Читать книгу The Fear Paradox - Frank Faranda - Страница 8
Оглавление“Could you be in a state of fear without feeling afraid?”
—Ralph Adolphs
A woman with the initials SM went to a hospital in Los Angeles one day because she was having blackouts. While there, she met a neuroscientist from USC by the name of Antonio Damasio. As he interviewed her, he noted something quite unusual: she reported that she had no fears and, in fact, had never been afraid once in her whole life.26 What Damasio and his colleagues learned was that SM, for all intents and purposes, was fearless.
SM, it turns out, has a rare condition known as Urbach-Wieth disease. The three primary symptoms of this condition are small pimple-like bumps near the eyes, a hoarse voice, and, most importantly, calcification in select areas of the brain, particularly near the amygdala. What made SM unique to researchers was that, in her case, the calcification that occurs with this condition had completely consumed the amygdala on both sides. Basically, Damasio was face-to-face with a woman who had no amygdala.
No bigger than an almond, the amygdala is located on both sides of the brain. Although the amygdala’s specific functioning is debated by neuroscientists, it has been identified in a great deal of research as central to the experience of fear.27 SM’s case gave Damasio a rare opportunity to witness, through its very absence, the amygdala’s role in fear. In turn, this case gives us a unique glimpse into what it would be like to live without fear.
SM has an innocent and trusting nature that often gets her into trouble. When the researchers brought SM to an exotic pet store, she was immediately drawn to snakes and spiders without any hesitation. She wanted to hold them and even touched the tongue of a snake. Though great for working with exotic pets, SM’s lack of fear has significantly impacted her quality of life.
A number of years ago, SM was assaulted while crossing a dark field at night in a neighborhood known to be frequented by criminals. Yet, even after the assault in that field, the next day, she walked right back through it again. SM is also prone to engaging with strangers, regardless of observable danger signals. Once, in a vacant park at night, she was held up at knifepoint by someone who seemed perfectly safe to her. SM continued to trust men who in the past had harmed her physically, and she still had no sense of apprehension when presented with the possibility of becoming involved again with these dangerous men.
SM is indeed fearless—but, clearly, this is not what we are after when we wish to be free of the limiting effects of fear. SM walks straight into situations that put her life at risk. Without fear, our survival would be difficult to maintain. Whether we like to admit it or not, being scared is sometimes the smartest thing to be.
But what is it that determines whether fear will serve us or betray us? Are there different needs that we have as human beings that determine the value of fear? Is there such a thing as good fear or bad fear? And most importantly, is our distrust of this protective emotion misplaced?
As a start to answering these questions, I would like us to look a bit deeper into a further piece of research SM agreed to participate in.28 Up to this point, SM had been taken to haunted houses, shown frightening films, and exposed to dangerous animals, all without any activation of fear. This time, however, researchers slowly changed the ratio of oxygen to CO2 in the air she was breathing in the lab room, an experiment known as the 35 percent CO2 inhalation challenge. Within minutes, something began to happen for SM, something she had never felt before. SM began to experience fear.
What this fascinating finding reveals is that SM’s lack of fear is not a result of her lacking the ability to feel the emotion of fear. SM doesn’t feel fear because nothing is telling her to feel fear. Somehow, in the CO2 experiment, something did tell her to feel fear.
The CO2 experimental design is often used by researchers in the study of panic. It is a surefire way to induce a strong panic/fear response. What was unique about this experiment, compared to other experiments SM participated in, is that the danger was internal, not external. And this internal signaling of danger was working just fine in SM—even without an amygdala.
Prior experiments for SM were focused through her senses, particularly vision and hearing. This experiment involved a more direct, internal, bodily perception of danger. The monitoring of internal systems of physiological regulation is referred to as “interoception.” Evidently, this physiological and neural machinery was working just fine for SM. The neural “module” that actually produces fear was also working fine. SM’s case has helped us begin to differentiate the fear response from the neural machinery that interprets sensory information and monitors for threat, the latter being dependent upon the amygdala.
In the initial experiments with SM, sensory information regarding potential threats traveled from her senses through the corresponding cortical areas, and then on through the amygdala to the midbrain and the motor cortices where aversive actions are initiated. Through this neural pathway, the data are assessed for risk and the appropriate behaviors are initiated: freezing when threats are distant, running when threats are imminent, and fighting when threats are upon us. In the CO2 experiment, however, the data regarding potential threats does not enter the senses to be processed by the higher cortical regions. Instead, this interoceptive data has a kind of hotline that directly triggers the midbrain motoric panic response.
There’s a startling lesson here: while the amygdala is critical to fear conditioning and threat detection, it is not the ultimate source of the emotion of fear. Joseph LeDoux championed the amygdala’s role in the “experience” of fear,29 but, according to researchers such as Jaak Panksepp and Lucy Bivens,30 he fails to give adequate weight to the midbrain’s involvement in the experience of fear. This deeper source for fear is supported not only by the CO2 experiment, but also by “awake brain surgeries” in which a surgeon directs an electrical stimulation to the midbrain and, with this, the surgical patient has a physiological and cognitive experience of fear.
The significance of this is twofold. First, the fact that fear activation occurs deeper within the brain explains some of why fear is so problematic for us. We literally have less neural access to the regions of the brain that generate fear. These deeper fear centers were online for us long before we evolved into Homo sapiens. Consciousness, as we will explore more in Chapters Three and Four, is a relatively recent addition, and as of yet, it has not found a way to control fear’s effect on us.
The second important element we can glean from this most recent research with SM is that the emotion of fear is not the only ingredient in the human recipe for security.
When Fear Isn’t Enough
I’m not one of those people who tend to remember lines from poetry or fiction, but a few lines from the novel The Information, by Martin Amis, have always remained with me. The narrator is describing his protagonist Richard rising from bed in the morning. Richard, as we are about to learn, is not doing well emotionally.
The narrator describes how he wakes up that day: “He woke at six, as usual. He needed no alarm clock. He was already comprehensively alarmed.”31
As these lines came into my head one recent morning, I wondered why. What was my mind working on? Did it have relevance for me or just for my book? I remember when I first read the lines, chuckling at their cleverness—like a good clue to the Sunday crossword. But something beyond the cleverness of these lines seemed to be at work. There was something meaningful about what it means to be alarmed in relation to what it means to be afraid.
Being afraid is more than just the emotion of fear. For its part, fear has a whole repertoire of things it can do. It can cause us to focus our attention, remain motionless, run like hell, fight for our lives, or just withdraw slightly from life. These defensive responses are called action tendencies, and every emotion contains a unique blend of them.32 But we first need to be aware that the activation of the emotion called fear, including these defensive behaviors, is only as good as the system that is detecting and interpreting what is uniquely dangerous to us.
Systems of animal security, in the simplest terms, are built around a capacity to detect threat and initiate defensive behaviors. Each species has evolved unique capacities for detection and response to danger, as well as innate fears that prime the system to what could be dangerous. An example of this is seen in the algae octopus. It may surprise you to learn that males have one arm that is significantly longer than the others. This arm, it turns out, is the equivalent to a penis that they insert into the female to deposit their sperm. The arm is long because the female of the species has an inconvenient tendency to strangle and eventually eat the male after he has finished depositing the sperm. The arm’s length gives the male a little advantage in getting away from love’s embrace.
Evidently, this cannibalistic strategy has proven successful for the overall survival of the species. The adaptation of providing the male with distance via his long arm, although paradoxical, seems to improve the octopi’s reproductive functioning and balance within the ecosystem—for, while it is true that the female benefits from the additional nourishment required for gestation, most likely the species would not benefit if every male were caught and eaten with each act of insemination. Males come into the world primed to be cautious of the female during mating; the extension of the arm, along with that innate caution, seems to give the males enough of a head start.
Innate fears and physiological adaptations develop in animals over eons. These fears are perhaps the most vital element in the maintenance of animal security. They correspond to expected dangers and reduce dependence on the vagaries of learning through experience. It is much easier to come into the world knowing what is dangerous than having to experiment or wait for guidance.
Another unique example of species-specific threat detection is found in rats. We all assume that rats and mice come into the world fearing cats. But in actuality, rats and mice only innately fear the smell of cats. If you visually present a cat to a juvenile rat that has never learned what a cat looks like, it will not have a fear response. However, if you put a cloth that is saturated with cat odor into a cage with that same novice juvenile, it will innately have a fear response and attempt to get away from that smell.33
As strange as this may seem, this adaptation makes a great deal of sense. Fearing the smell of cats innately will keep a rat or mouse from entering or remaining in a space that a cat has recently frequented. Avoidance of cat territory is more supportive of survival than innate fear of the sight of a cat. For, as we know, cats are very attracted to little mice on the run, and it only takes one accidental meeting for it to be too late. Between rats and cats, there is very little room for safe experimentation.
For most mammals, as we mentioned, security is maintained through a complex neural and behavioral experience in which a threat is perceived and defensive behaviors are initiated.34 The first step in this process of maintaining security is the perception of danger. Information is continually being fed into the brain; if and when something threatening is perceived, activation of fear occurs. This security equation is similar to the equation that operates security systems in homes and businesses. We usually only become aware of these security systems when we hear an alarm go off. But beneath any alarm is a system that monitors the environment for certain specific changes that are deemed worthy of an alarm response. The effectiveness of any security system lies in the precision and accuracy of this monitoring system. We need to be assured, if we are monitoring for fire, for example, that our system knows what to look for and is sensitive enough to trigger an appropriate alarm response.
In terms of human security, our brains have the capacity to differentiate between different kinds of threat and to initiate unique responses specific to the threat that is perceived. For instance, if you see your child about to run into traffic, you might have a very different fear response than you would if you were walking down an unfamiliar dark street at night. The same emotion, fear, is capable of eliciting different security responses.35 Even the fear response that causes freezing, one of the primary means of maintaining security, has subtle variations depending on the circumstances. An attentional freeze is designed to exact a razor-sharp focus for a distant threat, while a hiding freeze allows the nervous system to quiet and prepare to run again. One might even include in this list the “submission” response of tonic immobility that we explored in the last chapter, in which our non-conscious brains can shut down the entire nervous system in order to survive.
What does all this mean to us? First, we need to broaden our understanding of human security. The emotion of fear is merely the alarm that triggers defensive behaviors. But this emotion needs something to activate it. Under most circumstances, our sensory perceptual systems determine the threshold for activating fear. And, as we saw with SM, without a functional pathway to the fear centers of the brain, the emotion of fear will fail to be activated. But reduced activation such as this is not what troubles us most about fear.
No one would argue, I imagine, with the logic of desperately trying to outrun a tornado or escape from physical harm when threatened with a baseball bat. Those signals of danger are highly appropriate and worthy of the activation of fear. But the fear that is activated in obvious situations of danger is much the same fear as that activated in situations that our rational minds might deem relatively safe. A fear response that wisely keeps us from confronting a rude drunk in a bar can also keep us from applying for a job that we are well-qualified for. Although these fears are qualitatively and quantitatively different, the emotion is fundamentally the same. In each of these situations, something we perceive is processed in relation to our past experience. Signals are sent to the fear centers of the brain, and one of many types of fear response is initiated. This could be a vague sense of dread or an active attempt to flee.
How is it that benign or even beneficial situations come to trigger a fear response? What happens in our brains and minds to create such an unreliable system of threat assessment? Shouldn’t something as important as our security have a system that is rational and reliable?
Finding answers to these intriguing questions, as we will see, will not only help us understand the peculiarities of human security, but also lead us to a deeper wondering about the very foundations of our humanity.
Note: From this point forward, when referring to the comprehensive security system of threat perception, emotion, cognition, and aversive behavior, I will use the word “Fear” in capitalized form. If I am referring to just the emotion, I will use the word “fear” in lowercase form.
