If you come across the terms “reptilian brain” or “mammalian brain”, use them insofar as to understand the fight-or-flight vs. rest-and-digest modes (sympathetic vs parasympathetic nervous activation). By embracing the brain as an adaptive system instead, we welcome the bigger premise that we are in charge of, and can make a positive difference to our health.
inaccurate 1960s theory
If you geek out on brain science, you may come across the terms “reptilian brain” and “mammalian brain”. They were coined as part of a proposed model in the 1960s called the “triune-brain theory”. Neuroscientists have since debunked that theory.
Our brains did not grow new layers over older structures. Biologists concur that the brains of all animals (land, sea, sky) have the same basic anatomical regions: forebrain, midbrain and hindbrain – just in different proportions. Animals (including dogs and goldfish, and not just humans) have been observed to be capable of deciding between actions and consequences.
explaining why we react
Some mindfulness materials may use the triune brain model to help describe a threatening event: our “lizard brain” hijacks our thoughts, words and/or behaviour – instinctively prioritizing protection. Should we intentionally bring our awareness back to the more “developed” mammalian brain, we calm the amygdala down.
This old model graphically compares a skittish lizard vs. a composed homo sapien. However, I’m learning from the latest reports that we feel calmer because we are engaging a different, wider pattern of neural activity – the well-documented autonomic nervous system (ANS). There is no “lizard” part of the brain, no “reptilian” switch to turn off.
updated brain description
Neurobiologists observed that our brains are adaptive. The brain constantly makes predictions about future scenarios, with the objective of maintaining a state of balance (homeostasis internally and allostasis with our surroundings). So our brain is essentially and continually seeking to optimise for the future.
E.g. I feel angry. I imagine the person making me upset does not respect me. I raise my voice as a reaction to be heard, predicting that I will gain back the reverence. This is normal human behaviour. Rewind. Choosing a mindful approach instead, I notice this emerging emotion, familiar that it is just a shadow of my insecurity. Predicting an outcome where I don’t say something I will regret, I choose not to engage. I allow the tension to ease off. Balance returns.
so what do I do?
The ongoing practice for a mindfulness practitioner is:
- In a difficult circumstance, can we choose to adapt positively?
- If we had reacted negatively, what can we learn from it?
To paraphrase one of my teachers, if in the past we had gotten angry ten out of ten upsetting situations, and moving forward, we observed only losing our cool nine out of ten times, then we have successfully applied the mindfulness touch.
May your brain remain adaptive as you continually strive to be your better self.
