All Magic Comes at a Cost.

Like most things in this life, anything worth having comes at a cost.  This rings true in the context of the fight or flight response.  This subconscious survival response has played it's part in keeping us and our ancestors safe through time but there have been some costs to our health, both physically and mentally.  We will take a look at both in this post.

As we have already seen, some of the feats the human body and perform when this response kicks in are quite breath taking, and often times unbelievable.  The increased speed, strength, endurance and pain resistance that the epinephrine induces comes with a pretty big side effect.  Like any high performance machine, the body can only work at this turbo boosted level for a limited period of time.  Once the immediate danger has passed or the large amounts of glucose released into the system are used up, you are left feeling an extreme level of exhaustion.  You're likely to feel light headed and barely able to move or exert any force.  This is the dreaded "adrenaline dump".

The effects of an "adrenaline dump" are quite temporary, with bodily service resuming once normal levels have been restored.  A sports drink containing simple sugars can help to replenish the vast amounts of glucose used up and increase recovery

Perhaps the most damaging effect that this survival response can have on the body is its role in the anxiety disorder PTSD (Post Traumatic Stress Disorder).  PTSD is a disorder that can effect people that have gone through times of extreme stress and trauma such as war and natural disasters.  PTSD is caused when the sufferer mentally re-lives the experience causing their fight or flight response or parts of it, to be constantly switched on. The effects of this can be crippling, not only mentally but physically.  Nightmares and phobias of places that trigger memory of the trauma are common, there is also the possibility for the loss of emotion too.  Physically, hyperarousal often manifests and leads into loss of sleep as well as the possibility of hypervigillance.  Prolonged activation of the response can also lead to complications with the sufferers immune system.

 

 Although this condition has been around a long time, relatively little is known of it and we are still searching for a better understanding.  At the current time, the best responses to patient recovery have come through group and individual psychotherapy.  There are also a few pharmaceuticals on the market that can help ease some of the symptoms.

• http://www.ptsd.va.gov/
• Allen D. Leth, Jr. (2009). "The relationship between Post Traumatic Stress and physical fitness and the impact of Army fitness policy on Post Traumatic Stress prevention". U.S. Army Command and General Staff College.

 

Mind Control

So far we have been focused on the physiological mechanisms and effects of an adrenaline surge, this post is going to take a look at how the brain deciphers the signals and activates the fight or flight response.

The entire fight or flight process is a complex one that takes place in our subconsciousness.  For ease of explaining the process I will break it down into steps.

1. Sensory information is taken in by the eyes, ears and body, and directed towards the brains Thalamus.
2. Sitting atop of the nerve stem in the middle of our brain, the Thalamus is the brains nerve center.  From here the sensory information is split and routed in two directions.
3. One destination is the frontal cortex, located in the neocortex.  This area of our brains is what separates us from the chimps, it is where all our higher mental functions take place.
4. The second destination is the Amygdala, located just in front of the Thalamus, this is the brains threat evaluation center.  As the sensory information flows into here it is evaluated for any signs of danger. 
5. Before a response can be initiated the Amygdala will project the information of the perceived threat to the neocortex.  It is here that our higher mental capacity analyses the threat in greater detail and decides if there is threat or not.  If the coast is clear it will tell the Amygdala to "stand down" and not initiate the reaction.

As well as threat perception the Amygdala is also where our brains learn emotional association.  For example, being stung by a bee as a infant.  Whilst consciously we may not remember the incident, the Amygdala will store the information that involved so that as an adult, the sound of a bee buzzing past your ear will illicit a fearful response.

With this system being kept in check by the neocortex it is understood that situational training can condition the mind to react to stress and fearful situations.  A key skill for a soldier in combat where the difference between fight or flight can mean safety or mortal danger.

•   LR Mujica-Parodi, HH Strey, B Frederick, R Savoy, D Cox, Y Botanov, D Tolkunov, D Rubin, J Weber: Chemosensory cues to conspecific emotional stress activate amygdala in humans. PLoS One 2009, 4:e6415. 
• LeDoux, J. E. The Emotional Brain: the Mysterious
  Underpinning of Emotional Life (Simon & Schuster, New
  York, 1996).