Dreams are a source of mystery. They have changed the course of individual lives and the world, spurring business deals, inspiring art and scientific breakthroughs, triggering military invasions and mental breakdowns. Yet the source of dreams is not mysterious. They are the product of an extraordinary transformation that occurs in the brain each night when we sleep.
In this interview, I speak to pioneering brain surgeon & neuroscientist Rahul Jandial (author of ‘This is Why You Dream’) about the extraordinary way neuroscience and medicine are helping us unlock the fundamental question of why we dream, the impact dreaming has on our lives, and how dream science is helping us with everything from medical diagnoses to improving our mental and physical performance.
Dual-trained brain surgeon and neuroscientist Rahul Jandial, MD, PhD, is a Sunday Times bestselling author with books translated into over ten languages. Jandial undertakes complex cancer operations and oversees groundbreaking science at the Jandial Lab in Los Angeles. He is also the Founder of International Neurosurgical Children’s Association, where he leads teams to teach and perform pediatric brain surgery in charity hospitals throughout Central and South America, and Eastern Europe. Jandial’s first book, Life Lessons from a Brain Surgeon, became a Sunday Times Bestseller. His next book, This Is Why You Dream, will be published in 25 countries and in 20 translations.
Jandial is a long-term contributor at KTLA-TV in Los Angeles and for the TODAY Show in Australia. He hosted Brain Surgery Live on Nat Geo with Bryant Gumbel for international broadcast and was on FOX’s primetime non-scripted Superhuman as a panelist. Jandial has been called “world’s most dashing neurosurgeon” (Variety), “the real Dr. McDreamy” (ABC News), and VICE refers to him as the 100 percent emoji-human version. He has been featured in The Times of London, The Telegraph, Cosmopolitan, Mr. Porter, and GQ, and is an expert for Guardian Masterclasses.
Q: What does neuroscience know about dreams?
[Dr. Rahul Jandial]: Neuroscience provides us with the most insightful glimpse into the biology and electrophysiology of dreams. It isn’t about individual dreams, but rather the universal process of dreaming. Consider how neuroscience has utilized various advanced technologies—such as fMRIs, which monitor blood flow, and electrodes placed on the scalp to measure brain electricity. Originally, these tools were developed for patient care. However, driven by curiosity, neuroscientists began to explore further. Now, these machines are used in hospitals for research beyond disease pathogenesis, investigating our emotional and physiological responses to stimuli like images viewed during an fMRI scan. This approach extends even to the study of dreams.
It’s important to note that there’s no dedicated “dream science” discipline in academia; you won’t find a Professor of Dream Science at a university. Instead, we piece together insights from various scientific fields. I was as surprised as anyone to discover that lucid dreaming is backed by rigorous scientific research—enough to dedicate two of the nine chapters in this book to it. This was a significant learning moment for me. Nevertheless, there are still gaps in our understanding, ranging from erotic dreams to nightmares. It’s up to someone to gather these new pieces and attempt to craft a narrative about dreams. That’s what I’ve aimed to do in this book.
Q: Why do we dream?
[Dr. Rahul Jandial]: That’s a massive question. Rather than offering a conclusion or my current thoughts, let me guide you through the story. Up until about a century ago, it was commonly believed that both the body and brain rested during sleep. So, when people awoke with fantastic ideas and vivid experiences, it seemed natural to assume these had to come from outside the brain, perhaps divinely inspired, as the brain was thought to be inactive.
This notion changed around 60 to 70 years ago, thanks in part to a neurosurgeon named Penfield, who pioneered Awake Brain Surgery. During these procedures, the brain feels no sensation from being touched directly—it only perceives through nerves extending throughout the body. By numbing the scalp, removing a portion of the skull (akin to ice fishing), and waking the patient during surgery, Penfield could stimulate the brain’s surface. He discovered that applying a slight electrical current could trigger vivid recollections of long-standing nightmares in patients, presenting undeniable evidence that dreams originate within the brain.
This finding is still profoundly significant. It’s a point that could spark discussions in both pubs and lecture halls, illustrating the practical approach I’ve taken in unpacking this topic. If dreams are brain-generated, then understanding brain activity during sleep becomes crucial. Similar to how an EKG measures heart activity through electrodes, an EEG does the same for brain activity. Dr. Berger, the inventor of the EEG, noticed that brain electricity continues even during sleep—a pivotal revelation.
This continuous activity during certain sleep phases, especially those associated with vivid dreams, is so intense it resembles waking brain activity, a phenomenon dubbed paradoxical sleep. It challenges the notion that the brain ‘rests’ during sleep. Instead, the dreaming brain is energetically consuming glucose and bustling with electrical activity, suggesting that dreaming serves a critical evolutionary function.
If we accept that the dreaming brain is active, then we must explore its purpose. Unlike the waking brain, the dreaming brain shows reduced executive function, specifically in areas like logic and mathematical reasoning—which aligns with observations that dreams rarely involve such tasks. Instead, areas like the default mode network, which I’d argue functions as an imagination network, along with emotional centers, are highly active. This configuration makes the dreaming brain less logical but more emotional, visual, and imaginative.
Why do we dream? The brain’s activity during dreams suggests it’s preserving or cultivating something essential. Some theories propose dreams as a form of threat rehearsal or a nocturnal therapist. I believe it’s more fundamental: similar to the ‘use it or lose it’ principle that applies to muscles, our brains engage in a nightly routine that stimulates thoughts and ideas not typically relied upon during the day. This built-in process keeps our thinking adaptive and nimble, fostering divergent thoughts and offering an evolutionary advantage. That’s the broader concept I’m exploring.
Q: Does dreaming allow us to process our waking time?
[Dr. Rahul Jandial]: I’m not a computer science expert, but as I’ve delved a bit into this area, particularly around AI, what’s intriguing is how dreaming introduces noise into our system. Consider our brain: a pulsing electrical network teeming with neurons. During the day, we strive for efficiency. The brain forms habits to avoid wasting energy on unnecessary tasks, like finding a new route to work daily or learning to tie shoelaces. It automates routes, like driving on autopilot through the same freeways in Los Angeles, sometimes arriving home without recalling the journey. This efficiency undoubtedly has its benefits, especially in a resource-limited or competitive environment shaped by evolutionary pressures over millennia.
So, why dream? There’s a compelling hypothesis in the field of machine learning called “overfitting,” where systems become so tuned to recognizing patterns that they falter when faced with new, unexpected scenarios. This concept, known as overfitting, highlights how patterns can become too rigid. Interestingly, some computer scientists are exploring ways to inject noise into computational models to keep them adaptable.
Reflecting on this, consider our involuntary engagement with dreaming. We don’t choose to dream, yet we can’t avoid sleep. After just a day or two without sleep, a pressure builds, compelling us to sleep. It’s the brain that drives this urge, not organs like the liver or heart. What’s remarkable about the brain during sleep? It dreams. If you miss a day of sleep, your next sleep session plunges you into dreaming quicker.
This leads me to a bold assertion—though it’s my opinion, not a scientific measurement—that we sleep because we must dream. Yes, sleep has metabolic benefits, but a crucial aspect seems to be that our neurons need to dream to maintain their capabilities. This prowess is crucial for imaginative thinking, developed in an evolutionary context where environments are constantly shifting and changing. This ability to adapt and think creatively is essential, and dreaming plays a key role in fostering this adaptability.
Q: Is the study of dreaming helping us understand consciousness?
[Dr. Rahul Jandial]: Yes, let’s delve into that a bit more. The experience of inhabiting a dream feels as real as life itself, and I often liken it to being in the driver’s seat of a car that we can’t control. This is distinctly different from the dissociative states induced by psychedelics, where some patients report feeling as though they are floating above the room upon waking. Psychedelics can provide a shift in perspective and a detachment from our usual self-centered viewpoint, often described as ego dissolution. However, in dreams, you are fully immersed; everything happens around you, making the experience feel intensely real.
Part of this vivid realism in dreams might be explained by brain activity: when you run in your dreams, for instance, the motor strip—responsible for moving your legs—is active, generating electricity. This occurs while your body is temporarily paralyzed from the neck down, preventing you from acting out the dream’s scenarios—a safety measure, in my opinion, though the fact remains that the body is paralyzed.
The experiences you have in dreams, measured by brain activity and glucose consumption, are remarkably similar to those you would have while awake. Consider the implications: the brain runs simulations that are indistinguishable at the neuronal level from real-life actions. For example, whether you’re running the London Marathon in reality or dreaming about it, your brain’s electrical and metabolic patterns are nearly identical. These are not just speculative statements; they are based on measurements, and I encourage people to draw their own conclusions from them.
Switching focus to consciousness, this remains a challenging topic. It’s clear to me that consciousness isn’t solely a human trait; my puppy, for example, undoubtedly possesses consciousness, evidenced by its ability to connect with humans. This suggests that consciousness has evolved across different branches of species through what is known as convergent evolution, similar to the development of eyeballs, which appear to be an evolutionary advantage for many species.
When discussing consciousness with my three sons, all currently in university, I describe it as an emergent phenomenon. Imagine 80,000 people in a stadium, each one representing a neuron. The collective roar you hear when you approach the stadium might be likened to consciousness—this is the closest analogy I can offer. Dreaming, too, feels entirely real because, at the level of neuronal activation in the dreaming brain, it essentially is real. This, of course, is my opinion, but it underscores the profound nature of our dreaming consciousness.
Q: What do we know about lucid dreaming?
[Dr. Rahul Jandial]: …people were often surprised that a brain surgeon, who spent time growing neurons in a lab, would have an opinion on lucid dreaming. Initially, I too thought the concept might be fringe or “woo-woo”—more metaphysical than neuroscientific. However, as I delved deeper, dedicating two of the nine chapters in my book to this subject, I discovered many of my assumptions about dreams were incorrect. Indeed, some aspects of dreaming are surprisingly well-supported by science, while others remain as elusive as dreams themselves should be. No one should claim to have it all figured out, but I’m delighted to share some insights with you and your readers.
Lucid dreaming has been discussed for millennia, even by Aristotle about 2000 years ago. The topic gained significant traction in the neuroscience community in the 1970s and 80s when it was first proven to be possible. How was this proven? Let me walk you through the experiment because the details are crucial.
We use electrodes to detect brain activity, including the specific patterns known as sleep spindles. Initially, I was skeptical, suspecting people were just pretending to wake up. But these electrodes provide electrical proof that a person is genuinely asleep. Despite the body being paralyzed to prevent acting out dreams, some functions like breathing and reflexive movements continue, and crucially, eye movements are preserved. Researchers in sleep labs observed people who, while proven to be asleep through electrodes placed around their eyes and on their heads, began communicating with observers using predetermined eye movements, such as moving their eyeballs to the right three times to signal the onset of lucid dreaming.
In lucid dreams, unlike the random eye movements typical of REM sleep, these signals are highly coordinated. Upon waking, participants confirmed these movements coincided with the moment they became aware they were dreaming. Further proof includes changes in the brain’s activity, notably in the dorsolateral prefrontal cortex, an area responsible for executive functions, which shows increased activity as awareness in the dream returns.
Moreover, the neurotransmitter acetylcholine, commonly discussed alongside others like dopamine and serotonin, plays a role here too. Its synthetic form, galantamine, used to treat dementia, has been shown to increase the frequency of lucid dreaming in a dose-dependent manner, suggesting a causal relationship.
Additionally, it turns out you can teach yourself to lucid dream, and many report not only experiencing lucid dreams but also being able to influence the direction of those dreams. About a third of people can do this. Even the team that helped publish my book reported dreaming more during the process.
So, from Aristotle’s discussions to modern pharmacological and blood flow evidence in fMRIs, lucid dreaming is supported by robust scientific evidence. It’s not just about crystals and wishful thinking, as some might jokingly suggest back in Los Angeles. Engaging deeply with this topic has significantly shifted my own perspective.
Q: How is the study of dreaming helping us understand medical conditions?
[Dr. Rahul Jandial]: That’s an important question. I’ll start with some measurements and then share my opinions. Most people don’t typically experience nightmares. PTSD-related nightmares are often flashbacks, directly tied to the traumatic event. Then there are the imagined nightmares involving monsters and other fantastical elements. If you’re an adult and suddenly start having nightmares—a term we call “new onset” in medicine—it’s noteworthy. While children frequently experience nightmares, which I believe might play a role in developing their young minds, the occurrence diminishes as they grow.
For adults, having nightmares occasionally is generally normal and not indicative of underlying issues. However, if these nightmares begin unexpectedly and persist or increase in frequency, they could serve as a psychological thermometer. This change might signal underlying issues that you are not consciously aware of yet. It’s like a warning that could precede any conscious recognition of distress in your waking life.
So, it’s not just the nightmare itself, but the trajectory of these nightmares that’s important. A sudden increase in nightmares could be a cue to delve deeper into what might be underlying these disturbances. This leads me to discuss something quite fascinating called dream enactment behavior, or what is technically known as REM behavior disorder. This was something unknown when I was in medical school 50 years ago. Typically seen in men in their 50s, they start acting out their dreams, often resulting in accidental injury to their bed partner, believing they are defending someone. Alarmingly, statistics show that almost all of these individuals, in the high 90s percentile, develop Parkinson’s disease about 10-15 years later.
This change in dreaming patterns could be the brain’s early warning system of impending neurological decline—a solar flare of sorts, signaling for help. It’s quite profound when you think about it: a significant medical condition foreshadowed by changes in how we dream. This is discussed in detail in Chapter 5 of my book, which ties into medical aspects.
Another intriguing phenomenon I’ve encountered is paradoxical kinesis. This occurs in Parkinson’s patients who typically suffer from movement and speech rigidity. Yet, when these patients act out their dreams, their movements and speech become fluid and unrestricted. It’s as if the dreaming brain takes control, allowing them to move and speak freely. This paradox is not something I can fully explain, nor do I want it explained just yet. It’s a marvel to reflect on and is purely an observation, not merely an opinion.
These discoveries have reshaped my views on creativity and the brain’s function, much like how a visit to the National Gallery or the Tate might inspire new perspectives. It underscores that there’s something profound being orchestrated by our brains at night, far from the quiet processing we might assume happens during sleep. This has led me to reconsider the “a-ha” moments I experience during the day—not as products of an executive network with enhanced processing power, but as insights fed by this nocturnal activity.
Q: What does legacy mean to you?
[Dr. Rahul Jandial]: My concept of legacy has evolved over time. It first took shape when I became a father at 28. At that point, my legacy centered around my sons—providing them with roots and wings, and teaching them about the world and interpersonal dynamics. There’s a cognitive inheritance I aim to leave them; this was my initial, sensitive legacy.
However, the way you’re catching me now, with this book and at a point in my life where my sons are driving their own paths—one in San Francisco, another bound for Manhattan, and the third near DC—has made me reflect on my legacy beyond just being Dr. Jandial, the cancer surgeon, or as a dad. Now at 51, dreaming has helped me shed my preconceived notions, and I find myself wanting to shed these titles as well.
Currently, my cherished legacy is twofold. Firstly, I recognize the importance of the content we produce—like this interview, for which I thank you—and the content I’ve been creating since I was 35. We live in a critical era where nearly every thought is recorded and available for future generations, placing us at a unique ground zero of historical record-keeping. It’s crucial to me that what I put out into the world is meaningful.
Secondly, this book—the 600th page of my third publication with Penguin, and not one of my academic texts—represents a significant part of my legacy. I hope to be remembered for exploring the brain and the mind through stories, personal struggles, and deep inquisitiveness, offering a fresh perspective rather than claiming it to be the right or wrong one. This work, I hope, will serve as a resource for others to learn from and benefit.
Ultimately, my books and interviews like this one are both my hello and goodbye to the world. They encapsulate a lot of my evolving thoughts and content, ensuring that my legacy endures.