Brain biology
The really clever people call it neuroscience – the science dedicated to understanding how our brains work, but we prefer to call it ‘brainy biology’. Whatever you call it, brainy biology is a relatively new science and one that has yet to reveal many of its mysteries This is why we find it so fascinating. Anyway, here is a quick overview of the main bits, including a small surprise.
How many brains does the average person have?
Well, the answer is actually 3, or at least that is how Paul Maclean, former director of the Laboratory of Brain Evolution and Behaviour in Poolesville, Maryland describes it in his ‘triune brain theory’. In explaining how our brains have evolved over the years Maclean argues that our three brains operate like "three interconnected biological computers, [each] with its own special intelligence, its own subjectivity, its own sense of time and space and its own memory".
Sounds very complicated, but if you have ever felt ‘in two minds’ you will know what this is about. For example, ever had that feeling where you really wanted to do something, but you knew you shouldn't? Or when you have felt hungry but managed to think about other things and the hunger has gone away?This is the triune brain in action. Some of our strongest, most basic desires, however illogical, tend to come from more primitive parts of our brain. Meanwhile it is in the newest part of our brains that we evaluate these desires and ultimately choose whether to act on them or not.
So what exactly do all these brains do?
Probably the best way to explain what all of these brains do and how have they have come about is to start with the most ‘primitive’ section of our brain and work out. To do this you need to cast your mind back several million years to when our ancestors were a bunch of lizards sitting around a swamp.
The reptilian brain
This is the brain we share with birds and includes our brain stem and cerebellum. The brain of a swamp lizard is primarily concerned with one issue – survival. In more detail hunger, temperature control, fight-or-flight fear responses, defending territory and reproduction. This is similar in humans, with the reptilian brain controlling the muscles, balance and autonomic functions (e.g. breathing and heartbeat).
The limbic or mammalian brain
We have now evolved out of the swamp and onto the savannah and as a consequence we need a slightly more complicated brain. In particular, we now need to seek out and hunt for food whilst avoiding being eaten ourselves. Thus we come to the part of the brain we share with older mammals like dogs, cats, and horses.
The limbic system comprises the amygdala, the hypothalamus, and the hippocampus and is responsible for memory and emotion. Maclean suggested that what these additional capacities enabled us to do is either avoid pain or seek pleasure. The power of the limbic system is incredible, as I am sure anyone who has ever been ‘totally overcome with emotion’ will tell you.
The Neocortex
From the savannah to the forest and then onto the suburbs. With this wave of evolution our brains need to cope with complex social interactions, advance planning, evaluation of the impact of our decisions on others and problem solving. Thus the neocortex, wrapped around the limbic system, brings the capacity for language and abstract thought and reasoning.
Herein lies one of the great brain mysteries. Why is the human neocortex so big when compared to other primates like chimpanzees when their DNA differs from ours by only 1.6%? Some suggest this is to do with language, but then is language the only thing that has led to humans populating the entire globe, whilst our chimp relatives are stuck in a shrinking rain forest?
What next?
If this has wet your appetite for finding out more about how your brain works then our brainoids is probably for you. If you want to take all of this stuff and apply it practically then perhaps a trip to memory street or learning junction might be more your thing.