Why We Evolved to Dream at Night and What Dreams Mean

By Leslie Alan Horvitz

Last of three parts

It also seems that bad dreams, which may be related to emotional problems in waking life, are recalled more frequently and accurately than those relatively free from anxiety and worry. One study of college students examined whether dream recall and dream content would reflect the social relationships of the person dreaming. The student volunteers were assessed on multiple psychological factors, such as attachment, recall, and dream content.

Those who rated high on “insecure attachment” were more likely to report intense images in their dreams and that they were more emotionally charged. Participants rated as “preoccupied” were also more likely to remember their dreams than those assessed as “avoidant,” who ranked lowest in dream recall. That suggests that those participants who were coping with more emotional problems in their waking life were also more likely to remember their dreams, which, in the cases of the insecurely attached and preoccupied, were likely to be more intense.

No Dreams at All?

A minority of people don’t have any dreams (unlike those who never recall them). These people have a rare condition called Charcot-Wilbrand syndrome, which occurs as a result of focal brain damage (typically a stroke) that impairs the brain’s capacity to process visual information or “revisualize” images. According to neurologist Macdonald Critchley, in Charcot-Willard, “a patient loses the power to conjure up visual images or memories and ceases to dream during his sleeping hours.” In 2004, a 74-year-old woman with a blockage of her occipital artery, which is involved in transmitting visual imagery to the occipital lobe of the brain, ceased to have any dreams over three months.

Neuroscience of Dreams

Neuroimaging studies of brain activity during REM sleep have led scientists to believe that brain activity might be linked to specific dream features. They have focused on the paleocortical and subcortical limbic areas, which are active in the dream state. One 2014 study has linked frontotemporal gamma EEG activity to conscious awareness in dreams. The study found that electrical stimulation in the lower gamma band during REM sleep influences brain activity and may even induce self-reflective awareness in dreams.

Several bizarre features of dreams, such as delusional misidentifications of faces and places, have similarities with well-known neuropsychological syndromes that occur after brain damage.

The right and left hemispheres of the brain contribute in different ways to dream formation. One study concluded that dreams seem to originate in the left hemisphere, while the right contributes to the dream’s vividness, figurativeness, and affective activation. It’s as if one control mechanism tunes in the station while the other brings the broadcast into focus and adds color.

Dream recollection and intensity change over time. Dreams are affected by how a person experiences changes in sleep timing, structure, and electroencephalographic (EEG) activity.

Pain and Dreams

Pain is a complex phenomenon. Whether it exists independently or is a result of perception (such as what occurs with pain from phantom limbs), the pain is real for the person who experiences it. Self-reporting may be the only way that pain can be determined. There has yet to be any quantifiable way to assess the degree of pain. Studies have shown that realistic, localized painful sensations can be experienced in dreams, either through direct incorporation (the pain is felt because it originates from or occurs during the dream) or indirect incorporation in that it comes from memories of pain. Researchers have yet to establish a mechanism to explain the relationship between pain and bad dreams. Still, bad dreams generally occur during REM sleep, suggesting that pain experiences alter the dream content or that the amount of REM sleep is altered by the physiological effects of pain on the brain.

However, the frequency of pain dreams, even in subjects who have pain, isn’t as great as you might think. A study of 28 unventilated burn victims within days of their admission for their injuries showed that 39 percent reported dreams that involved pain and that 30 percent of their total dreams were pain-related. This group experienced reduced sleep, had more nightmares, and required a greater dosage of anti-anxiety drugs. They also tended to report more intense pain during therapeutic procedures. However, more than half of the burn victims in this study did not report pain dreams more than regular volunteers who were part of the control group.

Although researchers haven’t established a strong independent correlation between pain and pain in bad dreams, they believe a connection exists. Migraines, for example, may be associated with bad dreams. The reverse may also be true; bad dreams may occur during an ongoing migraine episode, or they may precede the onset of the most painful part of a migraine.

Studies on people with migraines also found that they reported dreams involving taste and smell more than people who didn’t suffer from migraines. This finding may suggest that specific cerebral structures, such as the amygdala and hypothalamus, may play a more significant role in producing migraines than neuroscientists have previously suspected.

Death in dreams

To study dreams about death, researchers chose a group that was preoccupied with death: those who had been admitted into a psychiatric facility after attempting to take their own lives. Those who had considered or attempted suicide or carried out violence were more likely to have dreams with content relating to death and destructive violence. Depressives had more dreams about death.

But for those who were in a hospital because they were very ill and fighting cancer, the results of dream studies were different. Neuroscientist Jandial, treating patients at City of Hope Cancer Center in Los Angeles, observed a phenomenon he terms “dreams to the rescue.” For some patients near the end of their lives, “even though the day is filled with struggle, the dreams are of reconciliation, of hope, of positive emotions. I was surprised to find that end-of-life dreams are a common thing, and they lean positive.”

Jandial found evidence that death may come with one final dream. “Once the heart stops, with the last gush of blood up the carotid [artery] to the brain, the brain’s electricity explodes in the minute or two after cardiac death… Those patterns look like expansive electrical brainwave patterns of dreaming and memory recall.”

Romantic Relationships and Dreams

Researchers have revealed a link between romantic attachment and the content of people’s dreams. One of these studies, conducted on 61 students who were in committed relationships for six months or longer, revealed a significant association. Asking participants to think about certain people before sleep increased the likelihood of the participant reporting dreaming about that person. If researchers asked the participant not to think about a particular person, it only increased dreams about them. The results were stronger when participants were asked to focus on a person they found romantically attractive (versus a person they were not attracted to).

The researchers relied on what is known as a secure base script. Attachment begins in childhood when parents are often the central attachment figures. Securely attached people rely on the secure base script, which includes three components: recognizing and displaying distress, seeking proximity to attachment figures, and problem-solving. Those with secure attachments have learned to expect support from others during distress and understand that their actions can reduce distress. In contrast, insecurely attached individuals often show avoidance as a defensive strategy in that it protects them from physical harm—should they display anger toward the attachment figure—and emotional harm—should their bids for attention be ignored yet again. Avoidant people may attempt to reject any information that could cause anxiety and activate the attachment system. These attachment behaviors are often unconscious, but they emerge in dreams. Those with an insecure attachment are more likely to have dreams of greater emotional intensity and “morbid” emotional content, as well as sleep problems such as nightmares, sleepwalking, and teeth grinding than secure individuals.

In surveys of dream content, a majority of people report erotic dreams. And for people in relationships, these dreams contain “high rates of infidelity, whether people report being in healthy relationships or unhealthy relationships,” says Jandial, neuroscientist and author. But erotic dreams have rules, too, he notes. “When you look at the pattern of erotic dreams, the acts seem to be wild, but the characters are surprisingly narrow. Celebrities, even family members, repellent bosses; it’s a small collection of people as a pattern.” Jandial and other researchers theorize that having sexual dreams about people familiar to us may be a feature our brains evolved to keep us open to procreation and increase the likelihood of the species’s survival.

Can Dreams Predict the Future?

Some researchers claim to have evidence that dreams offer a glimpse of the future, but there is not enough evidence to prove it. The phenomenon of precognitive dreams is connected to the experience known as déjà rêvé—the feeling of dreaming something before it happened. Déjà rêvé (which translates as “already dreamed”) is relatively common, especially among the young. As therapist and dream expert Leslie Ellis, PhD, says: “Dreaming is a phenomenon where time does not follow the strict linear rules of the day world. In dreams, we often have a mix of past, present, and possible future. Dreams that predict the future are called precognitive dreams, a close cousin of the déjà rêvé phenomenon.”

History records several instances in which dreams seem to foretell calamitous future events. Abraham Lincoln is said to have dreamed of his death. Ten days before his assassination, he had a dream in which he saw mourners gathered in the East Room of the White House, and one of them said that they were grieving a president who’d just been assassinated. Although Lincoln appeared “disturbed and frightened” when he recounted this dream, there are also stories that he believed that another president had been killed, not him. In 1966, a 10-year-old girl named Eryl Mai in South Wales woke to tell her mother that she’d dreamed that her school was no longer there and was covered by “something black.” A landslide, subsequently caused by waste from a coal mine in the village of Aberfan, obliterated the child’s school, killing 144 students (including Mai) and teachers. This disaster was evidently forecast in dreams by 76 different people. This led British psychiatrist John Barker to form the Premonition Bureau, which collected other reports of dreams that might be precognitive. (This not terribly successful effort is documented by Sam Knight in his 2022 book The Premonition Bureau: A True Story of Death Foretold). Barker’s was hardly the only attempt to document dreams that might forecast the future.

There may be perfectly logical explanations for such dreams that have nothing to do with psychic phenomena or ESP. Selective recall is one. A person may recall a dream that is more predictive of a future event than other dreams that do not. People with “tolerance for ambiguity” are likelier to experience premonitory dreams. That is, they are more prone to interpret an ambiguous dream as predictive of a future event. Those who believe in precognitive and paranormal dreams are likelier to have such dreams. And then there are individuals who, once they experience an event, may recall a dream that seemed to predict it.

Finally, some subconscious wishes may express themselves in a dream, even though the person is already consciously prepared to act on that wish. In this sense, the dream is considered precognitive when the dreamer’s mind is primed. For instance, you might dream of purchasing a new bed and then see an ad for a new one shortly after you wake up. But you might have been thinking about redecorating your house, so the dream only reflected that intention, even if it wasn’t uppermost in your consciousness.

This isn’t to say that there might not be some science behind the experience of precognitive dreams. In his book, The Oracle of the Night: The History and Science of Dreams, the neuroscientist Sidarta Ribeiro allows for the possibility that dreams could have a “predictive” function. “[Your dream is] not a deterministic oracle that can predict what’s going to happen, but rather a very sophisticated, probabilistic, neurobiological machine” that simulates possible futures based on what happened in the past. “On top of the neurological processes at play, you have the dream level that’s symbolic and related to your life in a predictive manner,” meaning that some of the dreams may eventually prove true to your experience. Our dreams present us with various scenarios that show us what the future could look like based on what we know of the past. One of those scenarios may be close to what occurs. Whether that means the dream is precognitive or more like a game of roulette where you make the right bet sooner or later is an unanswerable question.

 

Author Bio: Leslie Alan Horvitz is an author and journalist specializing in science and a contributor to the Observatory. His nonfiction books include Eureka: Scientific Breakthroughs That Changed the World, Understanding Depression with Dr. Raymond DePaulo of Johns Hopkins University, and The Essential Book of Weather Lore. His articles have been published by Travel and Leisure, Scholastic, Washington Times, and Insight on the News, among others. Horvitz has served on the board of Art Omi and is a member of PEN America. He is based in New York City. Find him online at lesliehorvitz.com.

Source: Independent Media Institute

Credit Line: This article was produced by Earth | Food | Life, a project of the Independent Media Institute.