The Amygdala: Exploring The Function And Psychology Of Fight Or Flight

Ongoing research has allowed researchers to label various parts of the brain and understand how they function alone and in connection with one another. Per this research, many experts believe that the amygdala is the part of the brain that can most closely be associated with the fear response, or “fight or flight”.

Based on their understanding of brain function, clinicians have been able to develop therapeutic interventions to help clients cope more effectively with fear, stress and anxiety disorders in many different contexts. 

While many believe that we've learned much about the role of the amygdala and the fight or flight response, researchers generally acknowledge that the amygdala has other functions that we don't yet fully understand. However, the information that we do have available can provide insight into why we respond and behave in certain ways, and what we can do to make our responses healthier.

Amygdala function: Psychology of the brain

The amygdala is a part of the limbic system.

In a general sense, the amygdala can play a strong role in why we display emotions. The amygdala can have several functions in a neurotypical brain, but it may be most known for its role in helping our bodies process fear by initiating a fight or flight response to dangerous or threatening situations or stimuli.

Scientists have recently learned that the amygdala can also activate in response to positive stimuli, and can be associated with memories that have either a strong positive or negative component. Current studies are exploring how the amygdala might affect other realms, such as addiction and social interaction.

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Amygdala function: The psychology of fight or flight

To understand how the amygdala functions, you may consider how many people react when faced with a common fear: public speaking. At some point in our lives, nearly all of us might have been faced with the prospect of public speaking, or glossophobia. Estimates suggest that about 73% of people have some degree of glossophobia.

With this in mind, the fear of public speaking can create physiological symptoms such as an increased heart rate, increased respiration, butterflies in the stomach, and brain fog prior to a presentation due to the perception of stressful or “threatening” stimuli that can be associated with the action of public speaking.

When we feel threatened, the hypothalamus can trigger a fight-or-flight response. This can start by the thalamus sending a signal directly to the amygdala before it gets processed in the cortex—which is generally where higher-level thinking occurs in most. This is why we can experience a sense of fear before we even have time to think about it. 

As the time nears to begin speaking, the amygdala can tell the hypothalamus to signal the body to prepare an extra dose of energy to flee the perceived threat. The body's response to this might be to increase one’s heart rate and respiration rate, as well as activate the sweat glands for cooling and a fast getaway.

When we think about a potential threat, our body can respond by becoming nervous, even if the threat never materializes.

What has research shown us about the function of the amygdala?

Heinrich Kluver and Paul Bucy conducted some of the first experiments involving the amygdala. For example: they removed the amygdala of rhesus monkeys and recorded drastic changes in their behavior. 

The monkeys in this experiment generally became docile and seemed to display little to no fear. This phenomenon can be defined as Kluver-Bucy Syndrome, and it has led to similar studies that explored the role of the amygdala in fear and anxiety disorder formation.

In other studies, researchers used mice to study the role of the amygdala in fear. According to related research documentation, they worked with mice that had intact amygdalae. The experiment generally consisted of a researcher playing a tone and then giving the mouse an uncomfortable shock on their feet. Thus, they conditioned the mice to associate the tone with the shock. After repeated incidences of playing the tone and delivering the shock, the mice began to display fear as soon as the tone was played.

As a follow-up experiment, researchers used mice that had lesions on their amygdalae and repeated the steps of playing the tone and delivering the foot shock. The mice in this test group reportedly weren't able to remember that the tone came before the shock, and didn't display fear at the sound of the tone.

A “handy” model of the brain that demonstrates the fight or flight response

Dr. Daniel Siegel is a notable psychiatrist and clinical professor at UCLA, who has done extensive work in neuropsychiatry, trauma, and attachment-related areas of study. In an attempt to develop a simple model to explain the complex inner workings of the brain, Dr. Siegel developed a “hand model” that can demonstrate the functions of various parts of the brain in connection with the fight or flight response.

The hand model can be shown as follows: Place one of your hands up and put your thumb in the middle of your palm. Then curl your fingers over the top of your thumb. Your knuckles should for this experiment, be facing forward. Your palm and fingers can represent your brain, and your wrist can represent your spinal cord.

Now, if you lift your fingers and raise your thumb, you can see the “inner brainstem” that can be represented by the palm of your hand. You can then put your thumb back down, and you can now see the approximate location of the limbic area of the brain. This is considered by many to be the area that can contain the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus in a traditional anatomical form.

The brainstem, the limbic area, and the cortex can commonly be referred to as the "triune brain." We can consider this triune structure in the context of the brain’s two hemispheres, located on the left and right side of the structure. To have neural integration and functionality, the signals generally must be sent through both halves of the brain and link the functions in both hemispheres. 

Let's take a closer look at what this can look like by region.

Brainstem

The brainstem is thought to control the body's energy levels through heart rate and respiration. It also can control our states of arousal. The activity within the brainstem can shape the areas of the brain above it, which are the limbic and cortical regions. During times of danger, clusters of neurons in the brainstem can put us in survival mode as they move the body into a state of fight, flight or freeze.

Limbic area

The limbic area is hidden deeply in the brain. The limbic area is also thought to be a critical region that can aid us in forming bonds and developing relationships. The hypothalamus, located in this area, can be considered the master endocrine “control center.” It can deliver and retrieve hormones via the pituitary gland.

When we feel stress, this can start a chain reaction in which the pituitary gland might stimulate the adrenal glands. These can, in turn, release cortisol and mobilize our energy. The process might work well in the short term, but it can create problems when cortisol levels remain elevated for long periods.

Cortex

The outer layer of the brain is known as the cortex. The prefrontal cortex lies just behind the forehead and is considered to be the spot that can connect the triune brain. The cortex is generally thought to control the subcortical, limbic, and brainstem areas, which can help us stay tuned in, connected, balanced and flexible. This control can be important because we can face many challenges on a daily basis that can require the triune brain to function well. When the limbic system becomes uncontrolled, we can lose our sense of connectedness and balance.

PTSD and fight or flight

Post-traumatic stress disorder (PTSD) is a mental health disorder that can occur after experiencing a deeply frightening, threatening event. Many experts believe that to recover from PTSD, we must risk exposing ourselves to feared memories, situations and places—in effect, retraining our brains at a structure level. 

Two types of therapy that can be effective for PTSD in most can include cognitive behavioral therapy and EMDR. Others may find relief through supportive strategies and lifestyle changes offered by a skilled in-person or online therapist. 

Other mental health disorders can develop because of issues with the limbic system or an overactive stress response. These can often be combatted and managed through professional intervention. 

How can online therapy help those “stuck” in fight-or-flight?

When you feel stuck in fight or flight mode, controlling the amygdala can help your body return to a normal state. If you need help learning how to do this, working with a therapist could be beneficial. However, when you’re experiencing PTSD, it may be difficult to attend in-person therapy. 

This is where online therapy can be helpful, as it can allow you to receive mental health care from your home. BetterHelp is an online counseling platform that can connect you with a therapist who has experience with stress and conditions like PTSD. You can talk with your BetterHelp therapist through phone calls, video chats or in-app messaging, according to your comfort level.

Online counseling can be an effective treatment for a variety of stress-related disorders, including PTSD. One study found details that suggest that an internet-based therapeutic intervention reduced PTSD severity as well as symptoms of co-morbid depression and anxiety disorder formation. Researchers also noted that “a positive and stable therapeutic relationship could be established online”.

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