Ever since I turned forty, I’ve forgotten how to sleep. That is, I can fall asleep with no trouble, but I have a lot of trouble staying that way. Instead I wake up in the middle of the night for no apparent reason. And when I say “wake up,” I mean that I WAKE UP, as Russell Hoban described it, “like a man trapped in a car going over a cliff.” My heart gives a spasmodic lurch and I’m instantly wide-eyed and alert, listening, muscles poised. It can take hours for my pulse to subside and my brain to admit that there’s really nothing much to worry about at the moment.
My husband is accustomed to these episodes, but I suspect they’re taking years off my life (not to mention that they irritate the cat, who allows me to sleep on her side of the bed). I know too that I make things worse on these nights by humoring my nervous system, lying there and mulling over everything that might have caused me to awaken in full-on berserker mode. There is nothing more fruitless than confronting your worst fears when you’re sleep-deprived and pumped full of surplus adrenaline, yet I do it anyway: I replay contentious office meetings, analyze dark alleys I might have to walk down in the future, and think of the perfect way to greet Dick Cheney if I ever meet him in person. (“Hiya, Dick,” with just the right amount of hesitation after the “hi” and just enough emphasis on “Dick” is what I usually settle on. Then I formulate a list of people who might post bail for me.)
Fun stuff, but not very soothing. Rather than inducing me to slip back off into dreamland, this kind of antagonistic thinking gets me even more riled up. It takes the erroneous chemical message that some glitch of physiology dumped into my bloodstream and converts it to rational thoughts. It leaves me with mental images that tend to heighten my sense of powerlessness and persecution. In short, when I lie in the dark and dread things, I’m allowing my limbic system to exploit and bully my rational mind. And I don’t like bullies.
Still, it’s not entirely my limbic system’s fault. The hindbrain, as the limbic system is sometimes called, consists of the hypothalmus, the amygdala, and quite a few other highly specialized but not especially well-understood parts of the brain. Together they control our physiological response to stress, stimulating or suppressing our hormones, regulating our heart rate, dilating our pupils and elevating our blood sugar levels. In a crisis, all these physiological changes increase our odds of survival by helping us fight, flee, or freeze. The limbic system keeps us alive in the most primal way imaginable, and it does so with very little input from the cognitive centers of the brain.
But, as I’ve learned, you can’t overindulge it. I spend way too much quality time with my limbic system. I don’t get into many dangerous situations requiring immediate fight or flight, but imagining catastrophe in minute detail is a hobby of mine. As hobbies go, this is slightly less destructive than heroin addiction but worse than say, karaoke, which I have seen cause considerable strain in other people’s marriages.
When your default thought patterns are a non-stop dress-rehearsal for disaster, you spend far more time fighting within yourself than you do addressing outside threats. Whether I’m awake or half-awake, I devote an excessive amount of mental energy to refighting old battles and gaming out potential ones. I bring dead conflicts back to life over and over again, even when there’s nothing more I can learn from them. I extrapolate about possible future conflicts out of sheer habit. I have to be very careful that I don’t skew my worldview in the process.
Because the hindbrain, while dependable in emergencies, isn’t very smart. So quite often my analytical, speculative musings about danger will fool it into thinking there’s an actual threat, and my body will start reacting to the crisis I’ve envisioned as if it were real: Elevated pulse, rapid breathing. And unfortunately the limbic system remembers physical stress responses whether they were warranted or not; it aggregates them and uses them to predict what might threaten us in the future. Which is probably why I wake up in the middle of the night as if I’m crouched in a foxhole on the Western Front: My mind and body are stuck in a feedback loop where hypothetical danger has been nurtured as an academic exercise, and is now mistakenly treated as the real thing. Both instincts are trying their best to keep me safe, but they’re actually making things worse.
It’s something I’m working on—I’ve found that it gets better when I spar regularly—but I know I’m not alone in feeling caught in the middle between my “thinking” and “reacting” brains. It’s a common problem in the peculiar environment we now live in.
Carmel, a social worker who trains at my dojo, gave me this explanation of how our limbic systems are supposed to keep us safe: If you live near tigers, you’ll quickly become attuned to environmental cues that signal the presence of tigers. You’ll be sensitive to growls, for example, and the color orange, and stealthy movements in the underbrush. Those cues will trigger immediate defensive responses—running, hiding, grabbing a torch. You won’t stop to think about these responses. They are instinctive, reflexive physical reactions to sensory information, and if you give them free rein they’ll keep you alive.
Problems can arise, Carmel noted, if you move somewhere new where there aren’t any tigers. When you get there, your limbic system is still wired to react to the old cues. You may know, in your rational brain—the one that bought the train ticket to the tiger-free neighborhood—that there are no more tigers in your vicinity. But your rational brain didn’t have the primary responsibility for keeping you alive when you lived with tigers. The neo-cortex is not a first responder. That burden fell to your hindbrain, the feeling and reacting brain. And that part of your brain doesn’t “know” that tigers are out of the picture now.
If you’ve experienced prolonged exposure to really hungry tigers—or if you’ve served in combat, or survived rape, or been traumatized as a child—your hindbrain may become hypersensitized to certain cues. Loud noises, specific locations, voices, words, and other stimuli can trigger a full-on stress reaction, even if the actual threat is no longer present. When people have extreme forms of this sensitivity, we call it post traumatic stress reaction. (Or sometimes “disorder,” but that isn’t strictly accurate. A hypersensitive limbic system isn’t out of order; it’s merely out of context).
My overactive hindbrain isn’t anywhere near as bad as PTSR; I’ve never (knock on wood) had anything particularly awful happen to me. Which I’m quite happy about, thank you. Yet I find myself imagining tigers everywhere. And what I’ve discovered in teaching self defense is that a lot of other women do too, in the form of stalkers, and rapists, and masked gunmen. All of which do exist in the real world, just as there are real tigers out there. But some of the women I’ve talked to, like me, spend extraordinary amounts of time and energy obsessing about these threats, given the odds that they’ll actually encounter any of them.
Why do we do this? I think it’s because there’s a new kind of threat in our modern environment that is much harder for us to recognize than a tiger: We live in a culture that uses fear to manipulate people, that exploits and abuses our survival instincts, and prevents them from working as they should.
In the normal course of events, a hypersensitive hindbrain can be rewired, though it learns to relax much more slowly than it learns to scream “Run!” It can’t think through problems rationally. It can’t take the cognitive shortcut of looking at a map and realizing “No tigers here.” Unlike our “thinking brain,” the limbic system requires experiential knowledge, repeated patterns of this-happens-then-that-happens: I see orange, but it’s only my neighbor’s marigolds, which don’t eat me. After trauma, the hindbrain usually regains an even keel if given time and space and a little peace and quiet.
Sometimes it’s more complicated—if there is physical injury to the brain, for example. But for most people, once they’re in a tiger-free environment and experiencing repeated cycles of seeing-orange-not-getting-eaten, the limbic response to the old triggers gradually cools down.
But look at the culture we live in. Like my hyperactive imagination, it throws potential dangers at us from every direction, nonstop, and spins them out into detailed narratives: Gruesome crimes are lovingly resurrected years after they were solved and turned into hour-long television shows. Missing white women dominate the news cycle for days. We’re hypersensitized to threats, via television, movies, news, advertisements, and office gossip. There’s no tiger-free region for us to move to, no way to escape from the danger. It’s a closed system, a feedback loop, and it’s very destructive.
What’s the result? People buy guns, and mace, and next-to-worthless home security systems, trying to calm their fears. They buy overpriced homes in gated communities, in the hope that a five-foot brick wall will protect them. They buy gasoline to drive themselves everywhere because they don’t feel safe walking. They spend money their rational minds could tell them they’re wasting, in an effort to appease their hopelessly duped limbic systems.
“Trust your instincts,” we tell people in self defense workshops. It’s good advice. But be careful too, about what you feed your instincts on. The hindbrain and the neo-cortex often come into conflict when we have to make complex choices about safety, and since the limbic system is in charge of our most basic survival instincts, it’s used to getting its way. Which is why the less scrupulous elements of our culture have learned to appeal to it. So it’s important, if we don’t want to be bullied and manipulated, that we keep our threat responses in proportion to the actual threats we face. We can discipline our fighting instinct in the sparring ring, or get out of the car and walk somewhere. We can look for reliable information about risk, or turn off the TV. And if we wake up in the middle of the night, we can do ourselves a favor by telling the hindbrain it’s off duty, and counting sheep instead of tigers.