Nucleus · one in each half of the brain
Amygdala
Also called Amygdaloid body, Amygdaloid complex
The almond-shaped alarm that spots danger and gives memories their emotional punch.
The amygdala is a small, almond-shaped cluster of nerve cells deep inside each temporal lobe. It constantly checks what is going on for anything important, especially danger, and can set off a fear response before you are even aware of what you saw. It also marks emotional events so they are remembered more vividly. Despite its fame as the "fear center", it also responds to rewards, faces and anything else that matters to you.
Where it is
Deep inside the front part of each temporal lobe, just in front of the hippocampus. You have two, one on each side.
What it does
Spotting threats
It quickly flags anything that might be dangerous, like a snake-like shape or an angry face, often before you consciously notice it.
Learning fear
It learns which sights, sounds and places predict danger, so you can react faster next time.
Boosting emotional memories
During exciting or scary moments, it helps the hippocampus store things more strongly. That is why emotional events are easier to remember.
Reading faces
It helps you pick up emotions in other people's faces, especially fear, and pays close attention to the eyes.
Weighing rewards
It also learns what is good and rewarding, helping to give things their emotional value.
Think of it as a smoke detector for your life: always on, quick to sound the alarm, and sometimes set off by burnt toast.
Inside the amygdala
- Basolateral complexThe amygdala's learning hub: works out what is dangerous and what is rewarding.
- Centromedial nucleiThe amygdala's alarm switch: triggers the racing heart and frozen body of fear.
- Superficial (cortical) nucleiThe amygdala's smell-and-social corner, where scents meet feelings.
Works with
- HippocampusIts next-door neighbor, the hippocampus, records what happened, while the amygdala adds how it felt and how much it mattered.
- HypothalamusIt sends alarm signals to the hypothalamus, which releases stress hormones and speeds up the heart.
- Prefrontal cortexThe prefrontal cortex can calm it down, helping you realize that a scary-looking thing is actually safe.
- ThalamusThe thalamus sends it information from the senses, including, at least in animals, a fast shortcut that lets it react before the cortex has finished looking.
- Locus coeruleusIt can prompt the locus coeruleus to release noradrenaline across the brain, making you more alert.
When it goes wrong
Patient S.M.: life without fear
S.M. is a woman with Urbach-Wiethe disease, a very rare genetic condition that destroyed both of her amygdalae. In studies, she handled snakes and spiders without fear, was not frightened by horror films, and had trouble recognizing fear on other people's faces.
Anxiety and PTSD
In anxiety disorders and post-traumatic stress disorder, the amygdala tends to be overactive, reacting strongly to things that are not truly dangerous.
For learning only, not medical advice. If you have a health concern, talk to a doctor.
Surprising facts
- Patient S.M. did feel fear and panic in one test: when she breathed air with extra carbon dioxide. This suggests that fear triggered from inside the body does not need the amygdala.
- A person whose amygdalae were completely destroyed was found to lack any sense of personal space. In healthy people, the amygdala becomes active when someone stands very close.
- Brain scans show the amygdala can react to a fearful face flashed too quickly for a person to consciously see it.
By the numbers
Where the name comes from
From the Greek "amygdale", meaning almond, because of its almond-like shape.
Learn it in a lesson
- Emotion and rewardFear, drive and the value of things. A short guided lesson in 3D.
Quick quiz
3 questions. Your answers are saved and come back in your daily review.
Which of these is a job of the amygdala?
Show the answer
Spotting threats. It quickly flags anything that might be dangerous, like a snake-like shape or an angry face, often before you consciously notice it.
Spotting threats. It quickly flags anything that might be dangerous, like a snake-like shape or an angry face, often before you consciously notice it.
The amygdala is part of which larger structure?
Show the answer
Limbic system. It belongs to the limbic system.
Limbic system. It belongs to the limbic system.
Which part fits this description? "Like a smoke detector for your life: always on, quick to sound the alarm, and sometimes set off by burnt toast."
Show the answer
Amygdala. It is the amygdala. The almond-shaped alarm that spots danger and gives memories their emotional punch.
Amygdala. It is the amygdala. The almond-shaped alarm that spots danger and gives memories their emotional punch.
These parts now come back in your daily review, just before you would forget them.
Practice these parts in 3DSources
- Neuroanatomy, Amygdala, StatPearls, NCBI Bookshelf
- 13.3 What Is the Contribution of Brain Structures in Emotional States?, OpenStax, Introduction to Behavioral Neuroscience
- Amygdala, Radiopaedia
Spotted a mistake? Tell us.
Explore the amygdala in 3D
Turn it around, zoom inside and see how it connects to the rest of the brain, then test yourself with quick quizzes.
Open it in 3D