Do one thing every day that scares you.
—Eleanor Roosevelt
How many times have you asked yourself “What could go wrong?” before letting your mind spin out a dozen potential catastrophic failures?
I do this all the damn time.
Yes, I’ve spent the better part of my adult life working on myself—mind, body and spirit. I exercise. I do breathwork. I watch what I eat. When I go on assignment in an exotic, dangerous locale, I do my homework. I plan ahead. I minimize risk out the ying-yang. And still I wake up in the middle of the night wondering what I missed. There must be more I could do.
But there’s one irreducible truth to every human endeavor: Risk is risky. We can never iron out all the wrinkles in this life. Nothing is actually easy. Which has led me to this blanket conclusion:
How we resolve the tension between risk and reward defines who we are. And fear is a guidepost for how we use the Wedge. It is as much an involuntary response to a prediction of the future as it is a sensation that immobilizes our biology and stops us from taking action. Mastering fear doesn’t mean ignoring danger, but rather finding a reason that makes danger worth it—separating the stimulus from the response. More important, the way that our brain encodes fear gives insight into everything we sense, feel and react to.
About ten years ago, I was reporting a story from a jungle in central India about a war between the government and communist insurgents that had raged on almost since the country’s independence. A day earlier, child soldiers with automatic weapons and bows and arrows held me up at a roadblock, but now I was sitting across from an Indian colonel who informed me that he was planning a raid on an enemy encampment. It sounded like something I should be there for, so I asked if I could come along. He said yes, but advised me that there were certain risks I would have to be willing to take.
First, it would be a long hike over grueling terrain.
I was okay with that.
Second, the army wouldn’t be responsible for my safety when the shooting started.
That sounded a little dicey, but I figured I could stay far enough away from the bullets. Maybe I’d hide behind a tree.
Third, there would probably be land mines.
My heart dropped into my stomach. I started to sweat. My mind spun out a vision of the future where an errant footstep and explosion ripped off my legs and sent shrapnel through my guts. There would be an airlift, a mournful return home, and years of rehabilitation without prognosis for recovery. I felt queasy. Terrified. I didn’t know it before he said it: Bullets and exhaustion were one thing, but land mines were a bridge too far. I’d be happy to read a report about the raid later.
Over the years, I’ve done a lot of dangerous things. Maybe I’ve been lucky to escape with my skin intact. But how is it that I can look at one threatening situation with a shrug and then want to hide under my bed when the stakes change just a little bit? Some alchemy must happen at the neurological level that makes abstract ideas into things that I can feel in the pit of my stomach. I want to know what process my brain and nervous system go through to transform a sensation into a thought. Where’s the interface between neurology and experience? And how might I use fear as a wedge? I realize I am going to have to call in an expert.
A few years ago, I had a conversation with a neuroscientist at Stanford named Andrew Huberman who had set up a laboratory to study the complex neurology of fear. He was unlocking the mysteries of how our brain encodes sensation and visual stimuli as visceral emotional responses. More specifically, he was looking at how people responded to suddenly being face to face with great white sharks. What could be scarier, right? I called him up again and made plans to meet him at his Palo Alto laboratory. I had a gut feeling he could teach me a lot about about how my brain builds automatic assumptions about the world.
A few weeks later, we’re sitting in a trendy restaurant a few blocks from where Steve Jobs lived while building his Apple empire. The menu boasts enough salad bowl varieties to match any fad diet. As we crunch our lettuce and sip iced tea, I am struck that Huberman looks more like a mixed martial arts fighter than a neuroscientist: He’s tall, with dark hair and a rigid chin line, and muscles bulging through a Henry Rollins-esque black jacket. Tattoos cover most of his body below his neckline. I begin with the most basic question I can think of: “What is fear?”
Instead of answering directly, he breaks into a story about an experience he had a few weeks earlier while running one of his fear-based experiments. He knows he’s got a good yarn to spin, because this time his life was on the line.
He was about 40 miles off the coast of Mexico and 40 feet below the periwinkle surface of the ocean. Above him, a boat packed to the gunwales with state-of-the-art camera and diving gear was his laboratory on the sea. He was here to collect footage of some of the largest predators on the planet in order to reproduce them in a virtual-reality simulator back in his lab. But something was wrong, and it wasn’t just the great white sharks circling his cage. Andrew Huberman couldn’t breathe.
A long air tube called a hookah line snaked from the boat to the Stanford-based neuroscientist’s mouth. Somewhere along the way, it either kinked onto itself, or the pump that forced air through the tube stopped working. Either way, Huberman knew that he didn’t have much time; 40 seconds at the most. So he leaned back on his training, cleared his mind, and tried to think his way out of the situation before he ended up gulping down an ocean of water.
The shark cage was a rectangular steel box about five feet at the base and eight feet tall. At opposite corners of the cage, two backup tanks carried about ten minutes of air for emergencies like this. He reached down and put his mouth on the regulator of the first tank. Nothing. He tried the gray metal knob on one canister, but it refused to rotate, as if a pin was locking the mechanism. The other tank offered the same result. With no time to wonder why the backups weren’t working, he pushed off the metal floor and carried himself to the top, where he tried to shake the hose free. Still nothing. He drew on the tube again, but all that did was create a little reverse suction, pulling his tongue gently into the aperture. Things were starting to get scary.
Outside the box were at least six great white sharks between 10 and 17 feet long; some weighing as much as 3,000 pounds swam by. While the team knew about the nearby sharks, no one had an exact count on how many hid in the haze just out of range. Huberman locked his eyes on one ancient battle-scarred monster, his brain somehow recording the shark bites that marred its sandpaper skin as it swam toward him. A flick of its tail sent it careening past a diver who was bravely recording the encounters with a special 360-degree camera but had his back to the cage.
Twenty or 30 seconds had passed since Huberman’s last breath. The frothy sensation of panic began to well up in his gut, threatening to take him out of the moment and squander any hope of escape. While his life hung in limbo, the wrinkled face of his bulldog, Costello, filled his mind. It was a bit of a non sequitur, a brief interlude in the moment of high drama. But he remembers focusing on his pet and thinking, I’m going to make it back home to him.
Between thoughts of Costello and being ripped apart by sharks, he took a moment to assess his options. He had two: He could exit the top of the cage and make a sprint to the surface, or he could try to get the attention of one of the other divers, share their air and buy time. The second option was the best, but no one was looking in his direction. He wrapped his fingers around the hatch above him and tried to calculate his chances of escape. Getting to the surface might not be hard by itself, but the sharks made the errand more complex. Divers who remain calm attract less attention than those who panic. Rapid breathing, fast movements and the hidden signals that we all give off when we’re frightened can trigger a predator’s hunting response, which can transform an unappetizing neoprene-clad diver from a curiosity into prey. Dashing to the surface right then meant that Huberman would not only be fighting his urge to breathe, but possibly also racing away from a creature that can reach bursts of speed over 35 miles per hour.
Maybe I can go when they’re not looking, he thought. It was a risky move. If one of the great whites caught sight of him—a likely occurrence since they have panoramic vision—his last sensation could well be teeth ripping through his wetsuit. On the other hand, there weren’t many other options.
Huberman steeled himself for the rapid ascent, picturing the movements his fins and arms would have to make during the sprint. Then, by chance, his friend—who had spent 10 years organizing shark expeditions—followed the path of the battle-scared shark, passing him so that the cage entered his field of view. In a moment of brief communication, Huberman ran his finger across his throat—the signal for being out of air underwater. The dive organizer put his hands up in a shrug, as if to ask, “How is that possible?” Huberman symbolically cut his own throat again. Convinced of the emergency, the other diver swam over, removed his regulator and shared it with Huberman. Another 10 seconds and the situation could have ended in tragedy.
The two men slowly ascended to the surface together, making subtle deliberate movements until their heads broke the surface.
Once he was safe and in the boat, says Huberman, another friend of his on the expedition, a former Navy SEAL, gave him a wry grin.
“So what did you learn?” the friend asked.
I look across the table at him expectantly. “Yeah, what did you learn?”
And then Huberman answers my question.
At one level, he says, fear is a specific type of arousal in the brain stem characterized by the secretion of adrenaline, then discomfort and perhaps a dash of confusion. I can see that he thinks his first attempt at an answer is not quite good enough, so he tries again. “It’s the anxiety that you feel when you don’t know what behavior can remove a feeling of helplessness in the face of a threat.”
He’s obviously having trouble pinpointing such an obvious yet ephemeral concept. But he’s landing on the same interfaces of the Wedge: There’s external stress, a sensation he can feel in his body (anxiety), and an orientation to the threat.
He goes on to recount that it wouldn’t have helped him to spend time thinking about all the ways he might die. He was too busy to contemplate alternative endings. Instead, he had to remain calm and problem-solve his way out of the situation. “I still had options,” he says. Fear would have meant he was out of control. No choices. So maybe he wasn’t exactly afraid in the moment. It was something else.
Huberman decides to paraphrase the great horror writer Stephen King: Fear has a lot to do with time frames. Before the event, a person experiences the dread of anticipation; during the event, there’s terror when they’re helpless in the moment; and after it’s over, a person remembers the experience as horror.
In fact, if you can think back to any Stephen King book (or for that matter, anything in the horror genre), we experience fear more as anticipation than anything else. The build-up to a scary clown lurking in the sewers creates more emotional resonance than the actual moment it grabs you.
As I listen, my mind wanders back to my battlefield experience in India, and I realize that it was an entirely different type of fear than what Huberman went through. In the dread-terror-horror continuum, I felt dread as I anticipated the possibility of stepping on a land mine in India. But for Huberman, the danger was so immediate that actual fear didn’t have time to enter the picture. It’s only after the event that the story evokes something powerful: a sense of horror when we look back and anticipate what might have gone wrong. In both cases, however, the danger demanded a particular type of mental state to avoid fatal consequences, wedging open a space between stimulus and response. Maybe this is why some people enjoy the anticipation of dread that builds up in a horror movie. They’re in a safe space, but they identify with what they see on screen in a way that tickles their innate anxiety. For the record, I’ll tell you that I can’t even make it through the previews.
The entire reason that Huberman ended up in the waters of Guadalupe, off the coast of Mexico, in the first place was to capture footage of great white sharks with 360-degree cameras. Media engineers in his lab would be able to use the footage to re-create a virtual shark dive. Since most people have a visceral reaction to the ocean’s apex predators, Huberman hypothesized that the film could be a standard stimulus to study the biological underpinnings of fear. The virtuality-reality goggles his test subjects wear can track eye movements, dilation and blinking to reveal autonomic responses to whatever he puts in front of them.
And this, in short, is why Huberman’s research is so interesting. Fear is an excellent inflection point to demonstrate the physiology of the Wedge. It’s powerful, visceral, has a strong influence on our behavior, and yet also preserves our ability to make choices about our actions. We experience fear on both a biological and psychological level. It triggers the fight-or-flight response just as reliably as the cold does, issues a burst of adrenaline, secretes sweat, dilates pupils and ramps up the heart rate. However, with fear, our bodily reactions are based on sights, sounds and our own idiosyncratic assessment of how things are changing around us in a bad way. It starts in the mind, not the body. And this is why I hope that his research into fear can help me dissect every other emotional and environmental interface that contributes to the Wedge.
…
But before we go there, before we can hack our nervous systems, you should know a few things about how it works. The central nervous system is everything in the brain and spinal cord, while the peripheral nervous system encompasses every nerve bundle that reaches out into the rest of the body. The peripheral nervous system has two divisions: the somatic, which lets you direct muscles and sensory systems with conscious control; and the autonomic, the parts that regulate background body functions like digestion and heart rate without the need for thought. The autonomic nervous system itself has two main divisions: the sympathetic, which governs the fight-or-flight response; and the parasympathetic, which controls rest and digestion.1 When any part of the nervous system kicks into gear, it’s considered “aroused.”
Fleeing a predator will light up the entire sympathetic system at once. Sleep ignites the parasympathetic nerves. Flipping the switch between parasympathetic and sympathetic defines our “state.” Mastering the Wedge puts our thumb on that switch so that we can learn to control the state of our nervous systems, flipping between sympathetic and parasympathetic systems almost at will.
In some ways, you could say that all arousal states are created equal. Consider the example that I mentioned in the previous chapter: If a gazelle and a lion are on the open savanna, and suddenly the lion leaps out of hiding and starts a chase, both animals trigger the same sympathetic nervous pathways. Both animals fire the same hormonal cocktail into their bloodstream to give them a spike of energy. Their pupils open up into saucers and their pain thresholds deepen, and the only difference is that the lion is the only one that wants to be there.
If, for some reason, the gazelle falls down, then the few helpless seconds that it’s waiting for the lion to pounce are pure helpless terror. If, for some reason, the gazelle happens to get away—imagine the lion misses its pounce and falls off a cliff—then the memory of the terror that the gazelle felt will live on in its nervous system as horror and will flavor every encounter it has with lions in the future. That memory of fear gets hardwired into the animal’s physical anatomy. The experience lives in a neural memory circuits and goes on to influence future experiences. Now imagine that a person could choose what specific experiences become hardwired as a permanent neural circuit and which don’t. This is the Wedge.
The three main building blocks of human experience are time, emotion and sensation. The brain must account for all three factors in order to encode information from the outside world.
When the nerves first identify something—whether a visual stimulus like a shark swimming up from the deep-blue depths below, the feel of the ambient temperature and pressure of the water on the skin, or the sound of a respirator suddenly not working—the brain needs to make sense of the situation and come up with a plan of action.
Humans sense the world in two different processes: perception, or signals that come in from the outside world; and conception, or internal understandings that define the world from the inside. Neurologists call these two types of mental processing “bottom-up,” for perception, or “top-down,” for conception.
You can think about the nervous system as a collection of branching circuits, where each branch triggers subsequent parts of the network. Raw sensation enters through the nerves in the peripheral nervous system and branches off into two different channels: internal and external. Internal channels provide information about the state of the body—hunger, pain, overheating, etc.—and external channels deliver information about the state of the environment around the body.
Both processes only take a fraction of a second as nerve pathways fire and make sense of the environment, but a lot happens in that infinitesimally short period. Sensory information and cognitive processing take slightly different amounts of time to process, and as the brain organizes different streams of information, it creates a filter between experience and raw reality. This organizing process means that humans are always living in the past. And because of our peculiar anatomy, sometimes it’s a more distant past than you might expect.
Stimuli from the internal channel trigger two responses, starting in the lower areas of the brain stem. The first signals immediate physiological processes—digestion, heart rate, blood flow—without asking higher areas of the brain for any input. The reactions happen automatically; there’s nothing you can do to directly influence them. The second response occurs at an instinctual level. It is a sensation, like hunger, pain or cold, that prompts you to take action. These sensations can be strong, weak, or anything else that could fit on the volume knob of an amplifier; they don’t yet have a quality that the body can understand beyond a primal level. They’re effectively meaningless. But things get interesting once these signals travel to the next-higher brain area. Because while you can’t affect how they feel, you can control whether or not you want to respond to them.
The limbic system interfaces raw sensation with higher cognition. Some limbic structures you may have heard of, including the amygdala, the hippocampus, and maybe even the insular cortex; these regions serve as relay and processing centers where sensory information becomes experience. I like to think of the limbic system as a sort of library whose main role is to pair emotional values with sensations and then store those pairings for future reference.
When the limbic librarian receives a sensation, it checks its records to see if the nerves have sent along something similar before. If there’s no record, the librarian passes the sensation along to the paralimbic cortex—the center for emotions—to figure out how to categorize the new information. The paralimbic cortex pairs the new sensation with the brain’s current emotional state and creates what Muzik and Diwadkar call a “symbol.” Symbols are the books in the limbic library. Once it’s been created, a symbol is filed away in the brain stem by the limbic librarian. The next time the librarian encounters the same sensation, it won’t need to consult the paralimbic cortex again; it just pulls the old record (the symbol) off the shelf and passes it to the brain’s higher-functioning centers. And whether it’s relevant to the current situation or not, that old emotional value gets passed along, too. In effect, this means that every time you feel something you have felt before, you’re actually reliving part of your emotional past. This is the neural vocabulary that locks all animals together in emotion, time and sensation.
Neural symbols are the building blocks for all higher cognition. They are the bits and bytes at the center of all of our brain’s software, because without them, the sensations we bring in from the outside world wouldn’t actually mean anything; it would all just be data. The unique architecture of the brain means that everything we sense from the world carries an old emotional value along with it. Everything we experience is inherently a blend of objective data from our senses and the total subjectivity of our emotional state. And while this might not seem like the most efficient system, once we understand the architecture, then we have the opportunity to intentionally create our own new neural symbols to hack our biological software from the ground up. This is the physiological underpinning for how we experience the Wedge.
Because this is such an important concept, I’m going to explain it again by going back to the sharks. Initially, photons enter the eye, forming the sharp edges of a toothy sea creature. If you’ve never seen one before, the fish might be meaningless; you might associate it with warm, fuzzy feelings of weightlessness and underwater exploration. However, if you happened to have seen the film Jaws, then your brain could cross-reference the memory against the terror you felt imagining a giant shark chasing you on a family swim. In this case, the paralimbic system can identify the potential threat, cross-reference it with an earlier emotional state, and notify the sympathetic nervous system to kick into action. This process allows an animal to swim away from the threat, to play dead, or perhaps to stage a last-ditch fight to the death without spending a lot of time reasoning out the best course of action. The symbols are an emotional shorthand that allows for quicker action in the present moment—and as far as we can tell, it’s pretty much the same process for any mammal.
Our brains use symbols as the basic cognitive vocabulary that allows for long-term planning. On their own, symbols don’t hold a ton of information, but when you put enough of them together, they start to form complex thought. What we think of as “thinking” happens mostly in the cortical gray matter—in particular, those parts of the frontal lobe involved in planning and execution, such as the prefrontal cortex and areas within it that allow us to share a complicated language.
Without these structures, humans probably would not have evolved to become the apex predator on this planet. These higher brain areas allow the body to develop strategies around symbols that surpass the immediate ability for other animals to respond to the world around them. Instead of simply inscribing emotional reactions to a single stimulus, the cerebral cortex can pair symbols together in novel ways that build complexity, similar to the way that computers make billions of ones and zeroes turn into full-fledged programs.
The brain does this in part by using the grammar and syntax of neural symbols to account for the passage of time. It recalls symbols and recombines them so that they can anticipate what emotional state you might feel in the future. No matter how it reorganizes this data, all of these symbols start as sensations that first came up from the lower levels of the brain and peripheral nervous system. Without that data, the brain doesn’t have anything to process.
For instance, let’s imagine a young child reaching a hand up to the glowing coils of a hot stove. At first the pleasing orange glow and vague heat might draw on positive associations of warmth and spark a curiosity to learn more. However, contact with the coil triggers an immediate reflex to withdraw, followed by lots of tears. This entire experience creates a new symbol that the limbic librarian will file away for later: Glowing red tubes of light pair with the emotional pain of the injury. Now, a few months later, let’s say that same child sees a neon light with a glow similar to that of the electric coil. The limbic librarian might pull the symbol of the earlier experience off the shelf, note the emotion and surprise, and signal danger even where there is none. This only changes when the child creates a new association to neon lights. Over time, there are enough symbols in the library that the child can form a generalized understanding of the world informed by the combination of sensory and emotional information.
In this way, every shark image, business plan, mathematical formula, memory of a long-lost lover and decision to mull over whether to buy a luxury car or econobox sedan started as a sensation that bonded with an emotional value and then was processed in the higher brain areas. In other words, the brain never comes up with anything new on its own. Instead, it can only recycle old symbols that it already has stored and combine them in different ways.
This is why the Wedge is so powerful. If you can alter or bond new sensations to emotions, then you can insert a level of control directly into the fundamental grammar of your brain as you create new symbols. Instead of passively waiting for emotional states to bond with particular sensations, you can choose which emotions you want to hardwire into your nervous system. By giving yourself intense sensations at the same time you have a mindset of joy or determination or whatever else, you give the limbic librarian more symbols to draw from in future situations.
Here’s an example of how that might work. Let’s say you feel an aversion to public speaking. If you focus on your nervousness as your next speaking event draws close, you’re likely to go into a panic. However, if you instead focus on a fun or rewarding aspect of the experience as it draws near, then you can attempt to attach a different emotional value to it. If the event goes well, then the next time you have to speak in public will be even easier. You’ll have created a different neural symbol for public speaking.
Emotions and sensations are the building blocks of everything you experience. They’re so primal that it might not even be possible to have a thought without them. This is why extremely abstract ideas with little direct emotional or sensational resonance often fail to make an impression. If you want to make a convincing argument for just about anything, the best tactic usually relies on triggering visceral and emotional details rather than employing logic and abstract reasoning. In other words, I’m much more likely to capture your attention if I start a chapter of my book with an anecdote about a minefield in India or someone swimming with sharks than with a drab academic summary of neurological vocabulary.
Luckily, humans are pretty sophisticated, and our cerebral cortices allow layers and layers of neural symbols to come together to form bewilderingly complex thoughts. This despite the fact that no matter how logical we feel, emotions and sensations underpin the way that a person decides whether swimming with sharks is a good idea, ponders the cost of airfare, and ultimately decides to instead visit sharks in a comparatively safe virtual-reality simulator many miles from the coastline. I can thank my cerebral cortex for the ability to want a meeting with Huberman’s lab in the first place.
Still, actually planning that meeting required my brain to both recognize and organize symbols, and also an ability to keep track of time. And this is where things get tricky. Neuroscientists and lifelong meditators have long known that our minds slip from past to present to pondering the future, often without any obvious connection between reference points.
In moments of perfect focus or meditation, we might be able to experience the present. We simply put the limbic librarian to sleep and experience raw sensation. But those moments are few and far between. Usually our minds are all over the place—what Buddhists call the “monkey mind,” meaning that we are so easily distracted that our minds don’t have significant continuity from one moment to the next.
Monkey minds aren’t great for the modern world. Think about the million instances every day in which you should be fully engaged but aren’t. Perhaps it’s driving a car, where you are literally in control of several tons of metal speeding down a road along with hundreds of other high-velocity vehicles. The stakes are huge, and so, too, are the consequences if something goes wrong. Still, one ding on your cell phone and your attention drifts from the threat. Or maybe your brain wanders in emotional contexts. Perhaps you’re in the middle of having sex with your partner and your mind slips inexplicably to the work that you still have to complete tomorrow. Or maybe you’re taking a look over your finances—doing battle with the existential problems of the future—but can’t wait to get home to dinner. Visual information, physical sensations, memory and emotions all pull on our attention so that the human mind almost can’t help but wander, moving from one point in time to another with no apparent direction.
But as scattered as we are, we can actually focus; sometimes it comes naturally. While it might be impossible for me to pay attention to anything specific when I’m sitting at a cafe trying to write—I usually end up watching people for the duration of a cup of endless drip coffee—if I sit on my couch at home, I can devour a book in a single sitting. Focus requires the ability to shut out other stimuli and fix our attention to one place in time.
Focus lets us intentionally form and file symbols. With it, we temporarily hire the librarian to pull specific symbols from the paralimbic library and then escort them into the higher brain areas. Focus is a kind of wedge at the root of everything we do. It’s as easy as breathing. It allows us to take control of how we want to experience the world. However, we can’t focus all the time. Instead, we use focus to help give the limbic librarian new instructions for how to continue when we’re not paying attention.
While most of us maintain an illusion of continuity in our daily lives—a sort of story that we tell about ourselves that proceeds from our earlier memories until our last days on Earth—consciousness doesn’t experience all those moments at once. Most of the time we’re on autopilot.2 We make ourselves real by the amount of attention we’re able to summon.
This idea of focus is related to the way that we talk about mindfulness, which is popular today in self-help and spiritual literature. Huberman says that on one level, mindfulness is great, because focusing on the present moment and sensations cultivates a solid anchor for focus to flourish—but mindfulness alone isn’t enough. “If a person just experiences the present moment, then they won’t be able to plan for anything in the future or remember the past. Yes, in intensive meditation states, people can feel bliss and timelessness, but if you go too far in that direction, you don’t have any drive. You aren’t an actor in the world anymore,” he says.3 If you want to be a complete person, you need to know how to be in the moment, and how to connect those moments to other places, ideas and memories. And this is why we need the Wedge: because it forces us to focus on the connections between the environment, sensory system and conscious experience. When we consciously form new neural symbols, we aren’t just acting in the present moment; our choices and emotions right now also inform how we feel in the future.
…
With all of these thoughts buzzing around my mind in the cafe just a few blocks from Stanford, I have to wonder how it all connected to Huberman’s experiment with the sharks. How does the virtual shark footage unlock the mysteries of the brain?
To show me, we walk together toward his laboratory, past rooms full of impossibly expensive microscopes designed to help technicians dissect mouse brains, and small centrifuges that spin who-knows-what at incredibly high speeds. Huberman gestures to a half-dozen pictures of Costello the bulldog, as well as beautiful hand-drawn sketches of the optic nerve that hang on his wall. Then he leads me down an industrial hallway. The otherwise drab office door opens up to what at first looks a little like a recording studio.
The control room features a standard computer monitor and an undergraduate lab tech by the name of Troy Allen Norcross, who looks out of a bay window into an adjoining room fitted with gray padded walls. The tech looks on through a glass panel into the VR chamber. Each corner of the room features a motion-capture camera that records every movement that happens inside. A set of VR goggles dangles from a cable on the ceiling, and a small foam bat hangs on the back right wall. Norcross gives me a wand that I’ll use to interact with things in the new environment and acts as a proxy for my hands.
“It’s not a mental institution. We had to pad the walls because people kept walking into them,” he offers when I give the insulation a raised eyebrow. Huberman instructs me to sit in a rolling chair in the middle of the room and don the goggles. He then clamps two headphone speakers over my ears.
When the visor powers up, I find myself sitting in a digital reproduction of the room I was just in. The walls don’t quite have the reflective quality of the real world, but when I move my head left and right, the display compensates for the changes so that the virtual space feels real. Or at least about as real as a video game could ever possibly feel. I’m not wearing any sensors on my hands, feet or body; the computer can’t populate them into the visual field. So I’m really just a floating head hanging in a digital world. I also can’t feel anything that I see in terms of touch, smell, pressure or whatever else. But as long as I try to ignore those details, the setup almost feels, well, real.
Once I’m settled, Norcross fires up the first script of the day. At first the machine needs to calibrate itself to my own individual eye movements. A red dot bounces around the edges of the goggles, and I follow its path with my eyes. Sensors will record the way that my pupils dilate over the course of the experience. Those changes indicate how my autonomic nervous system responds to whatever scenarios they throw at me—giving away telltale signs of how my visual processing center detects threats. If, for instance, my pupil dilates when it perceives a barking dog in the virtual distance, it could be a physiological sign of a latent phobia and a signal that my sympathetic nervous system is firing too early—whereas a control group might not react at all.
The program starts, and I’m transported onto a boat deck somewhere off the coast of Mexico. I can see the gray outlines of sharks swimming after chum in the water below. The headphones relay the gentle rhythmic tapping from some sort of cable on an iron pole. There’s a cut in the scene as I go beneath the water in scuba gear. The respirator translates a passable Darth Vader impression through the headphones. As I swing my head left and right, I have a panoptic view of the school of virtual sharks from one of Huberman’s expeditions.
In this scenario, I’m supposedly part of a dive team with a group of fellow researchers. It feels a little like being in a movie where the film continues around in 360 degrees. At first the sharks lurk in the distance, where the gray-blue predators appear indifferent to the underwater film crew, but I look back to my left and catch a glimpse of a majestic toothy fish swimming toward me. Just as in a real undersea dive, the danger could come from anywhere. Unlike in the real world, however, I don’t have any control over where the script goes, only where I look. There’s also a safe word: If I feel panicked, I can tell the guy in the booth to stop the experience. Or I can just take off the goggles. So it requires a bit of imagination to gin up any real responses.
Over the next hour or so, Norcross puts me through three or four other simulations. There’s one for arachnophobes, where I play a tic-tac-toe type game on a wall with a virtual mallet while the simulation unleashes a tarantula-sized spider in my peripheral vision. I take a few swipes at the creature but never am able to squish it. In another, I play with a dog who pretends to attack me, but it’s wagging its tail the whole time—a clear indication that it’s enjoying itself and not about to take a chunk out of my leg. In a program for claustrophobics, I get stuck in an elevator with five or six graduate-student actors as they run through a script talking about how bunched up they feel.
In another scenario, I stand on a ledge a dozen or so floors above a virtual cityscape. The program urges me to step forward along a precipice, and I have to resist a sense of vertigo. When I cross a bridge between two buildings, the ground beneath me crumbles, and all of a sudden I’m plummeting downward. It actually feels like I’m falling. Or maybe a better way to put it is that it feels like I’m falling in a dream. There’s no rush of air or confusion as I accelerate down, but my heart starts beating faster and I’m a little dizzy. When I hit the ground, my knees buckle ever so slightly as they brace for the impact. For that second or two, simulated motion overrides all of the associations and sensations that were telling me I was safe. It must have accessed a symbol in my mind that was already there about the meaning of falling. It was an ever-so-brief window into what it feels like to lose control, and a taste of what some people with generalized anxiety try to avoid. And this is the closest I’ve felt to an actual sensation of fear in Huberman’s lab.
I’d come to his lab with the intention of getting a crash course in neuroscience to understand how the brain moves between stimulus and response. I’m using the tool that he designed to test and shed light on those questions. However, part of me wishes that the scenarios conjured stronger feelings. I’d hoped that he’d have a high-impact device that would make me tremble with anxiety so I would find tools to overcome fear in any scenario. Unfortunately, that’s not really the point.
Huberman had a very specific audience in mind for the simulator, and I’m not it. The program is really meant for people diagnosed with generalized anxiety disorder, whose brains have already encoded symbols that automatically trigger their fight-or-flight responses. For the virtual program to make them anxious, a patient has to be so primed for anxiety that merely the suggestion of a threat is enough to make them nervous.
To be clear, I am not immune to fear. But 20 years of taking on dangerous assignments, and nearly a decade of breathwork and cold exposure have, apparently, made me immune to virtual sharks. Instead, Huberman offers, I would make a really useful member of a group to establish low-anxiety baseline controls against his subjects.
For Huberman’s target patients, the VR simulations are direct conduits to their nervous systems. Their attention is so heightened to potential threats that their bodies don’t notice the lack of water pressure on their skin, the silly goggles or the padded room. Their eyes take in the visual information and their body screams “SHARK!” before their minds can catch up.
And if you think about it, these hundreds of patients in Huberman’s lab are heroes. Their bodies are primed for catastrophe, just as I would be if I were offered a chance to walk through a minefield. However, their nervous systems are so sensitive to fear that Huberman doesn’t need to use dangerous scenarios to measure their anxiety. And this is helpful for everyone. Because while fear is subjective, just as with the gazelle and the lion, the biological responses are the same for everyone.
Huberman’s lab is still refining the process. Looking for physiological measures of anxiety isn’t an absolute science...yet. There isn’t a single physical measurement that Huberman can point to that could stand in for a diagnosis from a psychologist. Instead, he homes in on changes in breathing and heart rate, pupil size and, in patients with electrodes in their brains, the way that their amygdala fires in response to the virtual environment. There’s so much data to access that he needs powerful computers and machine learning to suss out the patterns. And although he hasn’t published the results yet, he sees a signal in all that noise.
A more accurate method for visualizing which structures are involved inside the brain could have involved an MRI machine to track how different areas light up in real time. But since those machines require being perfectly still, it isn’t a practical option. Alternately, Huberman could have implanted sensors directly into my brain, but as he pointed out before the demonstration, “I would have had to involve the guys at neurosurgery, which, administratively speaking, would have been a pain. Also, we would have had to remove a section of your skull.”
So the next best thing is the virtual-reality tracker. In the simulator, potential threats appear at different distances to trigger predictable responses in the control subjects. By measuring thousands of people’s eye movements, Huberman has developed baselines for what a normal reaction is in the program and which markers point to pathological responses.
Again, these scenarios aren’t made to arouse people like me. In the Huberman Lab, they’re purely here to research the physiology and anxiety responses, but similar labs are starting to use VR to help people with phobias and anxiety. In cognitive behavioral therapy (CBT), therapists gently expose their patients to the things that make them anxious in order to relieve their symptoms over time. In a typical series of CBT sessions, the therapist gradually introduces the fear-inducing stimulus and then increases its intensity to build up tolerance. This could mean showing a snake-o-phobe a picture of a snake from across the room one day, a video of a snake on another, and then, much later, letting the patient hold a real snake.
Eventually—and if everything goes according to plan—the phobia goes away because the patient has been able to wire new neural symbols that override the terror that they initially encoded. The virtual room offers another step in that training process, as well as a controlled stimulus that the researchers can test and generalize across a population.
Anxiety disorders occur when autonomic systems bypass the mind and hijack the stress response. The emotions that created neural symbols in the first instance were so powerful, and tied together so tightly, that they hardwired stress into the patients’ systems. Exposure therapy in CBT is a way to access the Wedge. Patients control their anxiety in the face of something that stirs up their emotions, so that they can gradually desensitize their reactions. It’s often a slow process, and the key is that a person needs to feel something emotional in the presence of the stimulus.
However, people who don’t have anxiety disorders need stronger stimulation to trigger a useful sensory response to use the Wedge on.
But what if the stimulus were different? Whereas people with anxiety disorders are fighting their neurobiology just so they can function in the ordinary world, people without disorders might be able to learn to hijack their sympathetic responses by repeated exposure to what feels like a life-threatening situation. It should be possible to train away a panic response. If I were going to try this, I’d have to find something that scares me and provokes a sense of anxiety, then bond it with a positive emotion. The limbic librarian would take care of the rest.
A couple of weeks ago, Huberman inadvertently had a chance to test his own response to danger in a sea of great white sharks.
“It was a grim situation. In the best-case emergency scenario, you form a plan and work through a protocol to survive,” he says. This feels like the understatement of the century to me, but he’s a scientist, after all. “We all imagine that in a high-stress situation we’ll be deliberate. But reflexes are faster than higher cognition. When I reached down to an air canister and tried to breathe and instead swallowed a mouthful of water, I almost gagged. That would have been the end. But a strange thing happened. I couldn’t help it—I started thinking of my dog, Costello, and I knew that there was a time in the future that I would see him. It gave me a reference to think about. Now, who knows if that’s what saved my life—there was absolutely a lot of luck—but it’s one of my clearest memories of my escape: my dog’s face,” he says.
Huberman thinks that it’s possible that the image of his dog was his brain’s way of telling him that his life was worth living—and that his struggle for survival in this moment would have a reward in the end. The goal of the Wedge is to separate stimulus from response. There’s no more important time to do that than when your life is actually on the line. The memory of his dog might have helped keep him calm long enough for a solution to emerge. If that were the case, then maybe Costello was a symbol that allowed Huberman to focus his mind during the emergency. Perhaps the thought of his dog was what he needed to overcome brewing panic and gave him the crucial few seconds he needed. What is certain is that Huberman didn’t spend those moments underwater dwelling on failure. He didn’t freeze in terror and then suck down an ocean of water. Whatever happened in Huberman’s mind to keep him in the present moment is worth considering. That ability to respond to the danger around him let him not only survive the immediate threat, but, on a larger level, keep contributing to the superorganism of life itself. In this way, Huberman’s individual agency was also part of a larger whole.
And while it will take some time for me to really let that lesson sink in, for now I’m going to have to continue my quest to understand the Wedge in a new context. I need to find a stimulus with higher stakes that evokes a real sense of danger. It doesn’t have to be a minefield, a shark attack or a gunfight in India. But it can’t be something that I can just brush aside, either. I need something just dangerous enough to demand my attention and focus my mind and body together.
…
When I leave the Huberman Lab, there’s already a message on my phone from a friend of mine in the Bay Area, saying that he knows I don’t have much time, but there’s someone that I just have to meet. Over the previous few hours, I’d learned something about how the brain and nervous system encode sensations and emotions together. I now know that neural symbols are the underlying building blocks for everything that I think and experience. But I don’t have a new practice to put that knowledge into action. I want a technique that’s easy to learn but also triggers enough of a response that it keeps me attentive. The message from my friend baits the hook with a line designed to grab my attention: “He uses kettlebells to put people into instantaneous flow states.”
My eyes linger on the word “kettlebell,” and I sigh. A kettlebell: The sphere of iron eight inches in diameter with a horseshoe-shaped handle on top is a staple of gyms everywhere. I’ve always associated them with Russians with too-huge necks who forgo social encounters to pump iron. I can’t remember the last time I’ve been to a gym. I don’t much like weights. But I have a rule when I’m on reporting trips that either ends up getting me into trouble or landing me in unexpectedly enlightening situations: Unless something is likely to get me killed, I try to say yes to all opportunities that present themselves. Maybe this person will have some ideas about what I couldn’t find in Huberman’s lab. At least the word “flow” sounds promising.
1 There’s a glossary in the back of this book to help with the sometimes bewildering number of terms that come up when talking about human physiology.
2 So far in this chapter, I’ve written a lot about how our jumble of neural connections creates a unified and indivisible self. Unfortunately, that’s just a story that our brain likes to tell us. A series of experiments starting in the 1950s demonstrated that there is more than one you in your brain. The brain has two hemispheres connected by a thick bundle of nerves called the corpus callosum that transmits information back and forth. Each hemisphere has a full set of cognitive hardware for forming thoughts and generally controls all the sensory hardware for one side of the body. Each side gets an eye and an ear, but only the left hemisphere can control the language center.
Occasionally, people are born without a corpus callosum. Some have brain injuries that sever the connector. And a few epileptics have surgery that disconnects the two lobes of the brain. With the connecting nerves cut, researchers realized that it was possible to devise experiments that would allow them to communicate with just one lobe of the brain at a time. A typical test looked like this: The researcher would cover the eye associated with the left hemisphere and then show the person a picture of a bell. The patient would report that they couldn’t see anything. However, when the researcher asked that person to draw what they saw, the patient had no problem drawing an image of the bell on a piece of paper. This was because the uncovered eye attached to the opposite hemisphere still controlled the hand and could communicate independently. When the doctors removed the eye covering and asked the patient why they drew a bell, things only got stranger. Rather than be baffled by their own drawing, the patient instead invented an elaborate story about how they saw a bell on the way to the test center and must have simply doodled it on the paper.
So when confronted by a discrepancy that undermines the story we tell ourselves about a unified consciousness, the human brain would rather offer leaps of absurdity and even outright lies to convince us that we have only one consciousness in our heads.
Roger Sperry, who won a Nobel prize for his work on split brains, wrote, “Both the left and the right hemisphere may be conscious simultaneously in different, even in mutually conflicting, mental experiences that run along in parallel.”
Perhaps this is why it’s so difficult to shift our own perspective of self into larger or smaller contexts when thinking about the Wedge. Not only are we an ecosystem to the bacteria in our bodies, but also, apparently, an ecosystem of independent consciousnesses that all somehow co-exist in our physiology.
Still, I’m thankful for the story. I don’t know how I’d ever get anything done if my various competing consciousnesses started to disagree with one another. And that’s more than just a flippant sentiment. With consciousness as messy as the spaghetti plate of neurology in our heads, the only solid thing to hold on to is what we’re thinking and experiencing right now in the present.
3 See my earlier book The Enlightenment Trap for the sometimes-fatal consequences of extreme mindfulness.