Episodes 54 & 55 Shownotes - Science of Fear - Understanding our Brains
You are listening to best life after cancer, episode number 54. Today we are talking about the science of fear and also something I just learned about, but made SO MUCH sense why people struggle to change their thoughts after cancer.
But first, I am going to tell you a little story from when I was a kid. We lived out in the country with a stream about a quarter of a mile behind our house. There were no other kids for miles. so my brother and I hung out a lot, even though he was 6 years younger than me. At the end of a long winter, there was a day that was that perfect, really warm and beautiful spring day. My brother and I were outside and headed to the stream. We had spend time when things were frozen making a tree bridge across it. We got down to the stream and onto the logs. I was in the middle, with him right behind me, when I realized there were 3 snakes coiled up at the end of the logs in the sun - likely just emerging from where they had hibernated in the mud. Another snake was down near the stream under us. My brother was pushing me from behind, because I had suddenly stopped. I was so terrified, I couldn't even move. I managed to gasp out what was happening, and we backed off the logs. I started screaming and running for home. My brother, of course, was freaked out and running behind me, but I thought the swishing in the long grass and weeds was the snakes chasing me. I screamed louder and ran faster. That is when I remember becoming terrified of snakes. Every event involving snakes after that was a pathway faster than the speed of light. I saw a snake, and I freaked out. This bypassed thought, straight to a pounding heart, sweating and literally jumping onto whatever I could to get away from the snake, be it furniture, or another human. The interactions with snakes as the years passed - man, you would have thought one jumped up and bit me on the cheek, injecting me with the deadliest of poisons. I didn't need a reason to be afraid, I just WAS. When one swam out of the filter in our pool at home - I freaking walked on water to get away as quick as I could. When my kids (3 and 4 at the time) caught a garter snake in the back yard, I ran around the house and locked all the doors and left them outside with the snake. I'll pause here to tell you - they thought this was the funniest thing ever - they stood banging on the glass door with the little snake clutched in a chubby, dirty hand, beaming like angels. And when we were snorkeling in Thailand, I saw an unusual eel hunting on the bottom, and swam along above it, watching its unusual behavior. For some reason, I am not afraid of eels. Until this eel left the bottom and started up towards me and I realized it was a poisonous sea snake. Swimming towards my unprotected stomach. I started screaming into my snorkel and thrashing around like a woman possessed. I swear, the snake looked surprised, then worried, then decided to surface somewhere else. There was no rational reason I was so afraid. I had never been bitten, or even actually stepped on a snake. But my brain recognized a snake, and sent a huge jolt through my sympathetic nervous system, leading to all of the sensations that go with this - pounding heart, sweating, a surge of adrenalin.
So let’s talk about fear. One of the interesting things about fear is that we are born with only two innate fears: the fear of falling and the fear of loud sounds. A 1960 study evaluated depth perception among 6- to14-month-old infants, as well as young animals. Researchers placed the subjects on a platform that had plexiglass just beyond its edge to it to see how many of the subjects would actually step over the “visual cliff.” Most of the subjects – both children and animals – didn’t go “over” and step out on to the plexiglass. The fear of falling is an instinct necessary for the survival of many species. When you hear loud sounds, you most likely will react involuntarily. This is called the acoustic startle reflex. If a sound is loud enough, you will likely respond by ducking down head. What this means is that most fear is learned. Spiders, snakes, the dark – these are called natural fears, developed at a young age, influenced by our environment and culture. A young child isn’t automatically scared of spiders, but builds on cues from his parents. You get evidence from your parents and your environment that you need to be scared of these things. It is interesting to point out, though, while the fear itself is learned, humans seem to be predisposed to fear certain things like spiders and snakes because of evolution. Back in our ancestral age … young children learned not to pick up snakes and spiders because they could be venomous. Fear’s essential role in survival helps explain why it sometimes seems a little trigger-happy. In other words, it makes sense to be a little jumpy if you’re an animal in a hostile environment. It’s better to run and hide when your own shadow catches you by surprise than to presume that a shadow is safe, only to be eaten by a bear 5 seconds later. As we get older, fears are developed because of association. Norrholm, a neuroscientist, compares it to a soldier who survives an encounter with a bomb that was hidden in a shopping bag. If that soldier is redeployed and sees another shopping bag, he has a fight or flight response. Here, an association has been made between the cue and the fear outcome.
Let me take a minute to explain how our brain works. The brains of all animals respond to danger. Fear is a chain reaction in the brain that happens when you encounter a potentially harmful stimulus. For example, if you see a snake while hiking, there are two roadways for your brain, said Norrholm, a neuroscientist. First is the instinctive path that represents your brains sensory systems. What you see, smell, hear signals to the brain that this is something to fear. This is the “low road”. A small area of the brain called the Amygdala sends a distress signal to the hypothalamus. This part of the brain is the control center, and it communicates with the rest of the body by way of the autonomic nervous system. The connection between the hypothalamus and the body has two parts - the sympathetic nervous system, which is the gas pedal ramping everything up, and the parasympathetic system, with is like the brake, slowing everything down. It also activates the pituitary gland, which is where the nervous system meets the endocrine (hormone) system, which we will talk about more in a few minutes. During fear, the hypothalamus sends impulses to many different parts of the body to trigger a fight‐or‐flight response. This signaling prompts many body systems to undergo changes to give your body a burst of energy needed to defend yourself or escape a potentially harmful situation. Fight‐or‐flight responses are unlearned reactions that humans and many other animals automatically make to increase their chances for survival in a potentially dangerous situation. Organisms that feared the right things and made a fight‐or‐flight response were more likely to survive and pass on their genes to their offspring. During the fight‐or‐flight response, many body systems undergo changes to give your body a burst of energy and the strength needed to defend yourself or to run away from a dangerous situation. Both fight and flight require food and oxygen to provide the energy for vigorous muscle activity. What happens in the body when this system activates? Breathing and heart rate increase, peripheral blood vessels (in the skin, for instance) constrict, central blood vessels around vital organs dilate to flood them with oxygen and nutrients, and muscles are pumped with blood, ready to react. Muscles — including those at the base of each hair — also become tighter, causing the hairs to stand up, goosebumps in humans. When a human’s hair stands on end, it doesn’t make much of a difference to their appearance, but for furry animals, it makes them seem larger and more formidable. The sympathetic nervous system also inhibits, or shuts down, parts of the body that are not immediately essential for fighting or running, such as the digestive system, the immune system, the urinary system, and the reproductive system.
At the same time, our hormones of fear also kick in. The other way to get messages to many different parts of the body is through hormones secreted by the endocrine system. The pituitary gland stimulates the adrenal gland. This is an endocrine gland located near the kidneys that produces two fear hormones—adrenaline and cortisol. These hormones are carried in the bloodstream to all parts of your body. The effect of adrenaline, also called epinephrine, is similar to the effect of the sympathetic nerve action. These hormones can boost activity in the heart and lungs; reduce activity in the stomach and intestines, which explains the feeling of “butterflies” in the stomach; inhibit the production of tears and salivation, explaining the dry mouth that comes with a fright; dilate the pupils; and produce tunnel vision and reduce hearing. Fear hormones result in a longer lasting and more widespread fight‐or‐flight response than the effects of the sympathetic nervous system. Cortisol increases blood sugar level by converting stored glycogen and fats into glucose and suppresses the immune response. Fear hormones explains why you may feel the fight‐or‐ flight response even after you realize there really is no danger.
Normally, almost simultaneously, with the low road path, there’s a high road that goes through the higher cortical center in your brain. The high road says ‘I’ve seen this kind of snake before, and I don’t have to worry’. In this way, a reasoning response can override the low road. This involves the hippocampus, a brain region dedicated to memory storage, to help control the fear response. Along with the prefrontal cortex, which is part of the brain involved in high-level decision-making, these centers assess the threat. They help us understand whether our fear response is real and justified, or whether we might have overreacted somewhat. If the hippocampus and prefrontal cortex decide that the fear response is exaggerated, they can dial it back and dampen the amygdala’s activity. This partly explains why people enjoy watching scary movies; their sensible “thinking brain” can overpower the primal parts of the brain’s automated fear response. We will talk about this a bit more later.
Sometimes though, our fears evolve into a phobia that short circuits the high road. Over the years, I attributed a thought to this process - I hate snakes. But here is the thing - I talk often about changing thoughts, but the truth is, when we have a trauma response to something, we SKIP THE THOUGHT and go straight to those feelings of terror in our bodies. I could think all I wanted that snakes are part of the ecosystem, they are NOT slimy, they are more afraid of me than I am of them, but none of that matters if we bypass the thought and go directly to a fight or flight response. I had known this for years, but I was listening to an awesome class by Simone Seol and she pointed out that this trauma response may drive how we respond to things. I had a lightbulb moment. Oh - so some of my people can't stop this loop, because they are bypassing the thoughts and going straight to a fear response! So, when you go for a test, and they tell you after the doctor wants to see you. If you feel a sensation like what you felt when you were first diagnosed, and your brain goes straight to terror that the cancer is back. When you hear that someone famous just died from the cancer you have. You may be skipping the thought and going straight to a gut-wrenching fear. In psychiatry, phobias are classified as an anxiety disorder. They are often an irrational and overactive fear of something that may not cause harm. They can attach to pretty much anything and significantly impact people’s lives. There is no hard and fast reason why a phobia will develop; both genes and the environment can be involved. Sometimes, the origin can be relatively easy to understand: someone who witnesses someone falling off a bridge might later develop a phobia of bridges. In general, though, a phobia’s origins are tricky to unravel — after all, most people who witness someone falling off a bridge do not develop a phobia of bridges, so there is more to it than simple experience. While not completely understood, scientists have uncovered some of the brain pathways that trigger phobias. Given our understanding of the amygdala’s involvement in the fear response, it is unsurprising that phobias are linked to heightened activity in this region. One study discovered that there was a disconnect between the amygdala and the prefrontal cortex, which normally helps an individual override or minimize the fear response. Aside from the fear felt when someone with a phobia meets their nemesis, these individuals are also in a heightened state of arousal; they always expect to see their trigger, even in situations where it is not particularly likely to appear. Another study explored this phenomenon in people with arachnophobia, or fear of spiders. It found that if scientists told these individuals that they might encounter a spider, activity in their brains differed from control participants without a phobia. Activity in the parts of the upper brain, including the lateral prefrontal cortex, precuneus, and visual cortex was comparatively lower. These brain regions are key for the regulation of emotions; they help keep us level-headed. A reduction in their activity suggests a reduced ability to keep a lid on fearful emotions. Often, an individual with a phobia will be well aware that their response to the object that they fear is irrational. The weaker activity in these brain areas helps explain why this might be; the parts of the brain responsible for keeping a cool head and assessing the situation are muted, thereby allowing more emotional regions to play their hand.
This, I think, is one possible reason why some people may have such challenges changing their thoughts. When you have this response, FIRST, you need to take time to calm your body. The quickest, easiest and honestly, most effective, is pausing, and taking 3 deep, calming breaths with your eyes closed. In through the nose, and out through the mouth. That will start to activate the parasympathetic nervous system that puts the brakes on the instinctual fear response. Other things that work a short pause to meditate, rubbing or patting your arms, or a technique called tapping. Once you have calmed your instinctual response, you will be more able to get to the higher brain functions. I have realized that with a snake, I can’t stop the huge jump and racing heart, but I can pause in the moment, take a breath and not run and scream (unless a dear child is chasing me with a snake, which happens occasionally, with them laughing manically).
I want to get into WHY it is so important to recognize this instinctual pathway and try to overcome it. Our bodies cannot maintain a prolonged fight‐or‐ flight response. After an individual has fought or fled a dangerous situation, their body needs to shut down the fight‐or‐flight response and return to normal. The reversal of the fight‐or‐flight response, as mentioned, is caused by the actions of the parasympathetic nervous system. The parasympathetic nervous system consists of branching nerves that carry nerve impulses to many parts of the body. It causes the body to restore homeostasis or a balanced state, by relaxing and restoring basic life processes needed for maintaining health. Modern daily life, and life after cancer, can involve many stimuli that are perceived as threatening. Problems at work or at school, money or social problems, and cancer imaging or appointments, new pains or symptoms, hearing that someone else was diagnosed or died, can trigger a chronic or longterm fight‐ or‐flight response. Even anticipating or worrying about the possibility of a recurrence in the future can trigger the same response as actually experiencing it. Chronic stress occurs when the fight‐or‐flight response does not shut down to allow for the proper balance between fear and relaxation. Stress can increase risk of health problems. The fight‐or‐flight response uses calories so the urge to eat makes sense after running away or fighting. But, eating in response to daily stresses can lead to weight gain. When the fight‐or‐flight response causes blood pressure and heart rate to remain high, it puts extra strain on blood vessel walls. As a result, the linings of blood vessels can become damaged. This can lead to clotting at places of damage, and ultimately, interruption of blood flow to the heart and a heart attack. Blood vessels in the brain can also be damaged and blocked, resulting in strokes. People suffering from stress secrete cortisol at much higher rates than normal people. Increased cortisol levels cause elevated blood sugar levels that can lead to both weight gain and diabetes. There is evidence that abnormally high cortisol levels may also be the initial trigger for depression in some individuals. High cortisol levels result in sleep deprivation. Stress hormones also affects the function of the immune system. Stressed individuals produce lower levels of antibodies when exposed to pathogens. They also produce higher levels of cytokines, or inflammation triggering chemicals. Excessive inflammation is thought to increase the risks for heart disease, diabetes, and some forms of cancer.
Now is as good of a time as any to tell you something really interesting about fear. Fear is contagious. We know this instinctively, right? In 1998 at a high school in Tennessee, a teacher complained of a pungent “gasoline-like” smell in her classroom. Soon after, she fell ill, reporting symptoms such as nausea, shortness of breath, dizziness and a headache. Almost immediately several students in her class started to experience similar symptoms and, before long, the rest of the school was stricken.
The building was evacuated as Fire fighters, ambulances and police arrived on the scene to tend to the sick. That evening the local emergency room admitted 80 students and 19 staff members; 38 were hospitalised overnight.
But what was the mysterious toxic gas that sparked the outbreak? Several extensive investigations by Government agencies found nothing. Blood tests showed no signs of any harmful compounds. Instead, according to Timothy Jones a local epidemiologist, the fear of being poisoned had spread, fuelling the symptoms experienced by everyone inside.
A report in the New England Journal of Medicine attributed the outbreak to a phenomenon known as ‘mass psychogenic illness’, which occurs when the fear of infection spreads just as virulently as the disease itself. The students and staff had decided that, based on the behaviour of those around them, there was a real threat they needed to be afraid of.
The ‘outbreak’ in Tennessee demonstrates that people can be scared – to the point of sickness – without there actually being any real threat present. However, it begs the obvious question, what makes us feel afraid?
“There is some evidence to suggest that thrill-seeking is like anything pleasurable – gambling, eating, – it releases dopamine,” said Norrholm. Dopamine is a neurotransmitter that helps control our brain’s reward and pleasure centers. “We know that the more you reward something, the more that they do it,” said Norrholm.
And the more that thrill-seekers seek out the dangerous behavior, the better they are able to engage the cortical high road, and provide the rational context that the thrill-seeking behavior isn’t dangerous. Extreme sports athletes are a great example of this: They continue their dangerous behavior because each time they do it, they survive, Norrholm said.
There are some people who genuinely seem to enjoy being scared. “We know there are some basic individual differences in how people are wired,” said Glenn Sparks, a communications professor at Purdue University. Sparks specializes in the cognitive and emotional impact of the media, particularly horror movies.
“Some people are wired to seek out highly sensational experiences.” When they are exposed to that kind of experience “they get the adrenaline rush,” said Sparks. He likens those who enjoy watching horror movies to people who like riding roller coasters.
And Sparks says thrill seeking seems to have a gender bias. “Men have been socialized not to show signs of distress, but to conquer it. For females it is much more acceptable to show signs of distress.”
Studies show we can overcome some of our fears by continued exposure to them. By constantly exposing ourselves to our fears, whether it extreme sports, horror movies, or snake and spiders, our tolerance for them will grow, said Sparks.
