‘History is a nightmare from which I am trying to awake.’ — James Joyce
As a grad student in psychology in the early 1990s, Finnish psychologist Antti Revonsuo often had bad dreams. What struck him the most was how lifelike they were. (…) You move around, talk, run, interact with others, experience emotions, and feel the passage of time, just as in everyday life.
When Revonsuo began studying dreams, he asked his students to start keeping logs of their own nocturnal escapades. He noticed something striking. The dreams were filled with dangerous events, negative emotions, monsters, chases, escapes, fights, and near-death experiences. The dream world was a hellscape of danger, teeming with threatening events far more sinister than in waking life.
These weren’t the misfirings of diseased brains. Threat dreams were the norm, accounting for a staggering two-thirds of all dreams. Revonsuo discovered that we grossly underestimate the number of nightmares we have. As it turns out, we have 300 to 1,000 threat dreams per year—one to four per night. Just under half are aggressive encounters: physical aggression such as fistfights, and nonphysical aggression such as verbal arguments. The rest are about car crashes, falling and drowning, missing a meeting or a test, being lost or trapped, and being naked in public. The whole dream world seemed to have a negative bias: more negative emotions than positive ones, more nightmares than fantasy.
In the ancestral environment, Revonsuo reasoned, our dreams served to protect us, teaching us how to respond when a wild animal was chasing us or when we got lost in the forest. That was why the dream world was so filled with peril: to simulate the potential threats and prepare us to react quickly. But how could dreams help us select the optimal response, given that dream recall is so fragile? After all, we remember only a few of our dreams, and even those fade fast in the tumult of the day.
Revonsuo believes that by providing rehearsal, dreaming helps us recognize dangers more quickly and respond more efficiently. We don’t need to be aware of this rehearsal, just as you don’t have to recall exactly where you practiced your tennis serve in order to reap the rewards.
The idea that dreams are a dojo for perfecting waking activities fits well with what is already known about practice. Mental rehearsal through visualization improves skills, enhances learning, and changes the brain, polishing performance in almost any domain, from sports to piano playing.
The single most pervasive theme in dreaming is that of being chased or attacked. Just as athletes in training repeat parts of their performance, we may, in our nightmares, be attacked and chased over and over again, not to solve a particular problem but to actually practice efficient escape behavior. (…)
The dreaming brain, explains Revonsuo, scans emotional memories. When it detects a memory trace with a strong negative emotion, it constructs a nightmare around that theme. The more traumatic the event, the more intense the nightmare. The brain’s system for detecting threats is sensitive and flexible: Anything the brain tags with a strong negative charge gets thrown into the threat bin and dredged up at night.
Sometimes this system works well: Dreaming about a boy running in front of our car better prepares us should that danger crop up in real life. But sometimes the modern world throws the threat-detection mechanism out of whack: Watching horror movies can trigger nightmares about vampires, ghosts, aliens, or zombies. Such “nonsense nightmares” don’t rehearse any useful threats; they’re like an allergic reaction, says Revonsuo. Just as our immune system can mistake pollen for a pathogen and mount a defensive campaign, the threat-detection system misperceives horror movies and deploys its defenses by generating a nightmare.
artwork { Golan Levin, Opto-isolator, 2007 | paint, mechatronic circuits, acrylic, custom software, computer, ABS enclosure }
