Why do we spend a third of our lives dreaming? In his book This Is Why You Dream, neurosurgeon Rahul Jandial argues that dreams aren’t random mental noise—they’re essential neurological processes that keep your thinking flexible, process difficult emotions, spark creative breakthroughs, and help form your identity.
Through firsthand observations and cutting-edge research, Jandial explains how dreams work, what they reveal about your inner life, and how you can actively shape them. In our overview of This Is Why You Dream, you’ll also learn how to interpret your dreams using a two-step method based on brain science, manage recurring nightmares, harness sleep states for creative problem-solving, and even practice lucid dreaming.
Overview of This Is Why You Dream
Have you ever woken from a dream so vivid that it stayed with you all day—or been jolted awake by a nightmare that left your heart racing? Dreams can feel like mental noise or weird movies our brains play while we sleep. But according to neurosurgeon and neuroscientist Rahul Jandial, dreams are far from random. In his book This Is Why You Dream, Jandial argues that dreams serve critical functions: They keep our thinking flexible, process our emotions, spark creative breakthroughs, and help form our identity.
As a neuroscientist and brain surgeon, Jandial has studied what the brain does when we dream, and he’s witnessed firsthand how deeply dreams are embedded in the brain’s architecture: During awake brain surgeries, stimulating specific brain regions can trigger patients’ recurring nightmares. Jandial published This Is Why You Dream in 2024 to share what science has revealed about this mysterious aspect of consciousness, and he’s authored other books including Life Lessons From a Brain Surgeon and Neurofitness.
Jandial’s understanding of dreams challenges conventional wisdom: While scientists long thought dreams only occurred during REM (rapid eye movement) sleep, Jandial emphasizes research showing that dreaming can happen during any sleep stage, meaning we spend far more of our lives dreaming than previously thought. He also argues that while we think of dreams as byproducts of sleep, we may actually sleep because we need to dream.
What Are Dreams?
Jandial explains that dreams are the product of electrical activity in your brain. During awake brain surgery, where the patient remains conscious, they feel no pain when a surgeon touches their brain with an electrical probe, since brain tissue has no pain receptors. But when the probe delivers a tiny jolt of electricity to specific brain regions, the patient experiences vivid memories, sensations, emotions—and sometimes the same terrifying scenarios they experience as nightmares during sleep. This reveals that the brain regions active during dreaming can be stimulated to reproduce dream experiences, proving that dreams are encoded in the structure of your brain as specific patterns of neuronal activity that can be triggered and measured.
Jandial emphasizes a recent discovery about dreaming. Your brain cycles through different sleep stages, and scientists long believed dreams only occur in REM (rapid eye movement) sleep, a stage that occupies about two hours per night. But newer research shows dreaming can occur in any sleep stage—which means we might spend a third of our lives dreaming. To understand how your brain creates these dream experiences, we’ll look at what parts of the brain are involved in dreaming, how their roles change when you fall asleep, and why your brain is so active as you dream.
Your Brain’s Two Operating Modes
Jandial explains that your brain has two distinct operating modes, each controlled by a different network of brain regions: the Executive Network and the Imagination Network.
The Executive Network is your brain’s logical control center, anchored in the prefrontal cortex, the outer layer of brain tissue right behind your forehead. This network handles rational thinking, planning, reality-testing, and judgment. It evaluates whether something makes sense, recognizes whether something is impossible, and makes deliberate decisions. When you’re awake and focused on a task, your Executive Network is in charge of keeping your thoughts organized, checking whether your thoughts align with logic and make sense in the real world.
The Imagination Network includes regions distributed throughout the outer cortex, along with deeper emotional centers. This network activates when you’re not focused on a specific task. The Imagination Network is responsible for mind-wandering, daydreaming, memory association, and visualization. Jandial explains that while the Executive Network constrains your thinking to what’s logical, the Imagination Network makes connections, visualizes hypotheticals, and asks “what if” questions.
How Your Brain Creates Dreams
When you’re awake, these two networks take turns: When you focus on work, the Executive Network dominates. When your mind drifts, the Imagination Network takes over. Jandial notes that dreaming occurs when this balance shifts through three simultaneous changes.
First, your body becomes paralyzed. As you sleep, your brain releases neurotransmitters (chemical messengers) that deactivate the motor neurons in your spinal cord. These nerve cells transmit movement commands from your brain to your muscles. Deactivating them paralyzes all of your voluntary muscles except for those controlling your eyes and your breathing. This is a crucial safety mechanism because your brain can’t distinguish between dreaming about performing an action and actually performing that action. If your motor neurons weren’t deactivated, you would act out your dreams.
Second, your Executive Network shuts down. Jandial says this happens through a series of neurochemical changes in your brain, most crucially a drop in levels of adrenaline, a neurotransmitter that helps you stay alert and focused when your Executive Network is in charge. Adrenaline helps you distinguish relevant information from background noise and evaluate whether things make logical sense. Without adrenaline, your brain can no longer separate signal from noise. The bizarre narratives of dreams can unfold because your brain’s reality-testing mechanism is offline.
Third, your attention turns entirely inward, activating the Imagination Network. With your eyes closed and sensory processing dampened, your brain enters stimulus-independent cognition: It generates thoughts, images, and narratives without external prompts. Jandial explains that neurons naturally produce spontaneous electrical activity. During dreams, the Imagination Network takes this electrical activity and weaves it into narratives by searching your memories for loose associations, connecting unrelated concepts, and visualizing hypothetical scenarios. Without the Executive Network active, you accept whatever your Imagination Network presents to you, making “dream logic” fundamentally different from waking thought.
The Dreaming Brain Is Highly Active
You might assume that because you’re asleep, your brain is resting or operating at reduced capacity. But Jandial explains that the opposite is true. Using brain imaging that tracks electrical patterns, oxygen consumption, and energy use, neuroscientists have discovered that the dreaming brain is extraordinarily active. While the prefrontal cortex (home of the Executive Network) shows reduced activity during dreams, other regions dramatically increase their activity—in some areas, even more than during waking hours.
First, the limbic system—a collection of structures deep in your brain that processes emotions and memories—becomes hyperactive during dreaming. Jandial emphasizes that the emotional intensity you experience in dreams exceeds what’s possible when you’re awake, which is why dreams feel so real and can affect your mood the next day. The amygdala, an almond-shaped structure within the limbic system that processes fear and other powerful emotions, shows particularly intense activation during nightmares.
Second, the visual processing areas in your brain also show intense activity during dreams, which explains why most dreams are so visually rich. Even people born blind experience dreams, though their dreams rely more heavily on sound, touch, taste, and smell.
Third, the medial prefrontal cortex (mPFC), a region involved in social understanding and self-reflection, remains active during dreams. The mPFC enables you to think about your mental states and imagine what others might be thinking or feeling. During dreams, it helps you create social scenarios and attribute thoughts and motivations to the characters in your dreams.
Jandial explains that this distinct combination of brain activity—with your Executive Network offline, Imagination Network freed, emotional centers supercharged, and visual processing intensified—creates the unique experience of dreams. Dreams feel vivid, emotionally powerful, visually rich, and utterly convincing, even when they make no logical sense upon waking. But given that all of the activity that goes into dreaming requires tremendous energy, what purposes could justify our brains dedicating so many resources to this strange state of consciousness? That’s what we’ll explore next.
Why Do We Dream?
Jandial argues that the universality of dreams across time and cultures—as well as evidence for the biological necessity of dreaming—demonstrate that dreams provide survival advantages. In fact, he proposes that rather than experiencing dreams as byproducts of sleep, we may sleep because we need to dream. When people are severely sleep-deprived, their brains prioritize the most dream-intense sleep stages, plunging immediately into REM sleep rather than following the normal 90-minute sleep cycle. Jandial contends this indicates that intense dreaming is the brain’s top priority.
Dreams Prevent Your Thinking From Becoming Too Rigid
First, Jandial hypothesizes that dreams keep your brain adaptable by injecting randomness into your thinking. During your waking hours, your brain forms efficient habits: You drive home on autopilot, follow familiar patterns at work, and stick to comfortable thought processes. This saves cognitive resources, but it also risks making your brain overly adapted to the patterns you see in your daily experiences—and less able to handle unexpected situations. In dreams, your Imagination Network makes new associations, forcing your brain to process information in novel ways. In evolutionary terms, this flexibility provides an advantage: Our environments constantly change, and a brain that can adapt is most likely to solve novel problems and survive.
Dreams Help You Process Your Emotions
Second, Jandial explains that dreams help you process difficult emotions without the anxiety normally attached to them. When you experience something emotionally challenging while awake, adrenaline surges through your system, binding the emotional content to a stress response. But, as we explored earlier in the guide, adrenaline levels drop to zero when you’re dreaming, so you can re-experience the memory while defusing its emotional charge. For example, research on divorcing couples found that those who had complex dreams mixing old and new memories recovered better from depression than those who didn’t. The dreams helped process negative feelings, allowing people to move forward through a major life change.
Dreams Help You Rehearse Important Scenarios
Third, Jandial explains that dreams create simulations that help you prepare for real-world challenges. Being chased, attacked, or facing threats are common dream themes, and this threat rehearsal during dreams helps you work through problems you might encounter. Jandial notes that dreams also serve as social laboratories: Your brain creates varied scenarios involving realistic and improbable social situations, allowing you to explore how interactions might unfold. This makes evolutionary sense because our survival has always depended on navigating complex group dynamics. The medial prefrontal cortex, which handles social cognition, remains active during dreams precisely to enable these social simulations.
Dreams Spark Creativity and Problem-Solving
Fourth, Jandial argues that dreams enable you to practice divergent thinking: seeing problems from new angles and discovering unexpected connections. With your Executive Network offline, your Imagination Network has the creative freedom to make breakthroughs. Jandial explains that the dreaming brain excels at visual problem-solving. The sleep-entry period (the few minutes as you’re falling asleep) and sleep-exit period (the first minutes after waking) are particularly fertile for creativity because these are transitional states where your Executive Network is partially online but your Imagination Network is also operating freely, giving you both creative freedom and enough conscious control to capture and evaluate ideas.
Dreams Help Form Your Identity
Finally, Jandial argues that dreams help you form your sense of self, especially during childhood. Children don’t begin dreaming until age four or five, coinciding with the development of visual-spatial skills and emerging self-awareness. Nightmares arrive shortly thereafter and serve a specific developmental function: The dream-self faces attack from monsters or evil beings, helping children to establish boundaries between themselves and others and to see themselves as an individual with their own thoughts. Even in adulthood, dreams support your evolving self-understanding by revealing preoccupations and values that your conscious mind hasn’t fully acknowledged.
How Can We Work With Our Dreams?
Understanding why we dream reveals that dreams serve crucial functions—but that doesn’t mean every dream feels helpful. Nightmares can leave you shaken, anxiety dreams can linger all day, and confusing dreams can make you wonder what your brain is trying to tell you. Sometimes dreams feel like they’re working against you. Fortunately, you can learn to work with your dreams in two complementary ways: by interpreting what they reveal about your inner life, and by actively shaping your dream experiences to better serve your needs.
1. Remember Your Dreams
To work with your dreams—to interpret them or shape them—you must remember them. Jandial explains how to improve your dream recall: Before you go to sleep, tell yourself that you’ll dream, remember your dream, and record it upon waking. This primes your brain to prioritize dream retention. Upon waking, write down or voice-record whatever you remember before thinking about your day or checking your phone. The dreams you recall in the morning come from your final REM cycle, which Jandial argues is the most emotional and symbolically rich period of dreaming. Protecting this morning window before distractions intrude can help you gain valuable insight from your dreams.
2. Interpret What Your Dreams Reveal
Not every dream needs interpretation. Jandial explains that some dreams have obvious meanings: Dreaming about an exam before taking one clearly reflects your anxiety about it. Others are tied to major life stages like pregnancy or approaching death, where meanings are self-evident. Some dreams lack emotional intensity and are just mental static. The dreams worth examining are those with powerful emotions, distinct central images, and coherent narratives. These dreams are shaped when your limbic system is in overdrive and can reveal concerns that aren’t obvious to you during your waking life. Jandial proposes a two-step method of dream interpretation.
The first step is to identify the dominant emotion and its intensity. What was the strongest feeling, and how intense was it? Greater intensity indicates a more important dream. The emotions you experience during waking hours shape your dreaming, but the images and plot of the dream can match the emotion while having little connection to its real source.
The second step is to consider the dream’s central image as a metaphor. While you’re dreaming, your brain searches through your memories for other times when you experienced similar emotions and conjures images from those experiences. Jandial explains that this is why universal dream dictionaries that claim specific symbols have fixed meanings don’t work: The same image means different things to different people. Only you can interpret your dreams because only you know your associations, memories, and emotional landscape.
3. Consider What Different Types of Dreams Can (and Can’t) Tell You
Jandial explains that what a dream can and can’t tell you depends on what kind of dream it is.
Nightmares in adults vary in significance. Occasional nightmares around stressful events are normal. But if you suddenly start having nightmares when you previously didn’t, or if nightmares increase in frequency, this can signal issues. Jandial explains that you can think of nightmare patterns as a vital sign for your mental health—changes in frequency or intensity deserve attention. For trauma-related nightmares, the dream’s form indicates your progress: When dreams replay the trauma, you’re still struggling to process the experience. When dreams become more metaphorical, this indicates that you’re processing the associated emotions in a healthier way. This evolution from realistic to symbolic dreams signals psychological healing.
Erotic dreams don’t typically signal hidden desires or relationship problems, even when they involve infidelity. Research shows that erotic dreams rarely reflect our waking sexual life: Most feature familiar people from daily life rather than fantasy scenarios. What these dreams do reveal is information about relationships through the emotions they generate when we’re awake and remember them. In healthy relationships, infidelity dreams have minimal effect on next-day intimacy. In troubled relationships, they correlate with decreased intimacy the following day, likely because they highlight the gap between the dream and difficult reality.
Some dreams warn about physical or mental health issues. Jandial cites the example of dream enactment behavior, where people act out their dreams because the normal sleep paralysis mechanism fails during REM sleep. Men in their fifties who develop this condition have a 97% chance of developing Parkinson’s disease or related neurological conditions within 14 years. Depression also affects dream content: People with major depression experience nightmares more than twice as often as others, and increasing nightmare frequency can indicate declining mental well-being even before other symptoms become apparent.
4. Use Your Dreams to Think More Creatively
One of the most practical ways to work with your dreams is to put your dreaming brain to work on problems you’re trying to solve. To use the sleep-entry period to think creatively, clearly define a problem and think about it as you drift off, keeping a journal nearby to capture your insights. To take advantage of the sleep-exit period, Jandial recommends resisting the temptation to check your phone as soon as you wake up. Instead, linger in the drowsy state and let your mind wander. To use strategic naps to boost your problem-solving, take a 60- to 90-minute nap so you can experience REM sleep, which weaves new information together with past experiences, creating networks of new associations.
5. Influence What You Dream About
Beyond using the boundary states of sleep, you can influence dream content directly through pre-sleep suggestion. According to Jandial, simply stating an intention about what you want to dream about—aloud or mentally—nudges your dreams in that direction, particularly for problems with visual solutions. Focusing on a mental image of the desired subject while falling asleep also works because dreams are fundamentally visual. Your daytime mental life shapes your dreams as well: People who engage their imagination more during waking hours by daydreaming tend to have more vivid and creative dreams at night.
6. Gain Conscious Control Through Lucid Dreaming
The most advanced form of dream influence is lucid dreaming—becoming aware you’re dreaming while remaining asleep—which has been validated through experiments where participants signaled their awareness by moving their eyes in prearranged patterns while electrodes confirmed they remained asleep. Brain imaging shows that during lucid dreams, the Executive Network partially reactivates—specifically, the dorsolateral prefrontal cortex shows increased activity compared to ordinary dreaming. This gives you some awareness and potentially some control over the dream, though not complete conscious command. Scientists estimate that about one-third of people can learn to lucid dream with practice.
Jandial explains there are many methods for inducing lucid dreams. One of the most accessible is reality testing, which involves regularly asking yourself during the day whether you’re awake or dreaming, then testing indicators that differ between states. Examine your hands (which dreams often distort), try pushing your hand through solid objects, or check digital displays, which show incorrect or morphing information in dreams. Building this habit when you’re awake may trigger reality tests within dreams, revealing you’re dreaming and sparking lucidity.
Jandial also recommends the MILD technique (Mnemonic Induction of Lucid Dreams). This involves waking after five hours of sleep—which typically catches you just before your longest REM period of the night—then, before returning to sleep, repeatedly telling yourself “The next time I’m dreaming, I will remember that I’m dreaming.” This works best if you fall back asleep within five minutes, which enables you to return directly to REM sleep while the intention remains fresh in your mind.
7. Transform Your Nightmares
If you struggle with recurring nightmares, you can use your imagination to reshape them through Imagery Rehearsal Therapy. Jandial explains that this technique involves recalling the nightmare, rewriting the plot to make it pleasant instead of terrifying, and rehearsing your new version with vivid sensory details daily for several weeks. This works because nightmares are products of your imagination, and the same capacity that creates them can transform them. Research shows that this technique reduces both nightmare frequency and intensity. The success of Imagery Rehearsal Therapy reveals something fundamental: Since you create your own dreams, you can also reshape them through deliberate mental practice while awake.
8. Protect Your Dreams From Manipulation
While working with your own dreams offers benefits, Jandial warns that new technologies raise serious concerns about others manipulating your dreams without your consent. Researchers have developed algorithms that can identify dream images by matching brain activity patterns to reported content—essentially decoding what you’re dreaming based on brain scans. While current technology has limitations in speed and resolution, next-generation scanners will enable much more precise dream decoding. Along similar lines, companies are creating advertising campaigns designed to infiltrate dreams. For example, in 2021, the Molson Coors beer company created a campaign aimed at influencing Super Bowl viewers’ dreams.
Jandial recommends several protective steps: Sleep in environments without smart speakers. Keep phones away from your bed, as future user agreements for sleep-tracking devices might include clauses allowing companies to send quiet marketing messages during sleep. Avoid neurotechnologies with user agreements that grant companies control of your brain data. Support neural rights legislation—Chile became the first country in 2021 to amend its constitution to protect brain activity and information as a fundamental right. Be aware that the border between science fiction and current reality is narrower than you might think, and the technology to manipulate dreams already exists.
FAQ
What is This Is Why You Dream by Rahul Jandial about?
This Is Why You Dream explains why we dream and argues that dreams serve essential functions like emotional processing, creativity, and identity formation.
Do dreams only happen during REM sleep?
No. Research by Jandial highlights that dreaming can occur during any sleep stage.
Why do dreams feel so vivid and emotional?
During dreams, emotional and visual brain regions are highly active while logical reality-checking is turned down.
What parts of the brain are involved in dreaming?
Dreaming involves the Imagination Network, emotional centers like the limbic system, and reduced activity in the Executive Network.
Why does the brain invest so much energy in dreaming?
Jandial argues dreams provide survival benefits by keeping thinking flexible, processing emotions, and rehearsing scenarios.
Can dreams help with creativity and problem-solving?
Yes. With logical constraints lowered, dreams allow new connections and visual insights to emerge.
Do dreams play a role in shaping who we are?
According to Jandial, dreams contribute to self-understanding and identity, especially during development and life transitions.
