Dreams have always been an interesting and fascinating topic, which still intrigues scientists to this day. Therefore, it is not surprising that there are still numerous studies trying to find answers to the question of how and why we dream, because more and more evidence links dreaming to health.
“What a strange and wonderful experience it is that we are thrown into these virtual worlds where we meet people, communicate with them, where we can feel all kinds of emotions,” said Prof. Antonio Zadra, researcher of sleep and dreams from the University of Montreal, in a recent interview.
In the late 19th century, scientists began to examine the neurological basis of dreams. In 1893, psychologist Mary Calkins conducted a study with two subjects – one man and one woman – who slept by candlelight, and she woke them up during the night and asked them if they had dreamed anything and to describe the vividness of their dreams to her.
From Calkins to Freud
Calkins was the first to quantify the elements and time in dreams. She found that dreams generally take place in the present, and “when the dream was about a childhood home, or about a person not seen for many years, the apparent age of the dreamer was never reduced to avoid anachronism… So it is obvious that the dream is connected to waking life, and usually to recent life.”
But shortly after her work, interest shifted to what dreams mean, notes Prof. Zadar, at least partly because of Sigmund Freud.
Starting in 1900, the founder of psychoanalysis presented dreaming in the context of repressed desires. Freud, for example, wrote that some anxiety dreams stem “from psychosexual excitation, in which case anxiety corresponds to a repressed libido.” And, if one dreamed that a still-living family member was dying, Freud believed that “the dreamer wished that they had died at some point during their childhood.”
Interest returned with the discovery of REM sleep in 1953 and the subsequent observation that when people wake up from REM sleep, they can often describe their dreams very vividly. Research has since shown that dreaming can occur during many stages of sleep. Even people who have brain lesions or take drugs that eliminate REM sleep still dream.
Although certain patterns of electrical activity in the brain are associated with the presence or absence of dreaming, there is still no definitive biomarker that signals whether a person is dreaming. Over the past decade, increased attention has been paid to the default mode network—a group of brain regions that become active when one’s mind wanders, for example, while looking out the window.
“Many recent models of why we dream are related to dreams as an enhanced form of mind wandering,” states Zadra. But why we dream is still a point of contention among researchers.
One of the longest-standing hypotheses is that dreaming serves as a means of simulating potential threats, preparing us for dangers that may befall us.
“But many, many dreams have no physical or psychological threats,” notes Zadra. He posits that we dream in order to make sense of our waking experiences in the context of our past, drawing in loosely connected connections—something that the default mode network allows us to do.
“When you wake up, things are integrated into your understanding of yourself, the world, your place in it, in bizarre, disjointed ways,” he adds. “And what does that help you? It helps you anticipate, or rather adapt to, what’s ahead.”
Processing emotions
Another leading explanation is that dreams help us process and regulate our emotions.
Sarah Mednick, a neuroscientist at the University of California, Irvine, says she sees dreams as “a safe space where we can bring out potentially emotionally charged experiences” and then take advantage of the possibilities. “What we see is an increase in arousal during dreams, but then you also see a decrease in that arousal during sleep.”
In her research, Mednikova discovered that for people who have experienced a negative emotional event, dreaming about it can help suppress related emotions, according to RTS.
“If you dream about an event, you will retain a detailed memory of the event, but you will also, over time, have less emotional arousal when you think about the event,” explains Mednikova.
He also sees dreams as a kind of “overnight therapy,” citing a sleep study that found that among divorced people, those who dreamed of their ex-spouses had fewer symptoms of depression after a year. This illustrates that dreaming can have “beautiful long-term implications for a healthy relationship with your emotional past,” Mednikova points out.
Insights from dreams
But many of us don’t remember our dreams. In sleep studies where participants woke up every five minutes during the night, most reported having dozens of dreams, meaning a person who wakes up briefly during the night might remember more of their dreams.
Interest in a dream can also affect whether you remember it, Zadra said, as can waking up without an alarm.
“If you wake up naturally, there’s a higher chance you’ll wake up from REM sleep,” said Ying Zhang, a neurologist at Harvard Medical School and Massachusetts General Hospital. Waking up during REM increases your chances of being in the middle of your sleep. Zhang suggested writing down the dreams you remember as soon as you wake up, as studies show that doing so improves dream recall.
Dreams can provide insight into one’s quality of life
People who are under more stress or anxiety “have more negative dreams and more negative dream content,” Zadra points out. “They have more aggressive dream interactions than friendly ones. They have more hostilities, they have more failures than successes. But as a person’s quality of life improves, there are corresponding changes in the content of their dreams.”
“Many with mood disorders — depression, anxiety, post-traumatic stress — report different patterns of dreaming, and a large number of dreams,” which may be the result of prolonged REM sleep, according to Zhang, who researches the role of dreaming in psychiatric populations, particularly people with schizophrenia.
If someone with post-traumatic syndrome experiences recurring nightmares, “they have a worse prognosis in terms of symptoms. It is an indication that the system is not adapting as it should,” Zadra points out. But this can be reframed as an opportunity for someone to ask for help. “They need therapy, they need medicine, they need something,” emphasized Prof. Antonio Zadar.