Amygdala

Imagine it’s Halloween. You and your friends have just finished up your trick or treating, and you just made it back home to snack on some goodies. Suddenly, your uncle, wearing a scary mask, jumps out from behind the door. Instinctively, you feel a jolt of fear and scream, until you figure out that is just your uncle and laugh it off. You soon forget about the scare and go back to your candy. Many years later however, you can remember that Halloween pretty distinctly, especially how you felt after your uncle’s spooky antics. While your fearful response to your uncle, your memory of the scare, and your desire to eat candy seem unrelated, they can all actually be traced back to one tiny but powerful brain structure: the amygdala.

The amygdala is a part of the brain which is responsible for multiple functions including perceiving threats, finding rewards, and encoding emotional memories. It is popularly known as the brain’s “flight or flight” trigger, which leads to us acting aggressively or fearfully in response to threats. However, the amygdala is deeply interconnected with other systems within the brain which causes it to act as a key middleman in multiple emotional brain processes, such as stress-response, motivation, and decision-making.

In the 19th century a German physiologist named Karl Friedrich Burdach found an almond shaped clump of nuclei near the back of the brain. Based on the Latin word for almond, he appropriately named the clump the “amygdala”. However, after this discovery, the amygdala was largely ignored for nearly a century.

In the 1930s, researchers Heinrich Klüver and Paul C. Bucy reignited interest in the amygdala after performing a dramatic test where they removed a significant portion of several rhesus monkeys’ brains. Without an amygdala, Klüver and Bucy observed that these monkeys acted very strangely. With a newfound confidence, the monkeys would enthusiastically get themselves into dangerous situations, such as approaching snakes and other dangerous predators. This discovery sent academics into a studying frenzy, as they believed they may have found the neurological location of a key human emotion — fear.

By the 1990s, an apparent scientific consensus had been reached: the amygdala was essentially the fear center in our brain. However, in a perfect example of the scientific method, more studies came out to provide nuance to this broad assumption. A key study of a woman with a damaged amygdala showed that she could still feel fear, but she couldn’t recognize fearful faces or other threatening actions. This led to the key reassessment that the amygdala is still critically important in the fear process, but isn’t the full story. The modern conception of the amygdala is that it operates as both a sensor and an alarm bell for threats. In essence, the amygdala develops over time to associate certain contexts, senses, and situations with either threats or rewards. It does this by linking emotional feelings to these memories. For example, you may associate the physical feeling of a candy wrapper with the happy feelings you have during your sugar rush. Or, you may associate the sound of a gunshot with a threat, which acts as a trigger to the rest of your brain to engage in a fear response. When the amygdala is damaged the rest of our brain can still manifest the feeling of fear, but we don’t associate things that should be scary as threats. In the modern view, Klüver and Bucy’s monkeys were not bold due to a lack of fear, they were bold due to ignorance. They weren’t all of a sudden not scared of snakes, they just no longer recognized that snakes eat monkeys.

In such a chaotic world, our ability to recognize threats and seek rewards is paramount. This has long been key from an evolutionary standpoint; we must avoid anything that may endanger our survival and also look for things that help us survive. In the modern day, we no longer have to run from snakes or scavenge for berries, but our amygdala is functionally the same instrument. It is now activated in many important situations where our abilities to weigh risks and rewards can be incredibly important.

The amygdala is a learning instrument which creates emotional associations with the outcome of choices. Due to this form of learning, the amygdala plays a key role in risk assessment. For example, let us say that the first few times you played poker you lost big. If you continue to lose over time, your amygdala begins to associate the pain of losing with poker. Therefore, you may begin to become more risk-averse to avoid losses when playing in the future. On the other hand, say the first few times you play start off on a hot streak, you may begin to associate the pleasure of winning with poker, and you may be more likely to take larger risks in order to feel those rewards in the future. The irrational preferences that form based on this emotional learning culminate in multiple decision-making biases, such as loss aversion, regret aversion, and pessimism bias.

Understanding how the amygdala works is also essential in negotiation. As the amygdala is designed to perceive threats, negotiation can elicit many words, situations, and conflicts that may trigger threat-based responses. This can lead to individuals who you are negotiating with may react emotionally and unpredictably. For example, say a negotiation results in a disagreement which is perceived by the amygdala as a threat. The other individual then begins to feel negatively about the deal, and perhaps begins to feel more risk-averse. In order to combat this, negotiators utilize affect labelling, an empathic technique of where the negotiator vocalizes how the disagreement may make the other person feel. Labelling techniques have been shown to lower negative reactions in the amygdala, which could be the deciding factor of if a deal is made or falls apart.

The amygdala, while heavily studied, leaves a confusing body of work behind. Whether the amygdala plays a sole role in any particular emotional process remains controversial. While we have made significant developments in neuroimaging technology, the interconnected nature of the amygdala with other systems has made it hard to isolate any particular effect. Furthermore, the vast array of subjects it appears to influence underlies its importance in the brain, but also leaves multiple questions to be answered about what else it could be influencing. While the amygdala clearly plays a key role in the overall emotional system, we still have many questions regarding the true power of this mysterious little almond.

Does Emotion Affect Our Ability to Make Rational Decisions?

In this piece, TDL contributor Tiantian Li simplifies the complex neuroscience behind how we make decisions, with a specific insight into how the amygdala interacts with systems within the brain.

Chris Voss: 

Chris Voss is an acclaimed negotiator who had a long career with the FBI. He pioneered theories of tactical empathy and utilized techniques like labelling to change the way we think about negotiation. To learn more about other techniques to improve negotiation, The Decision Lab’s has an in depth analysis of Chris Voss’ philosophy and techniques.