FEAR
HOW FEAR HAS KEPT US ALIVE
A pounding heartbeat, sweating hands, and jumpy demeanor—signature characteristics of fear. While not pleasant, this emotion has kept the human race alive by urging us to either fight or run away. But how do our brains do this? It's all thanks to the amygdala.
The structure that drives our survival instincts is surprisingly tiny, occupying less than 0.3% of the brains volume and often described as "almond-shaped". While tiny, that doesn't make it any less powerful; as soon as anything that might be a threat is observed, your amygdala reacts, and signals the brain to be aware.
It triggers sweaty palms, accelerated heartbeat, shortened breath, wide eyes, and a full body chill that freezes you in place. The body is now ready to fight or run away. Along with the amygdala's activation are the secretion of the hormones adrenaline and cortisol, which trigger stress responses like high heart rate and blood pressure that together make up the "fight-or-flight" response.
SO, HOW DO WE CALM DOWN?
Fortunately, there's a "brake" of sorts in our brains that counteracts the amygdala, in the case of a false alarm. The prefrontal cortex, often known for controlling impulses and decision making, receives sensory information while the body's systems are on alert. If, for instance, you find a lit road or some other form of safety, the prefrontal cortex tempers the response and you will begin to calm down.
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WHAT IS THE AMYGDALA?
BUT WHY IS THIS IMPORTANT?
Studying fear can help those with lingering trauma, anxiety, or PTSD. For example, researchers taught rats to associate a tone with a painful shock. The amygdala in the rats were so sensitive that it continued to be active, even after the tone stopped. Through these experiments, they learned what proteins cause this response and how to block the recalling of these learned fears. They realized that blocking the production of the proteins "stathmin" and "transient receptor potential channel 5," causes the rat's fear response to react less strongly. These findings may help develop treatments for those with anxiety disorders such as PTSD.
