“Why do some of us never remember our dreams?”, Vinh Hung Loi asks us on our Facebook page. This is our reader question of the week. Thank you all for your participation.
While dreams have intrigued humans since the dawn of time, it was only in the mid-20th century that neuroscientific clues began to emerge to explain why some of us wake up with a vivid memory of our dreams in our heads, while others forget them completely.
Dreams, much more than a nocturnal distraction
But why do we dream? According to Matthew Walker, a neurologist at the University of California at Berkeley (United States), dreams play a role a central role in mental health. It would serve to regulate emotions, allowing to relive events without the associated anxiety and to prepare to face similar situations in real life. In addition, dreams would promote problem solving and stimulate creativity. This hypothesis establishes the dream as an essential mechanism for psychological well-being.
However, while everyone dreams (see the box below), some do not remember their contents. To understand why, we must explore how sleep works.
Taking control of your dreams is possible!
About half of us have had an astonishing experience: living a dream consciously, knowing that we are asleep and managing to influence the dream scenario. An intriguing phenomenon, known since antiquity, but which researchers have only recently started to study. They have even managed to develop a "recipe" to become a lucid dreamer. To discover it, go to your newsagents to get you the number 933 (November 2024) from Science and Future !
“Taking control of your dreams”: the cover of the monthly Sciences et Avenir ndeg933.
No, we don't only dream during REM sleep!
Every night, our sleep is made up of several cycles, each comprising different phases, including slow-wave sleep and REM sleep. Contrary to popular belief, REM sleep is not the only phase where we dream.
The work carried out in the 1960s by Michel Jouvet, a pioneer in the study of sleep, have contributed to this misperception. In reality, it is entirely possible to dream during slow-wave sleep, although the stories are generally less vivid and less graphic than those from REM sleep.
Read also"The dream is a draft of reality"
REM sleep phases are longest at the end of the night, which explains why we remember dreams that occur at this time more easily. However, waking up briefly during the night is often crucial for the brain to "encode" the dream and make it accessible to waking memory.
The importance of night awakenings to remember your dream
Perrine Ruby, a researcher at the Lyon Neuroscience Research Center, has closely studied the correlation between night awakenings and dream memoryHis work shows that people who wake up several times during the night remember their dreams more often.
For the brain to register the dream, an awakening of at least two minutes seems necessary. These awakenings can be so brief that we do not remember them, but they are enough for the dream experience to be engraved in the memory.
Brains that don't record dreams?
Although nearly 20% of the population claims to never dream, more in-depth studies, such as those conducted by the American neurologist James Pagel, reveal that true non-dreamers represent less than 1 % of the population. These people have no particular pathology and possess the ability to generate mental images. Scientists believe that their brains simply do not store the memories of their dreams. Why this phenomenon occurs, however, remains a mystery.
Remembering your dreams, a question of physiology and… experience
The difference in dream recall could therefore be attributed to the way in which individuals wake up. Those who have more fragmented sleep, interspersed with even brief awakenings, are more likely to recall their dreams. This process implies that sleep quality, the duration of REM sleep phases and the presence of nocturnal awakenings all play a role.
Read also“Dreams are fascinating: they concern everyone and we know so little about them…”
Individual differences in dream memory are thus explained by a complex interplay between sleep habits, physiology and neurological characteristics specific to each individual. So the next time you wake up with a fascinating dream memory or feel like you didn't dream at all, you'll know that subtle mechanisms are at work, testifying to the complexity of sleep and human memory.
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