Fear of predators
Fear of predators, we all have it. Some have it more than others. Some deal with it better than others. Is this fear of predators an instinct, or is it a learned response?
In the early 1900s, American psychologist John Watson wanted to see if he could teach an 11-month-old baby named Albert to become scared of arbitrary things. He presented Albert with a rat, and every time the baby reached out to touch it, Watson hit a steel bar with a hammer, producing a horrendous clang. After several rounds with the rat and the bar, Watson then brought out the rat on its own. “The instant the rat was shown, the baby began to cry. The “little Albert” study, besides being cruel, was badly designed. Watson did not control it carefully to rule out a wide range of possible interpretations.
Later experiments used rats rather than people as their test subjects. In one such experiment, a rat was placed in a cage with a light. The light came on a few times so the animal could get accustomed to it, then the scientists would turn on the light and then give the rats a little electric shock. After a few rounds, the rats would respond fearfully to the light, even if no shock came.
Further research revealed that the amygdala—an almond-shaped cluster of neurons deep within the brain—plays a pivotal role in the fear-association response in rats and humans. The sight of a loaded gun, for example, triggers activity in this part of the brain. People with an injured amygdala have dampened emotional responses and so do not learn to fear new things through association.
Research into fear response in humans
In the 1980s, Caroline and Robert Blanchard, working together at the University of Hawaii, carried out a pioneering study on the natural history of fear. They put wild rats in cages and then brought cats gradually closer to them. At each stage, they carefully observed how the rats reacted. They found that the rats responded to each kind of threat with three distinct sets of behaviors:
- One. The first kind of behavior is a reaction to a potential threat, in which a predator, such as a cat, is not visible but there is good reason to worry that it might be nearby, such as the scent of fresh cat urine. In such a case, a rat will proceed cautiously, assessing the risk.
- Two. The second behavior occurs when the rat sees the cat. The rat will freeze and then choose what to do next, either remain immobile or run away.
- Three. In the third behavior, the cat notices something and walks toward the rat to investigate. At this point, the rat will flee if it has an escape route. If the cat gets close, the rat will choose either to fight or to run for its life.
Dean Mobbs, a neuroscientist at the Medical Research Council in Cambridge, England, wondered if humans have similarly layered fear responses. They programmed a survival-themed video game that subjects could play while lying in an MRI scanner. The game is like Pac-Man, a video game popular at the time. In the researcher’s game, you see yourself as a triangle in a maze and press keys to maneuver through it. At some point, a circle appears. This is a virtual predator being guided by an artificial intelligence program to seek you out. If the predator captures you, you receive a small electric shock on the back of your hand. Although a simple game, it triggered some remarkably intense feelings.
Mobbs measured the skin conductance of the players with a device like a lie detector. He found that when the predator was bearing down on players, they often experienced the same changes to their skin as those seen in people having panic attacks. There were two kinds of predators, a less adept one from which it was easy to escape, and a smarter one that was more likely to capture its victim. When people were chased by the better predator, they showed a stronger panic response in their skin, and they also crashed into the walls of the maze more often.
Changes in the brain
Big changes were also happening inside the brains of the players. The predators would first appear on the far side of the maze, and, while they remained at a distance, the same brain regions tended to become active in the players, a network of areas that included parts of the amygdala as well as some other structures in the front of the brain. However, when the predator was closing in, those brain regions shut down and a network of previously quiet regions farther back in the midbrain became active.
One of the midbrain regions that Mobbs observed becoming active in humans when a “predator” was close is an area called the periaqueductal gray region. This area showed higher activity in the people who crashed into the walls more often, providing further evidence that it plays an important role in panic.
Researchers have studied the anatomy of fear more directly in rats. By manipulating different areas of the rat brain, they have been able to alter parts of the standard fear-driven sequence of behavior. When neuroscientists put electrodes into the periaqueductal gray region of rat brains and stimulated the neurons there, the creatures immediately started to run and jump uncontrollably.
The new research suggests that fear is not a single thing; rather, it is a complex, ever-changing strategy that mammal brains deploy to cope with danger. When a prey sees a predator at the distance, the prey powers up a forebrain network that primes its body, raising the heartbeat and preparing it for fast action, and it sharpens the brain’s attention to the outside world by evaluating threats, monitoring subtle changes, and running through possible responses. The forebrain network also keeps the midbrain network shut down so that, instead of fleeing at top speed, the prey keeps very still at first. As the predator gets closer, the forebrain’s grip on the midbrain loosens and the midbrain initiates a fight or flight response. At the same time, it shuts down the slower, more deliberative forebrain since this is not a time for thinking.
The predator-defense response has helped mammals, including humans, survive for millions of years. However, humans may also imagine threats that do not exist that may lead to crippling chronic anxiety. Some people are not able to keep their periaqueductal gray and other midbrain regions under control. As we perceive predators getting closer, our brains normally make the switch from the forebrain to the midbrain regions; however, people who suffer panic disorders may misjudge threats, seeing them far more imminent than they are.
In modern-day society, we as humans are still faced with predators; and, as has been for eons, our biggest predators are other humans. As martial artists, we must learn how to control our predator-defense response so we can use it to outsmart human predators and defeat them, or, if necessary, eliminate them.
- Zimmer, Carl. (2010). Are you a man or a mouse? No matter how you answer, you experience fear the same way in your brain. Discover magazine. January-February issue.