The danger has passed. What happens next?
OK, the threat and the stress is over – it’s time (in theory), for calm to return.
Our “stress chemical fueled”, supercharged body has done its job and the threat has now passed – we’ve escaped the wild animal, we’ve jumped out of the way of the speeding car, we’ve delivered that critical client report, made-up with our partner after the argument ….
With the threat and stress now over, our body is designed to return to a state of homeostatic balance.
Our eyes and ears capture the sight and sounds of the escaping wild animal (or the car driving away) and once again, sends this information to our amygdala for processing.
Our brain sends the message that the threat has passed and it’s time to switch-off the Stress Engine and switch-on, the Relaxation Engine
Our amygdala interprets this and in turn, tells our hypothalamus that yes, things are OK and the threat has passed.
Our hypothalamus then tells our autonomic nervous system to “switch on” our calming parasympathetic nervous system (switch-on our Relaxation Engine), and so “switch-off” our sympathetic nervous system/Stress Engine and stop the flow of the dangerous stress chemicals that have been flowing through our body.
The activation of our parasympathetic nervous system, triggering our body’s opposite “rest & digest” response, acts like a brake to the stress response, to calm our body after the danger, and return it to balance.
Our parasympathetic nervous system acts like a brake, stops the flow of stress chemicals and acts to calm our body.
Our parasympathetic nervous system/Relaxation Engine uses the neurotransmitter acetylcholine to communicate with the organs throughout the body, switching-off our Stress Engine, halting the flow of the stress chemicals, with the effect that:
- Our muscles relax;
- Our heart rate drops;
- The bronchial tubes in your lungs constrict, slowing our breathing rate;
- Our saliva increases, digestive enzymes are released and blood vessels to our GI tract open, helping to assist digestion and absorb nutrients;
- The pupils in our eyes constrict and return to normal;
- Our urinary output increases,
And our body returns to a state of homeostatic balance, free of the effects of the stress chemicals.
So, doesn’t a supercharged body sound like a good thing?
But surely, a supercharged body, that is switched on and off – optimized and fueled for almost superhuman performance – must be a good thing??
Well – yes and no – The positive effects of stress are a balance
Stress is not necessarily a bad thing.
When we have a single high stress, high intensity, task or activity that we need to complete – like escaping a wild animal, or jumping out of the way of an out-of-control car, or standing up in front of an audience and delivering an important presentation or speech, or focusing all our efforts to complete an important client report that has a non-negotiable deadline!
As we’ve shown, our stress response is critical to our ability to escape a dangerous situation, or perform under pressure, to deliver an urgent report, or give a presentation in front of a large group.
There are numerous examples of emergency service workers, soldiers, even ordinary citizens, who have performed seemingly superhuman feats, when confronted with a life threatening situation.
Independent of the health impact of exposure to long term stress, we also need to recognize that our performance under even short term stress is a balance.
As we’ve seen, we need physical and/or psychological stimulus to prepare our body for the highest level of performance – our body experiences physiological changes in response to stressors, our alertness increases and our attention sharpens.
So, as our stress and anxiety levels rise, so does our efficiency and performance – however, only up to a point!
The most famous research in this area, performed by psychologists Robert Yerkes and J. D. Dodson, resulted in the “Yerkes-Dodson Curve” below, which showed that as stress continued to increase, beyond the optimal point, eventually performance and efficiency declined.
So stress can be a good thing, when it allows us to tackle a difficult (or dangerous) task, and once the task has been completed, we are allowed to return to a state of calm.
However … stress can be a very bad thing, when our Stress Engine does not switch-off and our body never returns to calm