The Amygdala – The Fear Centre of our Brains
This week we are going to start looking deeper at the key parts of the brain used to process our emotions starting with the amygdala.
The amygdala is the part of our brain that learns what to fear.
When we couple a neutral stimulus (like a sound) with something that normally causes us to be scared (like an electric shock), then over time, we learn to fear the sound.[i]
When mice have a lesion on their amygdala, they do not show an ability to learn this fear response. They still fear the electric shock, but they do not learn to fear the sound. [ii]
In this way, the amygdala has been key to our survival.
When we feel fear, the amygdala automatically activates our fight-or-flight response. It signals the release of hormones to fight the threat or run away.[iii]
It does this before we are even aware of the threat. Information from our senses go straight to our amygdala before we consciously process it in the thinking brain (cerebral cortex). But providing this shortcut it lets us respond to danger without any thought.[iv]
For example, if you are walking along and catch a glimpse at snake darting out toward you, you want to be able to immediate react and not spend time wondering if it is a snake and if it is a threat!
Amygdala Hijack
While this function of the amygdala is useful for when a deadly snake is coming out at you, it can be overactive on today’s stressful world. It an respond to daily stress in the same was as a physical threat, like a snake and trigger your fight-or-flight response.[v]
Some studies have also suggested amygdala is key to social interaction, others have linked it with aggression and others have connected it to sexual orientation.[viii]
Conclusion
The amygdala is key to how we learn what to fear. When it detects a threat, it activates our fight-or-flight system to either runaway or fight the threat. Sometimes this is maladaptive in today’s stressful world. However, more recent research has found that the amygdala is not just about fear and may also help us label positive emotions when we are rewarded. Additionally, emerging research has also examined its links to social interaction, aggression and even sexual orientation. There is still so much to learn.
[i] Ward, J. (2015). The student's guide to cognitive neuroscience. Psychology Press.
[ii] Ward, J. (2015).
[iii] Ward, J. (2015).
[iv] https://www.neuroscientificallychallenged.com/blog/know-your-brain-amygdala
[v] https://www.healthline.com/health/stress/amygdala-hijack#takeaway
[vi] https://www.livescience.com/amygdala.html
[vii] https://www.neuroscientificallychallenged.com/blog/amygdala-beyond-fear
[viii] https://www.neuroscientificallychallenged.com/blog/amygdala-beyond-fear
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