Anxiety and the brain
Brain structure - old and new brain parts
In simplistic terms, the brain is made up of ‘old’ and ‘new’ parts. The ‘old brain’ part, our primitive reptilian brain and our limbic system, developed first. The systems of the old part are located towards the centre of our brains and they drive our survival responses, emotions and instincts. The ‘new brain’ system, the neocortex, is only a couple of million years old. It allows us to plan, imagine, analyse and make judgements.
Old brain responses are faster than new brain responses. They are automatic and immediate and are geared to protect us. They move us away from an oncoming car before the new brain has fully registered that the car is even there.
An important thing to know about the brain is that we are hard-wired for survival and self-protection, not happiness.
The amygdala is part of the limbic system, an old brain system that controls our threat mechanisms, sometimes referred to as the ‘fight or flight’ response. In effect, it works as the body’s alarm system. It scans for signs of danger and, if any are detected, it releases stress hormones (adrenaline and cortisol) which prepare our bodies to fight, run away or freeze.
It is pretty crude and black and white in its reactions. It sees a situation as either safe or not. It doesn’t have the sophistication of our new brain to assess risk. Its job is to protect us. It doesn’t care if it gets it wrong. It makes us respond with fear or anger before the new brain even realises a threatening situation exists.
When our old and new brains are working well together the old brain sees a threat and responds with a shot of stress hormone. Shortly afterwards, the new brain catches up and assesses the risk, checking whether we really need to fight or fly or freeze. So, a car door bangs loudly and unexpectedly. We jump and our heart rate increases. We are about to duck, run, hide, shout, when the new brain realises it’s just a car door, and we let our guard down, laugh it off and move on.
The vicious cycle of the anxiety response
When our old and new minds are not working well together the new brain uses its imagination to create scary possible scenarios and catastrophes, triggering the old brain to activate the fight or flight response when there is no real danger. The old brain becomes stimulated so it starts to see more danger in more situations. Our bodies fill up with stress hormones and we lose touch with the ‘rational’ part of the thinking brain.
The slightest thing makes us jump, we never really feel safe and we can see trouble in every circumstance. We live in the future, worrying about ‘what if’ and we lose the pleasure of living in the present moment. The overload of stress hormones affects the production of protein in our bodies, reducing our metabolism and weakening our immune system. We become physically unwell and start to feel low, maybe even depressed, which increases our anxiety… and so it goes on.
Anxiety becomes an overuse of the imagination. It is a learned habit that can be changed with professional help.
- The Neuroscience of Human Relationships - Louis Cozolino
- The Compassionate Mind - Paul Gilbert
- How to Master Anxiety - Joe Griffin and Ivan Tyrrell
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