The Anatomy of Fear
By the time our ancestors were roaming the great savannas, alternating between chasing prey and being prey, their systems had already adapted to face the harsh environment, according to Rick Hanson PhD, author of Buddha's Brain: The Practical Neuroscience of Happiness, Love, and Wisdom.
Today, those ancient adaptations show up in the most peculiar ways as we constantly hijack a system built for times long ago. Getting cut off on the highway might not seem an awful lot like being chased by a lion, but to the brain’s subcortical structures, it’s pretty much the same deal.
Hanson explains how it all works.
As you feel yourself careening across a lane of traffic, your brain sounds the ancient ‘lion alarm,’ and begins to prepare for battle. First, stress hormones like Epinephrine kick your heart rate up and Norepinephrine increases blood flow to bring your largest muscles online faster. Your pupils dilate to take in more light for enhanced visibility, and your bronchioles expand, boosting lung capacity for punching and speed.
Another stress hormone called cortisol jumps in to suppress your immune inflammation warning system, just in case you happened to be wounded. The hippocampal system, which normally does its part to keep the cortisol level of the amygdala (the brain’s fear center) under wraps, takes a proverbial step back and lets the amygdala ratchet up, which drives more cortisol into your system, in effect supercharging your blood, much like adding octane to your vehicle’s gas tank.
The system that governs reproduction essentially turns off, because that’s not something that you’re likely to be thinking about at the moment, and your digestive system also goes into hibernation, allowing the body to redirect energy and blood flow as needed.
All of this signals your amygdala to go on a higher level alert; this system, which normally monitors threatening information, turns up the heat on your emotional thermometer and moves the needle from stress to fear/anger in order to raise your level of intensity commensurate with a struggle for life or death.
Your prefrontal cortex, the home of reason, speculation, planning and assessment gets hijacked by more primitive systems like the amygdala and takes a backseat, fundamentally turning the keys to your body over to your reptilian brain. Not a whole lot of contemplation going down when you’re in “kill or be killed” mode.
There was a time when the primitive elegance of this system made sense. But that was a long time ago. Today a whole host of activities, from being cut off on the road to a bad email from your boss, can trip the ancient survival system.
Many people find it difficult to deactivate the stress switch. Hanson teaches that practicing mindfulness and meditation are ways to help keep the brain from prematurely sounding the alarm bell all day long.
Sadly, for all too many people, there is a lion lurking around every corner.