What does your brain do with sensory information it gathers from your body? It puts together sight with sound, taste with smell. Then what?
Once sensory information is gathered from your body, it’s sent to two main destinations, along two different paths: the high road and the low road. The high road leads to your prefrontal cortex (PFC) and Worry Loop, the low road leads to your amygdala and Fear Circuit.
In the second post of this series, “What is Anxiety?” we covered that anxiety is made up of two basic components: worry and fear. Worry and fear come out of two very different parts of the brain.
We’ve talked previously about your Worry Loop and described that aspect of anxiety which is based in worry and ruminations about the future. The other path in the brain is your Fear Circuit: the part of your brain that feels anxiety as fear, panic, and phobia.
While your Worry Loop’s job is to think, plan, and act, the purpose of you Fear Circuit is to keep you alive in imminent danger.
Fear is the emotion, sensations, and responses of the brain and body that help you suddenly cover your head and duck when a baseball comes flying at your head. Fear is what enables you to go from deep sleep to suddenly alert, awake, and out the door when the fire alarm goes off in your house.
The purpose of fear is to keep you alive in imminent danger.
Your amygdala is a small, almond-shaped part of your brain deep in your limbic system. Your amygdala is the core of your Fear Circuit: the parts of the brain and the nerves that trigger the body’s fear response.
In fact, the most common metaphor for the amygdala is a smoke detector. We call the amygdala the smoke detector of the brain because it does the same thing as the smoke detectors in your home. While you go about your normal day, your amygdala is screening your basic senses, your thoughts, and your memories for current threats.
When it senses a threat, it sounds the alarm in seven different areas of the brain, quickly taking your attention away from that conversation with a coworker and turning it to that car approaching too fast. This response that turns your attention away from everyday goings-on to an imminent threat is called the fear response.
The High Road and the Low Road
Your whole-body fear response is intended to save lives or prevent harm. So, it happens fast. Two signals are sent from your thalamus. We called your thalamus Grand Central Station in a previous post since it organizes all the sensations coming up from your body.
Your thalamus signals both your prefrontal cortex (PFC) (the thinking part of the brain) and your amygdala (the smoke detector). But the signal travels faster to your amygdala by a few milliseconds.
The trip from your thalamus (Grand Central Station) to your amygdala (smoke detector) is just a little faster than the trip from your thalamus (Grand Central Station) to your PFC (thinking, conscious part of the brain) involved in your Worry Loop.
We call the path from your thalamus to your amygdala “the low road” because it’s quick and dirty. It acts on a rough sketch of the information coming into your brain. The path to your thinking brain is “the high road” because it sends a better synthesis of all the information going on, but it takes longer to get there.
A lot of the time you end up talking yourself down from a fear response when you realize there is no actual threat.
To understand the difference between the low road and the high road, think of the quality of the information sent by the low road to your amygdala as looking like 1930s black and white film. It’s grainy and rough, and you sometimes can’t quite tell what’s going on.
Your amygdala receives and acts on the low road’s grainy footage. Later, the high road gets its information to your thinking brain in a version with 4K resolution and surround sound.
The thinking brain might come to a different, more accurate answer about whether a baseball bat is being used for sport or as a weapon. But it gets that high-res image a split second after your amygdala has already responded to the low-res version. A lot of the time you end up talking yourself down from a fear response when you realize there is no actual threat.
Why You Have Two Paths
You need both the low road and the high road. The difference between the low road and the high road can be seen in everyday life. This is what you see if you’ve ever dropped a hammer and jumped back to pull your feet out of danger before you even consciously realized you dropped the hammer. Your amygdala told you to step back before your thinking brain even noticed the hammer.
Your conscious mind plays catch up whenever your fear response is triggered. I recently dropped a teabag on the floor and pulled my foot back just as fast as if I’d dropped a hammer. By the time the teabag hit the floor, my conscious mind realized there was no threat, but it would have been too late if it had been a hammer and I hadn’t reacted.
We’ve all had plenty of times where the low road to the fast-acting amygdala has saved us from harm. And we’ve also had plenty of times where the amygdala wrong and we acted fast, then realized there was no threat.
Can you think of any such situations in your life?
Would you take a moment to send some gratitude to your fast-acting amygdala, that works to keep you safe and sound? Would you send some appreciation to your prefrontal cortex, that gets a clearer picture of what is going on around you?
Most of all, see if you can find compassion for yourself for times you’ve reacted fast in fear only to find out a fraction of a second later there was nothing to be afraid of.