7 surprising facts about dreams -- why we have them and what they mean

I had a nightmare last night.

It began like many of my dreams do – I was on vacation with my extended family. This time, we were in Australia, visiting family friends in a big house. Things took a turn when — in some way that I can’t quite explain — I got mixed up in this Australian family’s jewelry theft and smuggling operation. And I lied about it in front of my relatives, to protect myself and my co-conspirators. Before I woke up, I was terrified I’d be sent to prison.

The dream seems bizarre, but when I pick the narrative apart, there are clear connections to my waking life. For instance, I recently listened to a podcast where a pair of fancy hairpins suspiciously go missing during a family gathering. Moreover, I’m moving tomorrow and still have packing to do. When the movers arrive in the morning, if I haven't finished packing, I'll face the consequences of my lack of preparedness – a crime, at least to my subconscious.

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Dr. Rahul Jandial, neurosurgeon, neuroscientist and author of This is Why You Dream: What Your Sleeping Brain Reveals About Your Waking Life, says the major themes and images of vivid dreams like these are worth paying attention to, and trying to derive meaning from. (For me, I decided that the next time I have to move, I’m taking the day before off!)

I spoke with Dr. Jandial about what else we can learn from our dreams, including some of modern science’s most remarkable findings, and theories, about the dreaming brain.

1. Dreams are not random

From dream diaries recorded in ancient Egypt and China to reports from anthropologists in the Amazon, to surveys of modern Americans, evidence shows our dreams have a lot in common. For example, being chased and falling are pretty consistent.

“Reports of nightmares and erotic dreams are nearly universal,” Jandial says, while people rarely report dreaming about math. Jandial says the lack of math makes sense because the part of your brain primarily responsible for logic — the prefrontal cortex — is typically not involved in dreaming.

2. Our brains are super active when we dream

Jandial learned something fundamental about dreams in the midst of performing brain surgery.

It was awake surgery – he’d numbed the scalp and partially opened the skull. (The brain does not feel pain). Jandial was operating on the left temporal lobe, where language is typically located. Working carefully to avoid damage, he went millimeter by millimeter, stimulating the neurons, and asking the patient to count to ten at each spot.

But after one such zap of electricity, Jandial’s patient experienced a nightmare that had recurred for him since childhood.

Research has since confirmed that nightmares, and all dreams, arise from brain activity. “Now we know from different measurements of electricity and metabolic usage, the sleeping-dreaming brain is burning hot. It's sparking with electricity. We might be asleep, but the brain is on fire,” Jandial says.

3. When you first wake up, or while you're drifting off, is fertile time for creativity

Salvador Dali had a method for capturing his thoughts just as he was falling asleep, which Jandial recounts in This is Why You Dream. The artist would sit in a chair holding a large key above a plate on the floor. When he nodded off, the key would drop on the plate and wake him up. Then he’d sketch what he remembered from the last few moments of sleep – an inspiration for his surrealist paintings. Brain imaging studies support the potential of sleep-entry as a moment of insight, says Jandial.

Fortunately for those of us who prefer to fall asleep and stay there, thank you very much, you can also get inspiration from your dreams when you first wake up. “I get all my ideas when I wake slowly,” Jandial says. He writes down what he remembers in the first few minutes after waking, before checking the news or Instagram. It’s not all great stuff, “But when there are good ideas, it's from that time. It's not from two o'clock with my espresso,” he says.

4. Nightmares? Write a new script

Jandial says nightmares around occasional stressful events, like my dream about the jewelry heist – are usually not cause for concern. But if you’re stuck in a loop of recurring fearful dreams, there is something you can try: Imagery Rehearsal Therapy.

This is something you can do with a therapist. “If [a patient has] a recurrent nightmare of an explosion or an airplane crashing, they'll go to the therapist to draw out the map of the dream, the dreamscape, if you will, and then they'll rehearse that the airplane landed safely,” or that they arrived home from a drive instead of crashing, Jandial explains. After time, he says many patients see their nightmares change.

5. Dreams about cheating are normal. They don’t mean there's something wrong with your relationship

In surveys, 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,” Jandial says.

But sexy dreams have rules too. “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 others 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’ survival.

6. Near the end of life, dreams can provide comfort

Treating patients at City of Hope cancer center in Los Angeles, Jandial observes a phenomenon he calls “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 says there’s 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,” Jandial says.

7. Dreams can be ‘a portal to your inner self’ — and mental health

Everyone has anxiety dreams from time to time. Some are literal, like dreaming you’re on a podium naked when you actually have to give a speech the next day, says Jandial. But others can be more symbolic, and these are worth tuning in to.

Jandial remembers one he had during the pandemic. In waking life, he’d just learned to sail. In the dream he was sailing a boat and, “there was a massive waterfall,” he recounts. “And I was sailing horizontally and I had to constantly keep the helm, or the wheel, up-river just to go straight and not fall off.”

He interprets it as his brain’s way of helping him process a difficult time. He was raising teenagers and working as a cancer surgeon amid COVID fears. “There were wars on many fronts for me at that time. And what I walked away with is just by avoiding going all over the waterfall, you're doing it.”

He says if you have a powerful dream, it’s worth thinking about why. “Dreams with a strong emotion and a powerful central image, those are ones not to ignore,” he says. “The dreaming brain is serving a function, and if it gives you a nugget of an emotional and visual dream, reflect on that. That's a portal to yourself that no therapist can even get to.”

And repeated anxiety dreams, he says “I think that's something to pay attention to. That might be a vital sign for your mental health.”