train our problem-solving based on emotional coping strategies even if we don’t always remember it. This way we can face social and emotional situations in waking life.
Who would have said that these nightly weird products of our brain could have such important purposes? And this is what they do without us being aware of it, but dreams have a lot of other potentials if you know how to exploit them. We tell you all about that in our articles, starting from :
Domhoff, G. W., & Schneider, A. (2018). Are dreams social simulations? Or are they enactments of conceptions and personal concerns? An empirical and theoretical comparison of two dream theories. Dreaming, 28 (1), 1.
(French) Jacquemont, G. (2020). La science des rêves: S’en souvenir – Les interpréter – Les piloter. Paris: Flammarion.
Oudiette, D., Dealberto, M. J., Uguccioni, G., Golmard, J. L., Merino-Andreu, M., Tafti, M., … & Arnulf, I. (2012). Dreaming without REM sleep. Consciousness and cognition, 21(3), 1129-1140.
Revonsuo, A. (2000). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23 (6), 877-901.
Scarpelli, S., Bartolacci, C., D’Atri, A., Gorgoni, M., & De Gennaro, L. (2019). The functional role of dreaming in emotional processes. Frontiers in psychology, 10, 459.
Vallat, R., Chatard, B., Blagrove, M., & Ruby, P. (2017). Characteristics of the memory sources of dreams: A new version of the content-matching paradigm to take mundane and remote memories into account. PLoS One, 12 (10), e0185262.
Walker, M. (2017). Why we sleep: the new science of sleep and dreams. Penguin UK.