If you want to get ahead get a hat. If you want to get a mate get a brain. Today I’m going to talk about why having a brain is really helpful if you have any intentions of moving for some reason perhaps to find food, escape something that things you are food or find that special some one that will make more of you. On the other hand if you plan to stay put and let life come come to you then a brain isn’t necessary and you can get ahead through growing and reproducing where you are or asking for a little help from something that does move. There are situations where you don’t need to move from one location to another but movement to communicate (a place where many of us are finding ourselves these days). A brain is really, really helpful when trying to communicate to others who can recognise the messages.

The Triune Brain – 3 layers

When we start to even think about our brains things can get super complicated super quickly. The reason for the complication is two fold:

1. The wiring is complicated and dynamic: the way that components of the brain are wired together. Although we like to think of the brain as a computer with wiring diagrams associated the reality is a lot messier with parts connecting to one part making it work but another part comes in and stops it then the situation changes and that part is totally short-cutted out completely.
2. The names are horrendous: the study of biology and it’s related subject medicine is as old as the question ‘I wonder what this does?’. This oldest of subject means that we are stuck with an old language that people could agree on a long time ago. We start off with ancient Greece and those Greek philosophers with their theories and their fancy academies and lyceums along with writing. The writing gives many many European dictionary the roots of their words. Having a common root is helpful and one of the reasons for the horrendous words. The Greeks are closely followed by the Italians or more precisely the Romans Latiums (today the region of Lazio) who give us Latin the language of the Roman Empire that spread across Europe 2200 to 1800 years ago. Although the Roman Empire’s armies where defeated their language lived on with those that had the time and opporuntity for reading and writing namely the Christian Church where much of science was written about and shared including biology. Today Greek and Latin make up the vast majority of terms used in biology and give us the fancy names. Heart doctor (heart comes the old English herte and Latin docere for teachers) whilst a cardiologist is from the Greek meaning cardio (Greek for heart) logist (studier of).

Due to this complexity and my inability to remember all the names I’m going to use simple characters and names to try and help you remember. For example when it comes to one of the key aspects of emotion the Limbic system (Latin for border or Edge!) is right up there. One of the key players in the limbic system is the amygdala. What the amygdala does at the moment don’t worry about as I’ll cover this later. For now the amygdala is a girl called Amy D. Gala and she is a highly strung teenager who wants to know everything and will warn the you about danger even if it might not turn out to be true. Amy has a colleague called Hypo Thalamus or Hypo T to his friends and he is the guardian to the body. Again more detail to follow. For now these are just characters that will talk to each other and have their own functions/personalities.

A quick word on models of the brain – their models; not reality

As the brain is super complicated with super hard names to remember many have tried to create a model to make it easier to understand. The creators of each of these models go to some length to stress that these are models not realities. Please bear this in mind as we start with a popular model the triune brain (three parts making one whole) created by Paul MacLean in the 1960s.

Triune Brain (1960, MacLean)

MacLean’s Triune Brain as you would expect from the description breaks the brain into three layers.

Layer 1 – Ancient, Administrative, Not “Reptile” brain

The first layer is the simplest but also the most fundamental as it is the layer that keeps the organism alive as it wonders around the world trying to make more of itself. I’ve very quickly and very likely poorly explained how a single cell can change into being multi-cellular in a previous post where the final stage is one where the organism has a central system to control it’s orientation, and stability of the cells that make it up. The central nervous, or communication, system is where this layer starts with the overall control of the healthy of the body through control of blood pressure, heat (add more, subtract less), primal urges (let’s just call them that for now), overall adminstration of the body.

This layer is summarised into the ancient brain as animals that have been around for millions of years only have a brain with these brain structures and animals that have been around for millions of years are the reptiles hence the “reptile brain”. The brains main function is automatic where it looks after the animal like a life support computer system. You now have a complete and deep understanding of all reptile life and as a bonus all bird life as well as they evolved from those scary or cute dinosaurs millions of years ago.

Hopefully you have picked up on the sarcasm there (a human communication style). If not my apologies but I want to stress, again, that the idea that the triune model of the brain is reality is false – it is a simplification to move us forward. For your understanding we have a part of our brains that regulate base activity and just refer to is the body-control bit of our brain as many of the signals that control the body go up through it from the body or get passed down it from the brain.

From a names points of view this layers is defined as the brain stem which connects the spine cord which gets messages from the body to the first section of brain (don’t get sucked into this at the moment).

Layer 2 – Historic, Emotional, not Mammal brain

Moving in the second layer of the model the “emotional” part of the brain (see why this is a problem? Are all reptile, birds, fish, non-mammals not emotional? How can you tell?). This is where MacLean got his idea of three layers as MacLean was the chap who came up with the idea of region of the brain that appeared to be involved in emotions. The parts of the brain sat between the first layer and the third massive layer which I’ll cover in a bit. As it was in between these two parts of the brain MacLean called it the Limbic System because, you guessed it latin – Limbic is latin for “border” as MacLean found it between those big brain hemi-spheres which you would recognise as a brain from cartoons, and the brain stem, the automatic part defined in the first layer covered earlier.

This layer is seen as the emotional layer as when parts of it are disrupted abnormal emotional responses occur – over reaction or under reaction. The way that I like to thing of emotions are super charges of thoughts into action to ensure you either stay alive or at the appropriate time find love. Emotions are both for internal motivation and external influence two critical factors when it comes to leadership especially when you want to deliberately create followers.

Just to stress, in case you missed it earlier – this just a model to help thinking on this; there is no clear connection between this layer and the lower layer and the upper parts. This layer didn’t pop into existence when mammals evolved to look at cuddly and work in groups (most mammals don’t work in groups) but it evolved over time which many animals have. Having said that mammals do have a couple of additional add ons that reptiles and other animals don’t have: 1) warm blooded – mammals are able to moderate internal temperature rather than have to chill out in the sun to get moving. This allows mammals to live in more conditions than our fish or reptile friends. 2) Directly provide nutrients to babies through milk from the breast (it’s those Italian’s again with mamma meaning breast). This mothering need from mammals does create a dependence between the parent and child that is different to non-mammals and this will mean a different brain structure. However this does not mean that the emotional brain evolved on top of the first layer. I do hope this is getting through.

Layer 3 – Modern, Thoughtful, not just Human Brain

The final layer is the neo-cortex (new [tree] bark because it looks like tree bark?!) which sit on top of and around the other two layers. In humans particulary this part has lots of connections and where there are connections there are decisions and what do decisions make – intelligence (I’ll come to this in a bit). The key part about this layer is that it does a lot of the calm computing and storage for a person and is some times referred as the logical or (get this) executive function of the brain. Whilst it is true that this part of the brain is needed for complex things in humans these complex things are the things that are complex to other animals but not to us i.e. language an other key difference up the evolutionary tree. So if you are reading this your brain is near as dam-it to the your favourite genius it’s just they spent their life doing their thing.

Brain size and mammals: https://www.nhm.ac.uk/discover/news/2021/april/evolving-bigger-brain-not-always-about-intelligence.html

One thing I’ve not mentioned is memory – the recall of information. Needless to say it’s complex but I’ve tried to keep it simple in this quick review of memory.

Now we have a simple model (model – not reality!) to start to put together how we think about the world, what we don’t think (because it’s automatic) and how emotions make us the best and the worst version of ourselves.