The Science of Being Scared

We have all experienced the unexpected emotion of being scared. Whether you purposefully seek it out by watching a horror movie or inadvertently encounter a mountain lion while on the trail – the physical reaction playing out in your body is the same.

Let’s breakdown what happens in our brains during those moments, whether it be welcome terror or unexpected frights. 

1. SOMETHING WICKED THIS WAY COMES: Fear starts with a trigger, a sensory stimulus of some kind that alerts your brain to a potential danger. The stimulus could be through sight (the nightmare-inducing monster in a haunted house), through touch (a snake slithering over your foot) or through sound (those branches that need trimming scraping across your window).
   
   
   
2. AMYGDALA ACTIVATED: No matter what kind of stimulus you encounter, the thalamus is the first part of your brain to get involved. It’s located at the center of your brain with the very important job of relaying sensory signals to the cerebral cortex. When you encounter any kind of stimulus, a lightning-fast communication from the thalamus to the amygdala happens. 
   
   
   The amygdala is where our brains process what the body has encountered and determines what the reaction needs to be. As part of the brain’s limbic system, the amygdala and thalamus are heavily involved in emotion and the activation of the sympathetic nervous system (SNS) which directs the body’s response to perceived danger. 
   
   
   If the amygdala believes there is a legitimate threat to the body, it sends a distress signal that springs the SNS into action. From here, the question becomes: will you stand and fight or should you run for your life?
   
   
   
3. WILL IT BE FIGHT or FLIGHT? As your brain decides what needs to happens next, you may involuntarily jump or scream, OR, experience a momentary paralysis – literally frozen in fear. This is the fight or flight response turning on, an automatic and involuntary part of our evolution that was at one time critical to our survival. (Think attacks by saber tooth tigers and ambushes by other humans for food or resources.) Because this reaction happens unconsciously, we have little control over our reaction to the initial stimulus and what happens next.
   
   
   
4. LET’S GET READY TO RUMBLE: When your brain believes it may be in danger, it floods the body with adrenaline (epinephrine) which then increases both heart rate and blood pressure. This extra boost causes your heart to pump blood more forcefully to the muscles, which is why you may feel shaky or unsteady when you are scared. This is our ancient caveman brain preparing the body to either run for safety or stand and fight.
   
   
   
5. SIMMER DOWN NOW: Fortunately, unlike our early ancestors, humans today don’t regularly experience the need to fight for our survival. Our brains are pretty quick at determining if we aren’t actually in a life-threatening situation. This is thanks to the parasympathetic nervous system (PNS), the calming force that slows down the flood of adrenaline and helps blood pressure and heart rate return to normal levels. Without the counteractions of the PNS, we would run screaming out of all horror movies believing the axe-wielding murderer was coming after us. 
   
   

Can You Really Be Scared TO DEATH? 

Heart-Stopping Scare

Have you ever said, “You nearly scared me to death!” when someone surprised you? Turns out, that’s not a completely dramatic statement… it is possible to scare a person to death.

How, you ask? Remember how adrenaline floods the body when the SNS activates the fight or flight response? In ultra-large doses, too much adrenaline can be toxic to the internal organs, mostly the heart. While your kidneys, lungs and liver experience damage from the dump of adrenaline, the heart can fail incredibly quickly due to this massive hormone influx and cause death.