There's a man with a gun over there, a tellin' me I got to beware."
-For What It's Worth-Buffalo Springfield
Setting: Amygdala Alert Response Defense Activation Center (AARDAC)
Location: Temporal lobes deep inside Shaun's brain
Date/Time: 07/06/2014/1452 hrs.
Technicians sitting in darkened room in front of panels illuminated by glow of screens from vast array of computerized sensor detection instruments.
Tech #1: " Somatosensory system registering heat rising from roadway."
Tech #2: "Auditory system picking up heavy traffic sounds."
Tech #3: " Visual cortex reporting overturned trash barrel alongside road."
Tech #4: " Olfactory center detecting rotting garbage odor."
Threat Assessment Center (TAC): "IED! Activate defense systems!"
Adrenal glands: "Cortisol and adrenaline released."
Heart: "Rate increased,blood flow redirected to muscles and limbs."
Lungs: "Respiration and oxygen intake increased to max level."
Prefrontal cortex: "False alarm, stand down, false alarm, stand down!"
Control Center: "Shutting down all defense response systems. Return to normal operation following recovery delay."
Iraq, Afghanistan? Could be but let's look at what's actually going on here. Shaun,a Marine vet who served four tours in Iraq and Afghanistan, is riding his motorcycle down a neighborhood street in his home town, the war eight years in the past. It's a bright, hot sunny day when he notices an overturned trash barrel along the curb. A dog is pawing through the garbage and suddenly the smell of rotting meat wafts into his nostrils as he rides by.
Instantly his amygdala receives all this sensory input and goes into full defense mode. And in milliseconds Shaun is transported back to Iraq when he was in an armored vehicle that was blown up by an IED hidden in a pile of trash alongside the road. Without thinking he accelerates, swerving wildly past vehicles in front of him, narrowly missing an oncoming school bus.
So what just happened here? People who have experienced a traumatic and sometimes life-threatening event, combat, shark attack, motor vehicle accident, assault, often find themselves re-experiencing the event when certain stimuli or triggers activate the amygdala defense system. This is one of the things that happens in PTSD when people experience flashbacks. Here's how it works:
Remember, the amygdala's primary function is the survival of the organism, in this case Shaun. It's the watchdog of the organism and its responsibility is the formation and storage of memory associated with emotional events.. It collects and stores as much sensory input such as sight, smell, sound, tactile as it can from the traumatic event. And it has a remarkable memory and can store data for a lifetime. So some time down the road, maybe years later, when all or some of these triggers occur, our friend the amygdala swings into action. Forty-five years later certain smells still instantly transport me back to Vietnam as the olfactory sense (smell) is the most powerful activator of memory.
And it doesn't differentiate between real threat and something benign such as an overturned trash barrel. There's not time. It operates under the better-safe-than-sorry principle when survival is at stake and initiates a series of emergency reactions before we're even aware of the trigger. It's the job of the pre-frontal cortex to objectively assess the threat and then send the signal to shut down all activated defense systems.
But information from the senses reaches the prefrontal cortex milliseconds later as conscious or rational thought always lags behind the emotional reaction. Only then does Shaun realize that it's only an overturned trash barrel and the response de-escalates. But it still takes awhile for all those chemicals to metabolize and for calm to return.
So the amygdala is our friend and faithful watchdog whose purpose is to sense threat before we do and keep us safe from danger. It doesn't get it right every time, in fact it's batting average is probably pretty low, but it knows it's better to be safe than sorry. It's why we're still here four million years later rather than sabertooth tiger dinner.
Next Time: ATTACK OF THE PERFECTIONISM DEMON