The amygdala is a part of the brain that gets its strange-sounding name from the Greek word for almond – amygdale. The amygdala received its name because of its almond-like shape. It is actually a paired structure, with one located on each side of the brain. So, where exactly is this “brain-almond,” and what does it do?
The amygdala resides in the medial temporal lobe, in front of the hippocampus, with one in each hemisphere. It forms part of a neural network system called the limbic system, which is responsible for many aspects of memory and emotion. The amygdala also activates the fight-or-flight response.
Previously scientists believed that the amygdala was primarily involved in fear and negative emotions evoked by unpleasant stimuli. But today, they recognize that these almond-shaped structures are also involved in positive emotions elicited by pleasant or rewarding stimuli. The amygdala also plays a part in memory. There is much more to it than fight-or-flight reactions.
All About The Amygdala
The amygdala plays an elemental role in the way animals and humans judge and responds to challenges and threats in their environment. It does this by assessing the emotional significance of sensory information and triggering an appropriate reaction. The amygdala ties emotional meaning to our memories, decision-making, and reward-processings. (1)
The Anatomy Of The Amygdala
The amygdala makes up only about 0.3% of the human brain, with a volume of 2.25 cm³. (3)
The amygdala is made up of clusters of neurons. The largest group, the basolateral complex, sits more or less in the lateral and middle sections of the amygdala. It includes the basal, lateral, and accessory-basal nuclei. (2)
The lateral nucleus receives most of the input from the sensory cortices of all the senses. Sensory cortices are those regions of the brain that represent data about sensory stimuli.
The cortical and medial nuclei form the amygdala’s cortico-medial group. The olfactory bulb and pyriform complex send information about smells directly to the cortico-medial amygdala.
The amygdala also receives information from various cortical and subcortical systems. It receives significant input from the prefrontal cortex, especially the orbitofrontal and anterior cingulate cortices. The amygdala also gets a lot of information from the hippocampus, rhinal, and insula cortices.
The amygdala sends out information to cortical and subcortical brain areas. It directs the central nucleus towards structures that deal with different physiological, autonomic, and behavioral expressions of emotion.
The accessory-basal and basal nuclei project significant output to the cerebral cortex. These projections may be the basis for the amygdala’s role in cognitive processes such as attention, memory, and decision-making.
The Hemispheric Specializations Of The Amygdala
One study noted that the right amygdala induced negative emotions when stimulated with electrical impulses, especially sadness and fear. Research also suggests that the left amygdala is involved in the brain’s interpretation of the reward system. (9)
The amygdala in each hemisphere has a particular function in how we perceive and modulate emotion. Both sides have separate memory systems but cooperate to encode, store, and interpret emotions.
The Functions Of The Amygdala
The amygdala is a crucial structure involved in processing emotions and encoding memories, especially in the case of emotional remembrances. It connects to several other parts of the brain that control different behavioral functions. The amygdala is best known for its role in the fight-or-flight response, but it serves several other purposes. (4)
Amygdala Function: Fight Or Flight Response
One of the amygdala’s principal functions is to sense danger in our environments and prepare our bodies to fight or get away. When the eyes or ears, or sometimes both senses, pick up any form of perceived danger, they send the information to the amygdala. It signals to the hypothalamus if it perceives a threat or danger. (5)
The hypothalamus controls involuntary actions, such as breathing, heartbeat, blood pressure, constriction, and dilation of blood vessels and small airways within the lungs. The autonomic nervous system comprises two parts: the sympathetic and parasympathetic systems.
The sympathetic nervous system starts the fight-or-flight response in the body, giving it an energy boost to react to the perceived threat. The parasympathetic system triggers the “rest and digest” response that helps calm the body after the danger has passed.
Once the amygdala sends distress signals, the hypothalamus sends messages to the adrenal glands, which pump the hormone epinephrine (also called adrenaline) through the bloodstream. This causes the heart to beat faster, forcing the blood to the muscles and other vital organs. The pulse increases, blood pressure rises, and the person breathes more rapidly.
Narrow airways within the lungs widen so the person can inhale maximum oxygen with each breath. The brain receives more oxygen, and the senses go onto high alert. The epinephrine causes a release of glucose and fats into the bloodstream, giving the body an extra energy supply.
Some other bodily reactions to the threat are: (6)
- Dilated pupils
- Flushed or pale skin
- Trembling
These reactions happen so rapidly that the person is scarcely aware of them. This fight-or-flight response is so efficient that the person can react to the danger without realizing what they’re doing. Once the immediate danger has passed, the parasympathetic nervous system puts on the brakes and calms the stress response.
The Amygdala Stores Memories and Emotions
The amygdala aids in storing memories of things that have happened and emotions to help identify similar events in the future. Emotionally stirring events create strong memories, and the amygdala plays a vital role in this process.
We have different types of memory active in our brain: (7)
- Explicit memory – memories of actual events that happen to us
- Implicit memory – remembering how to do things – motor memories
- Short-term working memory
Three areas of the brain participate in explicit memory, including the neocortex, the hippocampus, and the amygdala. The amygdala attaches emotional importance to memories. Memories with strong emotions attached, such as shame, grief, love, or joy, become ingrained and difficult to forget.
The amygdala is also involved in making new memories, especially regarding fear. It only takes a few repetitions for fearful memories to take root. The way the amygdala processes fear is relevant to post-traumatic stress disorder (PTSD), which affects a considerable portion of the population due to their careers (police, paramedics, etc.) and other people who have faced traumatic situations.
The Amygdala Plays A Role In Sexual Activity And Libido
The amygdala alerts us to environmental changes detected through our senses. It is also responsible for sexual arousal. Our bodies display some of the same responses to arousal as they do when we sense threats or danger. It elevates our heart rates, we breathe more rapidly, our blood pressure increases, etc. The amygdala also attaches emotional significance to sexual experiences.
The Function Of The Amygdala In Pain And Emotion
The amygdala controls feelings like anger, anxiety, and fear and conditions us regarding punishments and rewards. When we burn our hands, we quickly learn not to touch a hot stove plate. Pleasant experiences will cause us to repeat our actions. (8)
Emotions affect the way we experience sensations. When we are scared, anxious, or depressed, the amygdala processes an injury or illness as a threat and magnifies the pain.
Sometimes we may accuse people of faking pain or illness because one minute, they will be laughing and having fun with a video game. But the next minute, they become overwhelmed and in terrible pain when they have to do something more tedious.
Positive emotions and focusing on the activity can change the intensity of the pain. It’s not an act but how the brain interprets the situation.
Professionals treating people for pain recommend that they get out and see friends, exercise, or meditate to reduce their stress levels. When the world seems a safe and happy place, and you feel more capable and strong, you experience the same sensation but interpret it differently. In other words, the pain diminishes when a person feels happy and strong.
What Happens When The Amygdala Is Damaged?
We can associate functional and structural changes in the amygdala with a range of psychiatric disorders: (4)
- Anxiety disorders, such as PTSD, panic disorders, and phobias
- Autism
- Schizophrenia
- Depression
When the amygdala gets damaged, we can expect to see some of the following symptoms:
- The person is visually unable to recognize objects around them.
- They tend to inspect objects by chewing or smelling them.
- They insist on exploring the surrounding area and overreact to visual stimuli.
- Their expressions of anger and fear are extreme.
- They eat excessive amounts of food, whether hungry or not.
- They exhibit memory problems.
- Aphasia (loss of language and speech).
The Amygdala Hijack
Daniel Goleman first coined the term “amygdala hijack” to refer to an intense emotional response entirely out of proportion to the event. (10)
The amygdala is supposed to warn us that we’re in danger and prepare the body to respond speedily to the threat. But, as the type of threats that we experience have changed to more subtle, psychological ones, this response can interfere with our day-to-day functioning.
Our two frontal lobes are responsible for reasoning. When the amygdala signals to the frontal lobes that we are in danger, they process the information to check if the threat is real and what the reasonable response should be. (11)
If the threat is minor, the frontal lobes will find a more logical solution than the fight-or-flight response. However, if the amygdala takes over, the person overreacts in fear, anxiety, or panic.
Symptoms Of Amygdala Hijack
The amygdala causes a fight-or-flight response when it perceives a threat to its host, real or imagined. The amygdala commands the adrenal glands to release cortisol and adrenaline (or epinephrine) into the bloodstream.
Adrenaline dilates the air passages, sending blood to the major muscle groups, including the lungs and heart. It triggers pupil dilation, improving the person’s vision. Blood sugar levels will spike to provide enough energy to respond to the threat.
If the danger is genuine, these responses are appropriate. When the threat is minimal or imagined, and the person responds similarly, they are experiencing an amygdala hijack. Possible symptoms may include:
- Rapid heartbeat
- Goosebumps
- Sweaty palms
- Inability to think logically
- Aggressive behavior
- Argumentative behavior
- Violence
Hijacking An Amygdala Hijack
Although amygdala hijack is an automatic response, it does not mean that you cannot learn to overcome these reactions. We can teach ourselves to ease the amygdala hijack symptoms and eventually stave them off when we recognize the signs. (12)
When we feel threatened, we should make a conscious effort to deactivate the fight-or-flight response and hand control back to the rational-thinking part of the mind, the frontal lobes.
During the amygdala hijack, take note of your body’s reactions and emotions. The next time you feel this way, acknowledge the response but work to control your reactions. When you are calmer, think about what triggered the reaction and how you felt. Then you can consider some alternative and more logical responses to the trigger situation.
Preventing Amygdala Hijack
Increasing your emotional intelligence is the best way to stave off or prevent amygdala hijacks. This concept relates to a person’s ability to understand and manage their emotions. This will help them alleviate stress, communicate well, empathize, and effectively deal with conflict.
We can increase our emotional intelligence through mindfulness, stress management techniques, and learning coping mechanisms to deal with the amygdala hijack in the moment.
Mindfulness means that you are 100% present in any situation. You are cognizant of your environment, aware of your actions, and not overwhelmed by your circumstances. Research suggests that mindfulness meditation can benefit us in three ways:
- It improves our ability to understand our own emotions.
- It helps us to recognize and appreciate other people’s emotions.
- It assists you in controlling your emotions.
Practicing this daily habit will strengthen your amygdala so that when you are in a stressful situation in the future, you will find it easier to cope with the stressor or perceived threat.
Stress management begins with identifying your stressors and acknowledging when general, everyday stress has escalated to chronic stress. Breathing exercises help with easing the symptoms of an amygdala hijack. Cultivating other healthy habits such as journaling, meditation, and physical activity, also help to prevent these episodes.
There are a number things you can do to cope with an amygdala hijack in the moment:
- Name it. Identify triggers, reactions, and how you can respond better next time.
- Remember the 6-second rule. The chemicals that cause the amygdala hijack take six seconds to activate the attack. Use this time to think about something pleasant to prevent it from overreacting and sending your body into fight-or-flight mode.
- Remember mindfulness. Focus on your environment to take your mind off the stressful situation.
- Breathe. Breathing deeply and slowly calms the nervous system and helps you think clearly and logically.
- Take a moment away from other people to get your emotions under control.
Conclusion
The brain comprises several structures that work together as a powerful and complex organ that controls our marvelous bodies. The amygdala is a tiny but significant part of our brain that plays a vital role in behavior and emotions. It is most famous for the way it activates our fight-or-flight response, which is our body’s protective reaction to perceived threats or dangers.
Of course, our amygdala sometimes overreacts, but we can train our minds to prevent these episodes and differentiate between real and imagined risks. The mind is a powerful weapon and is more than capable of putting the tiny amygdala in its place when it misbehaves!
References
- https://www.simplypsychology.org/amygdala.html
- https://www.britannica.com/science/amygdala
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060967/
- https://www.medicinenet.com/damage_to_the_amygdala/article.htm
- https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response
- https://www.verywellmind.com/what-is-the-fight-or-flight-response-2795194
- https://qbi.uq.edu.au/brain-basics/memory/where-are-memories-stored
- https://www.psychologytoday.com/us/blog/thinking-about-kids/201910/pain-and-emotion-the-role-the-amygdala
- https://en.wikipedia.org/wiki/Amygdala
- https://www.verywellmind.com/what-happens-during-an-amygdala-hijack-4165944
- https://www.medicalnewstoday.com/articles/amygdala-hijack
- https://www.healthline.com/health/stress/amygdala-hijack
