Fear can be as old as life on Earth.It is a fundamental reaction, deeply connected to us, developed throughout the history of biology, to protect organisms against the perceived threat to their integrity or existence. Fear can be as simple as the shudder when touching a snail’s antenna or as complex as existential anxiety in a human.
Whether we love or hate experiencing fear, it’s hard to deny that we certainly revere it, dedicating an entire holiday to celebrating fear: Halloween.
When thinking about brain circuits and human psychology, some of the major chemicals that contribute to the “fight or flight” response are also involved in other positive emotional states, such as happiness and excitement. So it makes sense that the high arousal we experience during a scare can also be experienced in a more positive way. But,What makes the difference between being in a “rush” and feeling completely terrified?
Psychiatrists treat fear and study its neurobiology. Studies and clinical interactions suggest that an important factor in how we experience fear has to do with context. When our “thinking” brain gives feedback to our “emotional” brain and we perceive ourselves as if we are in a safe space,we can quickly change the way we experience that high arousal, going from one of fear to one of pleasure or emotion.
For example, when we walk into a haunted house during Halloween time, you anticipate that if a zombie jumps at you, you know it’s not really a threat, so you can quickly relabel the experience in your brain. In contrast, if you were walking down a dark alley at night and a stranger started chasing you, your thinking and emotional areas of the brain would agree that the situation is dangerous.
The fear reaction begins in the brainand spreads through the body to make adjustments for the best defense or flight reaction. The fear response begins in a region of the brain called the amygdala. This set of almond-shaped nuclei in the temporal lobe of the brain is dedicated to detecting the emotional prominence of stimuli: how much something draws our attention.
For example, the amygdala is activated every time we see a human face with an emotion. This reaction is most pronounced with anger and fear. A threatening stimulus, such as the sight of a predator, elicits a fear response in the amygdala, which activates the areas involved in preparing the motor functions involved in fight or flight. It also triggers the release of stress hormones and the sympathetic nervous system.
This leads to changes in the body that prepare us to be more efficient in danger: the brain goes into hyperalert mode, the pupils dilate, the bronchial tubes dilate, and breathing speeds up. Heart rate and blood pressure rise. Blood flow and glucose flow to skeletal muscles increase. Organs not vital to survival, such as the gastrointestinal system, slow down.
Similar to other animals, we often learn fear through personal experiences, such as being attacked by an aggressive dog or watching other humans being attacked by an aggressive dog.
However, a unique and fascinating evolutionary way to learn in humans is through instruction: we learn from spoken words or written notes. Thus, if a sign says that there is a dangerous dog, the proximity to the dog will provoke a fear response.
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