Our brains can be divided into three parts (hence the term, triune brain) as follows:
1) Reptilian Brain (also called the brain stem):
This part of our brain is the oldest in evolutionary terms, and, therefore, the most primitive. It reacts to events instinctively without conscious deliberation ; in particular, it gives rise to :
– our immediate biological sexual responses
Essentially, then, this part of our brain is responsible for our survival. If we feel seriously threatened, it over-rides the two other parts of our brain (see below).
Also, if we drink too much, the influence of the reptilian brain becomes more dominant, as alcohol can significantly reduce the activity of the two (mammalian and neomamallian) higher parts of the brain; when drunk, therefore, we are more likely to get into fights or indulge in promiscuous and/or unsafe sex.
2) The Mammalian Brain (also called the limbic system or midbrain)
This was the second part of our brain to evolve. It is involved in :
– the generation and experience of our emotions
– memory and other aspects of learning
3) The Neomammaliam Brain (also called the neocortex) :
This is the most recently evolved part of our brain and is involved with :
– decision making
– conscious control of social behaviour
– speech / writing
– purposeful (as opposed to instinctual) behaviour
– planning for the future
– expression of e Triune Brain :
Which Animals Do We Share These Three Parts Of Our Brain With?
1) Reptilian Brain :
We have this part of our brain in common with crocodiles and snakes
2) Mammalian Brain :
We have this part of our brain in common with cats and dogs
3) Neomammalian Brain :
We have this part of our brain in common with chimpanzees and gorrilas.
What Has All This Got To Do With Borderline Personality Disorder (BPD)?
If we have suffered significant childhood trauma, it is possible that the physical / biological development of our brains has been adversely affected. And, if we are unlucky, and, especially, if we have a genetic susceptibility, we may, as a result, go on to develop borderline personality disorder (BPD) as adults.
Indeed, a leading theory relating to BPD, is that the brain has developed in an atypical and detrimental manner in connection with our ability to regulate our emotions and control our behaviour.
As such, the neomammalian part of the brain (responsible for conscious control of behaviour, decision -making, planning and logic) may be underactive.
The more primitive parts of the brain (the reptilian brain and the mammalian brain) may be overactive and too easily to being triggered (e.g. even a very small threat may trigger great activity in the reptilian part of the brain which is responsible for the fight or flight response.
This combination of faulty brain areas can mean that individuals with BPD experience emotions, such as anger and fear, far more frequently, and far more intensely, than the average person; and, also, have a significantly impaired ability to exercise control of their behaviour, make sensible decisions, plan for the future and think rationally.
How Can BPD Sufferers Gain More Control Over Their Feelings And Behaviour?
In order to gain greater control of their lives, it follows from the above theory that it is necessary for BPD sufferers to make the neomammalian part of the brain more dominant and to quieten the more primitive brain areas.
Research shows that an effective way to do this is to practice mindfulness meditation – if possible, on a daily basis.
David Hosier BSc Hons; MSc; PGDE(FAHE).