The amygdala is a section of the brain that is responsible for detecting fear and preparing for emergency events. This lesson discusses the amygdala, its functions, and its role in our perception of fear and other emotions.

The Role of Fear

Do you have any fears? For some people, their biggest fear may be death. For others, it may be public speaking. In fact, most humans will have at least one or more things that they fear in life, no matter how dangerous or innocent the object of that fear may be.
But there is a reason for that. Fear often helps us with self-preservation. We feel fear, as well as related emotions, in order to protect ourselves from danger and to heighten our awareness. This awareness is thought to be controlled by a section of the brain known as the amygdala. Let's discuss the amygdala and how it functions in the well-being of the human body.

Definition and Function of the Amygdala

The amygdala is an almond-shaped section of nervous tissue located in the temporal (side) lobe of the brain. There are two amygdalae per person normally, with one amygdala on each side of the brain. They are thought to be a part of the limbic system within the brain, which is responsible for emotions, survival instincts, and memory. However, this inclusion has been debated heavily, with evidence that the amygdalae function independently of the limbic system.
The amygdala is responsible for the perception of emotions such as anger, fear, and sadness, as well as the controlling of aggression. The amygdala helps to store memories of events and emotions so that an individual may be able to recognize similar events in the future. For example, if you have ever suffered a dog bite, then the amygdalae may help in processing that event and, therefore, increase your fear or alertness around dogs. The size of the amygdala is positively correlated with increased aggression and physical behavior.
The amygdala in humans also plays a role in sexual activity and libido, or sex drive. It can change in size and shape based on the age, hormonal activity, and gender of the individual. For example, males who have low testosterone, or who may have been castrated, (had their testicles removed), tend to have smaller amygdalae, and, in turn, may also have a lower sex drive.

Fear and the Amygdala

It is important to state that the amygdalae are most functional in immediate fear situations. Whenever our senses detect a change in our surroundings that could be dangerous, the amygdalae are responsible for preparing the body for escape or defense. This is part of what is known as the startle circuit of the brain, which controls our response to being startled.