Jung Tsai

I recently picked up a collection of short stories for summer reading. The opening tale was about a “dream on fire.” It shows two young people who meet at a party and feel an instant connection. The girl has had a vivid recurring dream since childhood. While some of her dreams are grand—like winning the lottery—most are trivial that predicting minor events of the very next day. But this time, she dreams that her new acquaintance is trapped inside a burning building. Though it was just fiction, it struck a chord. Dreams are a universal human experience. We all do it. Don’t we?

The dictionary defines a dream as a series of thoughts, images, or emotions occurring during sleep. But the word stretches far beyond the night. It represents our daydreams, our most cherished goals, and cultural ideals like the “American Dream.” In 2019, I was honored to be recognized as a congressional “dream maker” for my work as an immigrant. But as a doctor, I want to step away from the metaphors and talk about the actual, biological mysteries of the sleeping mind.

For millennia, we have tried to decode the night. From the Egyptian “Dream Book” of 2070 BC and ancient China’s (周公解夢）Zhougong’s“Book of Dreams”to Sigmund Freud in the early 20th century of “Interpretation of Dream”. Human history is filled with dream interpretation. Dr.Freud, the father of psychoanalysis, famously argued that dreams are the window into our deepest psychological distress, acting as a mirror for repressed desires. Yet, despite being nominated for a Nobel Prize 32 times, Freud was repeatedly rejected. The reason? The committee felt his work was merely speculation—not science.

The turning point came in 1924. That was the year German psychiatrist Hans Berger recorded the very first electrical signals (EEG)from a human brain. Decades later, in 1953, researchers at the University of Chicago discovered Rapid Eye Movement (REM) sleep—the active state where most of our dreaming occurs. Suddenly, sleep laboratories bloomed like mushrooms across the globe. By tracking brain waves alongside a sleeper’s written dream logs, scientists finally turned dreaming into a legitimate medical specialty. What we learned was astonishing: when you sleep, your brain does not rest. Instead, your brain cells literally shrink to allow fluid to flush out the daily accumulation of cellular waste staying in between cell’s spaces. At the same time, your mind is busy transferring short-term memories into long-term storage for ready retrieval.

Every night, your brain cycles through four or five of 90-minute sleep stages I-IV:

  • Stage I: A light, short drifting drowsiness where your muscles relax but hands still able to hold on subjects.
  • Stage II: Your heart rate and breathing slow down as brain waves take on a gentle, rhythmic pattern. Subjects in hands will drop.
  • Stage III: Deep, long restorative sleep. This is where sleepwalking happens, and it is incredibly difficult to wake someone from this state. Above are NREM(non).
  • Stage lV: REM Sleep,Often called “paradoxical sleep“is a state your brain is electrically active as when you are wide awake, but your body is completely paralyzed to prevent you from physically acting out your dreams. Most dreams happen here.

Most modern sleep scientists believe that these vivid, bizarre dreams act as an emotional thermostat. They process harmony, rejection and strengthen our mental resilience, even help regulate our immune systems. And yet, some still argue dreams are just a meaningless by products of neural firing. Then, in 1977, a Harvard scientist Allan Hobson discovered that REM sleep is triggered physically by the brain stem-Pons, which randomly activates stored memories, forcing the mind to synthesize them into a story. Interestingly, patients with damage to the brain stem lose REM sleep but still dream, while patients with prefrontal lobe damage lose their dreams entirely but still experience REM sleep. Dreaming, it seems, is the ultimate brain teamwork from many areas. Because sleep occupies one-third of our lives, depriving sleep means depriving dreams. It carry consequences of poor life. My researchers convince me that dreaming is a vital evolutionary tool designed to improve our physical and psychological survival.

This brings us to the next, thrilling frontier of medicine “Dream Engineering.” :

  • We all know general anesthesia can induce dreams that help to diminish fear from PTSD. Moreover, We are rapidly approaching a future where technology can actively shape our sleep and dream. Scientists are developing “dream incubation” tools that using targeted sound, smell, touch, taste  or motions to influence what you see behind closed eyes. Today, you can download apps designed  from MIT to program your subconscious mind to construct a dream specific to your need.
  • But this frontier has a dark side. Corporate giants are already preparing for a future where they don’t just target you with advertisements while you are awake—they want to beam commercials directly into your bedroom while you dream. Imagine a world where companies can manipulate your sleeping mind to influence your smoking habits, games playing, gambling addictions, purchasing decisions to impulsive buyers. Governments are already waking up to the frightening potential for criminal exploitation and unfair manipulation in this hidden space.

Ultimately, a dream—much like a beating heart—is there to serve our fitness. Recently, I have been dreaming vividly about my past: performing my first major liver resection, executing complex vascular surgeries, and walking up steep hills with my son during his college searches. These dreams did not feel like random noise. They brought back the vitality, fearlessness, and raw energy of my youth.

Every morning, before heading to the gym at 6:00 am, I now sit on the edge of my bed for five minutes. I purposely replay both good and bad dreams in my mind, catching the images before they evaporate into the daylight and jot down diary. These reflections make my new days brighter, bolder, and more focus.

I have decided to wake up five minutes earlier every day to weave the adventure of my night into the actions of my day. I invite you to do the same. There are happy hours you never want to end, there are weird, bizarre, hurting passages that doesn’t make sense. But It’s a constant reminder that life have its up and down. Dreams make us human. They help us prepare the risks and uncertainties. Your dreams matter. They have the function to embolden,empower,and humble you. Take that insight with you tomorrow morning, the next day, and every day after.

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