My recent foray towards the humanities exposed me to the William James quote above which got me thinking on a recent holiday.
On this holiday I found myself on the Island of Capri (I was just there, it wasn’t some sort of spiritual epiphany). The Island has two towns, Capri and Anacapri, the later been known for its chairlift to the top of the Island.
I don’t really do heights but to put that into context, I took up skiing for my Duke of Edinburgh because I knew if I got good enough I would have to tackle cable cars and chair lifts and I took up amateur dramatics because I hated public speaking so, don’t like things but definite tendencies towards feeling the pain and doing it anyway.
And so, having declared that I was not going to ride this chairlift, I found myself at the base station, ticket in hand and my fit bit telling me that my resting heart rate was 110 – it’s usually low 60’s.
It was at this point, in an effort to think about something else, that I was reminded of the blog post title, and my favourite derivation of it ‘Do we stop playing because we get old or do we get old because we stop playing?’
Was my heart rate 110 because I was scared or was I scared because my heart rate was 110.
Having had a trip the previous year to Adelboden where we went on half a dozen cable cars and my pulse was over 100 for the whole day, I can confirm that it makes you feel very ill and you start to worry that something serious is going to happen. That is the start of a vicious cycle that leads to a full blown anxiety attack. You don’t want to go there when you are hanging in a chair from a cable all on your own.
So, what was happening? I was perceiving the chair ride as a threat to my life and limb and so my body was going into ‘fight or flight’ mode.
The second I thought about the chair lift, I was hijacked by my amygdala. A small almond shaped part of my brain which posed the eternal question, ‘Should I stay or should I go now?’ (You will remember the tune to the well known song.)
Because either option is going to require energy, the amygdala kicks your adrenal glands into action to produce adrenaline. (They are also called your suprarenal glands because they sit on top of your kidneys and adrenaline is also called epinephrine but that doesn’t sound so logical.)
It isn’t that simple though, far from it. Your amygdala tells your hypothalamus that there is cause for concern. This then produces a hormone called Corticotropin releasing hormone (CRH) which acts on the anterior (front part) of the pituitary gland. This is only a few centimetres away from the hypothalamus but they communicate by releasing the hormone into the blood stream – so now everywhere knows there is cause for concern.
The anterior pituitary responds to this by releasing adrenocorticotropic hormone (ACTH) which tells the adrenal glands to produce adrenaline. This whole network is called the Hypothalamic-Pituitary-Adrenal network or HPA for short (because everyone has to get a mention).
The end result is that your body is flooded with adrenaline along with steroids, corticosterone and testosterone. Your likely to be more snappy and aggressive (just speak to anyone who has shared a cable car with me), your heart rate will increase, you will sweat and feel sick.
This whole process takes milliseconds. It has developed so that in situations of real danger you are ready to act. A chair lift is not a real danger. Most of our stressors today are not real dangers. Robert Sapolsky has written a great book on it called ‘Why zebras don’t get ulcers’. You should read it.
Standing there waiting to be scooped up towards oblivion the summit, I was able to pull my frontal cortex into play, the part of my brain that had been bypassed; the part responsible for rational thought.
There must have been a moment when my brain decided I needed to be scared and yet I didn’t have the symptoms. The symptoms were caused by my reaction to the chemicals that my brain had caused to be released. My brain had decided I needed to be ready to act and that had caused me to be scared. (This encroaches on whether I am more than my brain – which is a whole different blog post).
Speculating on this got my pulse down to 80 and saw me arrive at the top of the Island.
Weirdly I don’t get the same reaction on the way down where the risks are exactly the same – go figure. Neuro is weird!
This art by @DrRabbitHeart sums up the process. Thanks for letting me use it!
anatomyfundamentals.com 