Why We Love to Be Scared

Why We Love to Be Scared: Dopamine, Genes and a 2,000 Year Old Horror Story

It’s that time of year again. Halloween. What is it about houses moaning with restless spirits and apparitions rising from graveyard mists that so intrigue us? Today we have movies, TV shows, video games and books regaling us with the most horror-filled scenarios. Dystopias with—name your monster—demons and vampires and zombies threatening to eradicate our species (as if we don’t do a good enough job on our own). There are possessions, evil twins, vivified dolls and deranged clowns. We even have self-proclaimed ghost hunters with their own “reality” shows and the ad revenues, market penetration and viewer numbers demonstrating that scary stuff really can rake in the dough. Why is it we are so enthralled and terrified by the supernatural?

As a matter of fact, fascination with the supernatural is ancient. And some of the best ancient stories can rival today’s plotlines.

But first, let’s raise a basic question. Why do some people seek out terrifying experiences while others recoil at the very thought? This question has sparked the research of David Zald, a professor of psychiatry and psychology at Vanderbilt University, who observes that “Humans have a unique situation where we will seek out things that scare us. We’ve got to ask, what could make this exposure rewarding?”[1]

Chemical structure of dopamine.
Dr. Zald and his colleagues have discovered that dopamine, the chemical in the brain associated with pleasure and reward, seems to be differentiated in thrill–seekers and thrill-avoiders. Those with higher tolerance for risk had less autoreceptors (think of brakes) for dopamine. Thrill-avoiders had more autoreceptors.[2] Evolutionarily speaking, Dr. Zald posits that the ancestors of modern-day thrill-seekers were the most likely to survive because they used their fearlessness to discover ways to combat a harsh and unpredictable environment. These intrepid souls passed on these survival genes to subsequent generations, which likely contributed to the continuation of the species.[3]

Genetics may also play a roll according to researchers at the University of Bonn in Germany. In certain individuals they found that a variant of the gene known as Compt, which affects anxiety, causes more distress in those having the variant than in those who don’t.[4] Thus any stimuli from horror tales meant to send delightful shivers up a viewer’s spine actually can strike numbing terror into those so genetically disposed.

As with so much of modern behavior, our brains and genes and their evolutionary development determine how we respond to the world around us. And it has been that way back to the Roman Empire, where we now proceed in order to hear a 2,000 year old ghost story.

“Como – Dom – Fassade – Plinius der Jüngere” by Wolfgang Sauber – Own work. Wikimedia Commons
Pliny the Younger (61 – c. 113 CE) was a highly respected lawyer, administrator and author in ancient Rome. He is best known for his voluminous trove of letters written during his lifetime that provides a captivating view of Roman culture and times. While his letters run the gamut of topics, it is intriguing to turn to Pliny’s stories of otherworldly occurrences. As we know, the creative arts often arise from personal experiences of the author. We can only speculate that Pliny the Younger’s loss of his uncle in the eruption of Mt. Vesuvius had a profound effect on the 17 year old. His description of the carnage is worthy of any modern disaster movie:

We also saw the sea sucked away and apparently forced back by the earthquake: at any rate it receded from the shore so that quantities of sea creatures were left stranded on dry sand. On the landward side a fearful black cloud was rent by forked and quivering bursts of flame, and parted to reveal great tongues of fire, like flashes of lightning magnified in size.[5]

What is most remarkable about Pliny’s stories is how they transcend time and culture. He is a master storyteller and chronicler able to move an audience nearly 2,000 years later. This imaginative spirit can be seen throughout his writings.

Pliny wrote a number of letters telling of stories he had heard or been told regarding restless spirits and strange incidents for which there could be offered no explanation. Below is a version of Pliny the Younger’s story concerning a restless spirit and a haunted house. You can also listen to an audio version of this story and two other tales of the paranormal from Pliny. As you see, the motifs are quite similar to today’s horror fests of mind-bending, spine-tingling happenings and earth-bound souls. Notice how he builds suspense, using elements that provoke fear and offering vivid descriptions that lend authenticity to the retelling of the tale.

The Library
There was in Athens a house, spacious and open, but with an infamous reputation, as if filled with pestilence. For in the dead of night, a noise like the clashing of iron could be heard. And if one listened carefully, it sounded like the rattling of chains. At first the noise seemed to be at a distance, but then it would approach, nearer, nearer, nearer. Suddenly a phantom would appear, an old man, pale and emaciated, with a long beard, and hair that appeared driven by the wind. The fetters on his feet and hands rattled as he moved them.

Any dwellers in the house passed sleepless nights under the most dismal terrors imaginable. The nights without rest led them to a kind of madness, and as the horrors in their minds increased, onto a path toward death. Even in the daytime–when the phantom did not appear–the memory of the nightmare was so strong that it still passed before their eyes. The terror remained when the cause of it was gone.

Damned as uninhabitable, the house was at last deserted, left to the spectral monster. But in hope that some tenant might be found who was unaware of the malevolence within it, the house was posted for rent or sale.

It happened that a philosopher named Athenodorus came to Athens at that time. Reading the posted bill, he discovered the dwelling’s price. The extraordinary cheapness raised his suspicion, yet when he heard the whole story, he was not in the least put off. Indeed, he was eager to take the place. And did so immediately.

As evening drew near, Athenodorus had a couch prepared for him in the front section of the house. He asked for a light and his writing materials, then dismissed his retainers. To keep his mind from being distracted by vain terrors of imaginary noises and apparitions, he directed all his energy toward his writing.

For a time the night was silent. Then came the rattling of fetters. Athenodorus neither lifted up his eyes, nor laid down his pen. Instead he closed his ears by concentrating on his work. But the noise increased and advanced closer till it seemed to be at the door, and at last in the very chamber. Athenodorus looked round and saw the apparition exactly as it had been described to him. It stood before him, beckoning with one finger.

Athenodorus made a sign with his hand that the visitor should wait a little, and bent over his work. The ghost, however, shook the chains over the philosopher’s head, beckoning as before. Athenodorus now took up his lamp and followed. The ghost moved slowly, as if held back by his chains. Once it reached the courtyard, it suddenly vanished.

Athenodorus, now deserted, carefully marked the spot with a handful of grass and leaves. The next day he asked the magistrate to have the spot dug up. There they found–intertwined with chains–the bones that were all that remained of a body that had long lain in the ground. Carefully, the skeletal relics were collected and given proper burial, at public expense. The tortured ancient was at rest. And the house in Athens was haunted no more.[6]

Don’t miss Thursday’s post, which will feature another haunted house tale, this time told by a modern author who specializes in Gothic twists. More bumps in the night coming your way. Be afraid. Be very afraid.

[1] Ringo, A. (2013, October 31). Why Do Some Brains Enjoy Fear? Retrieved October 21, 2014.

[2] Ibid.

[3] Ibid.

[4] Ibid.

[5] Radice, B. (n.d.). Pliny the Younger, Letters 6.16 and 6.20. Retrieved October 21, 2014, from http://www.u.arizona.edu/~afutrell/404b/web rdgs/pliny on vesuvius.htm

[6] The Library: An Ancient Ghost Story. (n.d.). Retrieved October 21, 2014.

Music and the Mind

Ben Folds featured at ‘Music and Mind’ symposium
by Bill Snyder

“Music and the Mind,” a unique symposium that includes a performance by critically acclaimed singer-songwriter Ben Folds, will be held Thursday, June 12, at 7 p.m. in Ingram Hall of the Vanderbilt Blair School of Music.

Connections between neuroscience, psychology and music will be explored during a panel discussion featuring:

McGill University neuroscientist Daniel Levitin, author of This is Your Brain on Music;

Marianne Ploger, associate professor of music perception and cognition at Vanderbilt; and

David Zald, professor of psychology and psychiatry at Vanderbilt.
Sponsored by the Vanderbilt Brain Institute, the performance and discussion will begin at 7 p.m.

Before the symposium, a research “exposition” will be held in the Ingram Hall lobby beginning at 5 p.m.

The event is free and open to the public, but registration is required.

Science finds a reason some people take risks

Science finds a reason some people take unreasonable risks

Paul Nicklen is accustomed to danger.

His most famous photographs are of animals in the Arctic. He says his goal is to help people realize how important ice is to the survival of the animals. "It just takes one image to get someone's attention," he says.

Paul Nicklen photographs Antarctica Photo courtesy of Paul Nicklen
To get that image, he's willing to take risks. Take his pictures of Atlantic walruses, for example. To get those shots, he had to climb through a hole in the ice and swim up to a 1.5-ton creature with a mouthful of razor-sharp teeth.

Why is he willing to expose himself to dangers like that as a matter of routine?

Psychiatrist and researcher David Zald has a theory. It centers on a chemical called dopamine, the neurotransmitter that stimulates the brain's reward center. You know that feeling of satisfaction you get when, for example, you escape the jaws of an Atlantic walrus and snap the cover photo for a National Geographic? That comes from dopamine.

It's thought that different people produce different amounts of dopamine, and those who are prone to take risks tend to produce more than average. Additionally, through brain scans, Zald has found that people who are more likely to take risks have fewer autoreceptors, which limit the amount of dopamine that can pass through to the brain.

Nicklen and Zald join The Daily Circuit to share their views on risk.


• The Mystery of Risk
Dopamine helps elicit a sense of satisfaction when we accomplish tasks: the riskier the task, the larger the hit of dopamine. Part of the reason we don't all climb mountains or run for office is that we don't all have the same amount of dopamine. Molecules on the surface of nerve cells called autoreceptors control how much dopamine we make and use, essentially controlling our appetite for risk. (National Georgraphic)


The Mystery of Risk

The Mystery of Risk

Why do we do it? What makes an explorer face danger and yet press on when others would turn back?
By Peter Gwin

The man who led a landmark attempt to navigate the entire length of the Grand Canyon did not exactly look the part of a dashing gilded-age adventurer. John Wesley Powell stood only five feet six, had a shock of bristle-brush hair and an unruly tobacco-stained beard that splayed onto his chest. The right sleeve of his jacket hung empty, the result of a minié ball at the Battle of Shiloh. Yet after the war he went on to survey large swaths of the Rocky Mountains, live among hostile bands of Indians, raft the Green and Colorado Rivers, and probe the unmapped labyrinths of one of the world’s largest canyon systems. A stranger might reasonably have wondered what had steered this slight, one-armed university professor to embark on some of the riskiest explorations of his age.

In fact, the same could have been asked of each of the 32 men who joined Powell on January 13, 1888, at Washington, D.C.’s Cosmos Club. Like him, most had pursued their own perilous journeys into unknown wildernesses. Among them were veterans of the Civil War and Indian campaigns, naval officers, mountaineers, meteorologists, engineers, naturalists, cartographers, ethnologists, and a journalist who had crossed Siberia. They were men who had been stranded in the Arctic, survived violent weather at sea, escaped animal attacks and avalanches, endured extreme hunger, and persevered against the soul-crushing loneliness of traveling in remote landscapes.

They had gathered that evening to found the National Geographic Society and had agreed that their new organization’s mission—“the increase and diffusion of geographical knowledge”—would require difficult explorations into unknown territories. Their ethos could be summed up by a passage Powell had written in his journal during his Colorado River expedition almost two decades earlier. After his team, riding in small boats, made several harrowing descents through rapids and over waterfalls, three of the men decided to quit and climb their way out of the canyons, taking their chances crossing the desert. “They entreat us not to go on, and tell us that it is madness to set out in this place,” Powell wrote. And yet “to leave the exploration unfinished, to say that there is a part of the canyon which I cannot explore, having already nearly accomplished it, is more than I am willing to acknowledge, and I determine to go on.”

Exploration of all sorts is rooted in the notion of taking risks. Risk underlies any journey into the unknown, whether it is a ship captain’s voyage into uncharted seas, a scientist’s research on dangerous diseases, or an entrepreneur’s investment in a new venture. But what exactly pushed Christopher Columbus to embark on a voyage across the Atlantic, or Edward Jenner to test his theory for an early smallpox vaccine on a child, or Henry Ford to bet that automobiles could replace horses? For that matter, why did Powell ignore the cautions of his men and the obvious dangers in front of him to venture deeper into the wilds of the Grand Canyon?

Some of the motivations for taking risks are obvious—financial reward, fame, political gain, saving lives. Many people willingly expose themselves to varying degrees of risk in their pursuit of such goals. But as the danger increases, the number of people willing to go forward shrinks, until the only ones who remain are the extreme risk takers, those willing to endanger their reputation, fortune, and life. This is the mystery of risk: What makes some humans willing to jeopardize so much and continue to do so even in the face of dire consequences?

One hundred and twenty-five years after that night at the Cosmos Club, scientists have begun to open up the neurological black box containing the mechanisms for risk taking and tease out the biological factors that may prompt someone to become an explorer. Their research has centered on neurotransmitters, the chemicals that control communication in the brain. One neurotransmitter that is crucial to the risk-taking equation is dopamine, which helps control motor skills but also helps drive us to seek out and learn new things as well as process emotions such as anxiety and fear. People whose brains don’t produce enough dopamine, such as those who are afflicted with Parkinson’s disease, often struggle with apathy and a lack of motivation.

On the opposite end of the spectrum, robust dopamine production holds one of the keys to understanding risk taking, says Larry Zweifel, a neurobiologist at the University of Washington. “When you’re talking about someone who takes risks to accomplish something—climb a mountain, start a company, run for office, become a Navy SEAL—that’s driven by motivation, and motivation is driven by the dopamine system. This is what compels humans to move forward.”

Dopamine helps elicit a sense of satisfaction when we accomplish tasks: the riskier the task, the larger the hit of dopamine. Part of the reason we don’t all climb mountains or run for office is that we don’t all have the same amount of dopamine. Molecules on the surface of nerve cells called autoreceptors control how much dopamine we make and use, essentially controlling our appetite for risk.

In a study conducted at Vanderbilt University, participants underwent scans allowing scientists to observe the autoreceptors in the part of the brain circuitry associated with reward, addiction, and movement. People who had fewer autoreceptors—that is, freer flowing dopamine—were more likely to engage in novelty-seeking behavior, such as exploration. “Think of dopamine like gasoline,” says neuropsychologist David Zald, the study’s lead author. “You combine that with a brain equipped with a lesser ability to put on the brakes than normal, and you get people who push limits.”

This is where the discussion often confuses risk takers with thrill seekers or adrenaline junkies. The hormone adrenaline is also a neurotransmitter, but unlike dopamine, which can push us toward danger in the course of achieving certain goals, adrenaline is designed to help us escape from danger. It works like this: When the brain perceives a threat, it triggers the release of adrenaline into the bloodstream, which in turn stimulates the heart, lungs, muscles, and other parts of the body to help flee or fight in a life-threatening situation. This chemical release generates a feeling of exhilaration that continues after the threat has passed, as the adrenaline clears the system. For some people that adrenaline rush can become a reward the brain seeks. They are prompted to induce it by going to scary movies or engaging in extreme sports or by artificial means such as taking narcotics.

But adrenaline isn’t what motivates explorers to take risks. “An Arctic explorer who’s slogging through ice for a month isn’t motivated by adrenaline coursing through his veins,” says Zald. “It’s the dopamine firing in his brain.”

Critical to this process is how the brain measures risk. Photographer Paul Nicklen describes how his definition of acceptable risks has evolved over time. “When I was a kid living in the Arctic, I would paddle ice floes like rafts, which was probably risky. Then I learned to dive, and I just kept wanting to go deeper, stay in the water longer, get closer to the animals.

“For a long time I told myself I wouldn’t dive with Atlantic walruses,” he says. “The reason there aren’t many photos of Atlantic walruses swimming under polar ice is because it’s incredibly difficult and dangerous to cut a hole in ice that’s several feet thick and dive into water barely above freezing and try to get close to 3,000-pound animals that can be highly aggressive when disturbed. There are a lot of ways to die doing that.”

Nicklen’s reward for taking those risks is capturing walrus images that are so close, so three-dimensional, that they cast a spell over a reader. “I want readers to feel like they are a walrus, swimming with other walruses. For fleeting moments, that’s what I feel like at times. The only way I can describe how powerful a feeling that is is through these pictures. I guess I am sort of addicted to it.”

The movement of Nicklen’s personal “risk line” is his brain’s way of recalibrating risks based on past experience, says Larry Zweifel. “He is very comfortable recognizing what potential threatening situations look like and how to successfully avoid those situations. His brain calculates the risks and the potential reward, facilitated by his dopamine system, which then motivates him to do the dive.”

And yet, says Zweifel, “if he were to repeatedly dive with animals that threaten his life and encounter many near-death experiences but continue to make such dives regardless of the negative outcomes, then that would be compulsive behavior, which can become pathological, like losing everything because of a gambling problem.”

Acclimating to risk is something we all do in our daily lives. A good example of this occurs when learning to drive a car. At first a new driver may fear traveling on freeways, but over time that same driver with more experience will merge casually into speeding traffic with little consideration for the significant potential dangers.

“When activities become routine and familiar, we let our guard down, especially when nothing bad happens for quite some time,” says Daniel Kruger, an evolutionary psychologist at the University of Michigan. “We have a system designed to react to short-term threats, but when it is on all the time, it can have a detrimental impact on the body,” such as elevating blood sugar and suppressing the immune system.

This familiarity principle can also be applied to help deal with the fear associated with high-risk situations. By practicing an activity, humans can become used to the risk and manage the fear that arises in those situations, says Kruger. “Tightrope walkers start by learning to walk on a beam on the ground and then move to a rope just off the ground, until finally they graduate to the high wire. It appears more dangerous to an audience that has never walked a tightrope than it does to the tightrope walker.”

Last October former Austrian paratrooper Felix Baumgartner took this principle to the extreme when he rode a helium balloon into the stratosphere and leaped out, descending 22.6 miles to the Earth. His record-setting parachute jump included a four-and-a-half-minute free fall that exceeded 843 miles per hour.

In preparation for such an epic feat, he and his team had spent five years refining his equipment, using an altitude chamber to simulate the temperatures and pressures he would encounter, and practicing jumps from various altitudes.

“To people on the outside, the jump looks like an extraordinary risk,” Baumgartner says. “But if you look carefully at the details, you find out the risk is minimized as much as possible.”

It is, however, important to remember that a person doesn’t have to jump from space to be a risk taker, says Kruger. “Taking risks is part of our human legacy. We are all motivated to survive and reproduce. To accomplish both involves choices that might lead to negative outcomes. Essentially, that is risk taking.”

The notion that we are all descended from risk takers fascinates writer Paul Salopek. “Humans leaving the Great Rift Valley were the first great explorers,” he reasons. With this in mind, he has embarked on a seven-year, 22,000-mile journey to follow in their footsteps as they radiated out of Africa and across the planet. It is the trail of some of the first risk takers, who along the way took bites of unknown plants and animal flesh, learned to traverse deep water, and discovered ways to sustain their body temperature in cold.

In making this journey Salopek is taking his own set of extraordinary risks. “The idea is to walk the daily length that nomads did when they left Africa 50,000 to 70,000 years ago. Scientists have found that to be about ten miles a day,” he said in January, shortly before he began the trek from the site in northeastern Ethiopia’s Afar region where some of the first anatomically modern human fossils were found. At this pace he plans to pass through three continents and 30-odd international borders, as well as scores of languages and ethnic groups, mountain ranges and rivers, deserts and high plains, dying cities and bustling new metropolises.

Salopek is no novice when it comes to challenging travel. In August 2006 he was covering the conflict in Darfur, Sudan, as part of an assignment for National Geographic when he was kidnapped by militiamen, who beat and threatened to kill him. He was eventually released.

“The philosophy behind this walk is to get readers to focus less on the notion that the world is a dangerous place,” he says. “The world can kill you in a heartbeat, whether you stay at home or leave home.” Instead, he hopes “to get readers to think about the wider horizons, the wider possibilities in life, the trails taken and not taken, and be comfortable with uncertainty.”

Basically Salopek wants to remind people that at our innermost core we are all risk takers, if some more than others. And this shared willingness to explore our planet has bound our species from the very beginning.

It’s a noble idea, albeit one that is fueled by dopamine.

Brain Chemistry and Work Ethic

Dr. David Zald, Vanderbilt University – Brain Chemistry and Work Ethic
By Bradley Cornelius

In today’s Academic Minute, Dr. David Zald of Vanderbilt University reveals why some people are more willing to go the extra mile for a potential reward.

David Zald is an associate professor of psychology and psychiatry at Vanderbilt University and a fellow of the Vanderbilt Brain Institute. He is also director of the Affective Neuroscience Lab, a facility working to understand the neural and neuropharmacological systems involved in emotion and motivation, and the relationship of individual differences in these circuits to personality and psychopathology. He holds a Ph.D. from the University of Minnesota.

About Dr. Zald

Some people work harder than others. Some individuals are so motivated by potential rewards that they will expend effort even if the odds of success are low, while others take a more economical attitude towards expending energy. My lab became interested in the decision processes involved in expending energy in the context of depression, during which people are often unmotivated to work.

We created a task called the Effort Expenditure for Rewards Task, or Effort for short, which measures how much individuals are willing to work for rewards. During each trial, participants must choose whether to do an easy task for a dollar or a hard task to get a larger amount of money. The amount of money for the high reward and the probability of receiving the reward changes on each trial. People naturally choose the hard task more frequently when it has substantially higher rewards than the easy task. Similarly people are more like to do the hard task when the probability of getting the reward increases.

We have been particularly interested in the impact of the neurotransmitter dopamine on decisions about effort. Studies in rats indicate that if you deplete dopamine, the rats decrease their willingness to work for food. In humans, we have found that if you cause someone to increase dopamine release, for instance by giving them amphetamine, they will select the harder task more often than if they are given a placebo, especially on trials in which the probability of getting rewarded is low.

Using positron emission tomography, which lets us safely measure levels of dopamine receptors and dopamine release in humans, we have recently found that individual differences in dopamine release in specific areas of the brain are predictive of people’s willingness to work for rewards on the Effort. Although we often think of the willingness to work as a moral virtue, these findings suggest that some of our differences in work ethic relate to basic features of neurochemistry.