It is reported The Conversation.
In many cultures, cowardice and bravery have more to do with the heart or gut than with the brain. But science traditionally views the brain as the place where fear and anxiety are born and processed.
American psychiatrist and neurobiologist Arash Javanbakht explained how fear works in the brain and body, and what excessive anxiety does to the body. Research shows that while emotions originate in the brain, the body carries out their commands.
It is assumed that there are several key areas of the brain that are actively involved in the processing of fear. When you perceive something as dangerous, these sensory signals are first sent to the amygdala. This small amygdala-shaped area of the brain, located near the ears, determines the salience or emotional significance of a situation and how to respond to it.
Threat detection is a vital part of this process, and it must be fast. Primitive people did not have much time to think when a lion rushed at them. Because of this, the amygdala evolved to bypass the areas of the brain involved in logical thinking.
“For example, seeing an angry face on a computer screen, the amygdala can immediately cause a noticeable reaction of the amygdala, and the viewer is not even aware of this reaction,” said the psychiatrist.
The hippocampus is located nearby and is closely related to the amygdala. He participates in remembering what is safe and what is dangerous. For example, after seeing an angry lion in the zoo, the amygdala causes a fear reaction. But the hippocampus intervenes and blocks this reaction, because when a person is in a zoo, he is not in danger.
The prefrontal cortex, located above the eyes, is largely responsible for the cognitive and social aspects of fear processing. For example, a person may be afraid of a snake until he reads a sign that it is non-venomous.
But if the brain decides that a fear response is warranted, it activates a cascade of neural and hormonal pathways to prepare the body for immediate action. Part of the fight-or-flight response, such as heightened attention and threat detection, occurs in the brain. But most of the action takes place in the body.
The motor cortex of the brain sends fast signals to the muscles to prepare them for fast and powerful movements. These include the muscles of the chest and abdomen, which help protect the vital organs in these areas. This can contribute to a feeling of tightness in the chest and stomach in stressful situations.
The autonomic nervous system accelerates the systems involved in fight or flight. Its neurons are distributed throughout the body and are especially densely located in places such as the heart, lungs, and intestines. These neurons trigger the adrenal glands, which release hormones such as adrenaline, which travel through the bloodstream to these organs and increase the speed with which they respond to fear.
To ensure adequate blood supply to the muscles when there is a great demand on them, signals from the autonomic nervous system increase the heart rate. A person begins to feel an increase in heart rate and strength of contractions in the chest, which is why he can associate the feeling of strong emotions with the heart.
In the lungs, signals from the autonomic nervous system expand the airways and increase the frequency and depth of breathing. Sometimes this leads to a feeling of shortness of breath.
As a result, all bodily sensations are transmitted back to the brain, which is already in a state of anxiety and high alert.
Although feelings of fear and anxiety originate in your brain, you can also feel them in your body. Emotions occur both in the body and in the brain, but the very awareness of their existence occurs with the help of the brain.
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