The Role of the Amygdala in Human Behavior and Emotion

The amygdala is a region of the brain that is involved in processing emotions, particularly fear. While emotions are not facts, they are one way that our brain keeps us safe and aware of our surroundings. For example, fear and anxiety exist to alert us of potential threats.

Since our emotions inform us about our environment, they impact behavior. When emotions serve as a warning of potential danger, we can act to protect ourselves. At the same time, our emotions do not always give us accurate information about threats and can cause anxiety and stress when we are not actually unsafe.

Learn more about the role of the amygdala in how we feel and behave.

What Is the Main Function of the Amygdala?

According to Shaheen E. Lakhan, MD, PhD, FAAN, a neurologist and chief medical officer of Click Therapeutics in New York, the amygdala is a “tiny little almond-shaped structure [that] is responsible for all that is emotion—largely fear, anger, pleasure, and anxiety.”

While amygdala responses can alert us when we are unsafe or need to take steps to manage stress, the amygdala can also become overactive in trauma survivors, contributing to symptoms of post-traumatic stress disorder. Additionally, research shows that the amygdala plays a role in mood disorders, including major depressive disorder.

What Feelings Does the Amygdala Control?

The amygdala is involved in the regulation of anxiety, aggression, stress responses, memories tied to emotions, and social cognition. It is involved in activating the fight or flight response, impacting how we react to potentially dangerous situations.

While this is adaptive and helps us stay safe, it can become dysregulated and lead to an overactive response. Those with an overactive amygdala may feel these responses acting up even when they are not in danger. This can be stressful and exhausting.

Since the amygdala is connected to emotional memories as well as current emotions, it is involved in flashbulb memories, or vivid, detailed memories of surprising and emotionally significant events or historical moments.

What Can Damage the Amygdala?

While our skull protects our brain from damage, the amygdala is not immune from both internal and external damage. Dr. Lakhan shares, “The amygdala can be damaged by stroke, infections like the Herpes Simplex Virus, neurodegenerative diseases like Alzheimer’s, and brain tumors.” You can also sustain a concussion or traumatic brain injury that damages the amygdala.

It is possible to sustain irreversible brain damage. However, even if your amygdala is damaged, you may be able to recover, especially with support and treatment. According to Dr. Lakhan, “The brain has a remarkable capacity for compensating and reorganizing called neuroplasticity.” Neuroplasticity is our nervous system’s ability to adjust and change based on damage or need.

What Happens When the Amygdala Is Activated?

The amygdala becomes triggered (or activated) in response to perceived threats in order to keep you safe by activating fear responses. As Dr. Lakhan puts it, “When we perceive a threat, the amygdala kicks in to activate our body’s stress response—our fight or flight response." This works through the autonomic nervous system, increasing your heart rate, blood pressure, breathing, and alertness.

By engaging the autonomic nervous system, the amygdala prepares you to protect yourself and stay safe. It allows you to react quickly to a perceived threat. For example, if an animal attacks you, and you need to escape, this response can ensure that you have the energy and muscle power to run away. If you are unable to get away, this response routes your resources into being able to fight off the threat.

After the threat is gone, or after you realize that there was no threat to begin with, the amygdala is meant to power back down with the help of your frontal lobe. Dr. Lakhan says, “There are mechanisms to dampen this response so that you are not in a constant state of anxiety. The frontal part of your brain actually puts the brakes on the amygdala and says basically, there are no more pressing things.”

However, for some, the frontal lobe does not effectively shut down the amygdala’s triggered state. As noted previously, this can occur following trauma. If you live in a chronically stressful or traumatic state, the amygdala may remain activated long-term out of necessity. When you must always be on alert for danger, the amygdala can switch on and not switch off in an effort to ensure your survival. While this can keep you safe in the moment, it wears you down over time.

How Can I Calm My Amygdala?

The good news is, even if the amygdala becomes overactive in response to trauma or damage, it is possible to reverse these effects. “The amygdala can be trained," Dr. Lakhan says. "Because the brain interacts with a couple key other brain regions and forms what are known as brain circuits, the best exercise actually strengthens these circuits.”

Therapy by a qualified mental health professional can treat the symptoms that come from an overactivated amygdala. If a traumatic event or events caused this response, trauma-informed therapy can help. Your therapist can also help you develop skills and techniques to reduce your amygdala’s activation, such as relaxation exercises that can bring down activation in the autonomic nervous system.

Dr. Lakhan shares the following tips for deactivating your amygdala and re-engaging your frontal lobe:

• Deep breathing: “Taking slow, deep breaths down the diaphragm and focusing on exhaling is a great technique.”
• Exercise: “Physical activity like walking, dancing, or yoga, can help to regulate the amygdala.”
• Cognitive behavioral therapy: “Cognitive restructuring can replace negative or catastrophic thinking patterns with more positive and realistic ones.”