Webb Therapy Uncategorized The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The ‘Triune Brain’ theory by Neuroscientist Paul MacLean — an evolutionary perspective

The Concept of the "Triune Brain"

In the 1960s, American neuroscientist Paul MacLean formulated the ‘Triune Brain’ model, which is based on the division of the human brain into three distinct regions. MacLean’s model suggests the human brain is organized into a hierarchy, which itself is based on an evolutionary view of brain development. The three regions are as follows:

  1. Reptilian or Primal Brain (Basal Ganglia)
  2. Paleomammalian or Emotional Brain (Limbic System)
  3. Neomammalian or Rational Brain (Neocortex)

At the most basic level, the brainstem (Primal Brain) helps us identify familiar and unfamiliar things. Familiar things are usually seen as safe and preferable, while unfamiliar things are treated with suspicion until we have assessed them and the context in which they appear. For this reason, designers, advertisers, and anyone else involved in selling products tend to use familiarity as a means of evoking pleasant emotions.

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Polyvagal Theory and Trauma – Dr. Stephen PorgesPolyvagal Theory and Trauma – Dr. Stephen Porges

Stephen Porges, psychiatry professor and researcher, on the polyvagal theory he developed to understand our reactions to trauma:

[Paraphrased] Polyvagal theory articulates three branches of the autonomic nervous system (ANS) that evolved from primitive vertebrates to mammals. First, there is a system known as ‘freeze’, which involves death feigning or immobilisation. Second, the ANS has a ‘fight or flight’ system, which is a mobilisation system. And third, with mammals, there is what Porges calls, a social engagement system (SES), which can detect features of safety, and actually communicate them to another. The SES may also be referred to by some as ‘rest and digest’, which Porges theory suggests is a function of the Vagus Nerve – the tenth cranial nerve, a very long and wandering nerve that begins at the medulla oblongata. When an individual experiences feelings of safety (within an SES state), the autonomic nervous system can support health restoration. In terms of dealing with a life threat, an ordinary person will most likely go into a feigning death, dissociative state of ‘freeze’.

Polyvagal theory in psychotherapy offers emotional co-regulation as an interactive process between therapist and client which engages the social engagement system of both therapist and client. Social engagement provides experiences of safety, trust, mutuality and reciprocity in which we are open to receiving another person, just as they are.

The following extract has been retrived from https://www.theguardian.com/society/2019/jun/02/stephen-porges-interview-survivors-are-blamed-polyvagal-theory-fight-flight-psychiatry-ace

Polyvagal theory has made inroads into medical and psycho-therapeutic treatment, but how should it inform how people treat each other?


“When we become a polyvagal-informed society, we’re functionally capable of listening to and witnessing other people’s experiences, we don’t evaluate them. Listening is part of co-regulation: we become connected to others and this is what I call our biological imperative. So when you become polyvagal-informed you have a better understanding of your evolutionary heritage as a mammal. We become aware of how our physiological state is manifested, in people’s voices and in their facial expression, posture and basic muscle tone. If there’s exuberance coming from the upper part of a person’s face, and their voice has intonation modulation or what’s called prosody, we become attracted to the person. We like to talk to them – it’s part of our co-regulation.

So when we become polyvagal-informed, we start understanding not only the other person’s response but also our responsibility to smile and have inflection in our voice, to help the person we’re talking to help their body feel safe.”

Clink on the link below to hear Dr. Bessel van der Kolk, one of the world’s leading experts on developmental trauma, explain how our long-term health and happiness can be compromised by prior exposure to violence, emotional abuse, and other forms of traumatic stress.

https://youtu.be/53RX2ESIqsM

Are you feeling Restless, Irritable, and Discontent?Are you feeling Restless, Irritable, and Discontent?

I would infer that you may be depleted in some area of your life. Generally, when I am having any of these experiences I can recognise that my basic needs, and possibly even transformative, needs are not met. My basic needs are food and water, adequate sleep, shelter and safety, social connection (belonging), and esteem needs (e.g., self-respect, self-worth, self-competence, mastery and achievement, integrity, sense of freedom and independence etc.). Perhaps only when all my deficiency needs are met, and I’m experiencing dissatisfaction with my growth needs, do I feel Restless, Irritable, and Discontent in this area of my life – however I assume some would argue that if I am feeling that way when attending to my growth needs, then I may have slipped back to Esteem Needs. You can look up Maslow’s Hierarchy of Needs for a visual representation if you like, using a search engine. Below is a GIF that I created to educate people on how we can buffer ourselves to vulnerabilities. It’s very telling to go into the body when we haven’t eat for a while, may be we’re running on caffeine, and you can feel the restlessness in the body. We have to fuel up when we’re hungry to buffer ourselves from becoming irritable and restless. If you’re feeling discontent with life, I would suggest a social activity, play time with friends, working on a project of some kind, or getting involved in your community.