Understanding the limbic system versus the neocortex and why most of us live our lives as smart monkeys rather than human beings
Up to now I’ve presented lots of ideas about why this and that, but mostly from a wider societal viewpoint, with lots of references to the idea that we might be victims to our own brain architecture. I’ve offered some ideas for learning to “hack” these systems (here) and to think more like a “systems admin” for managing the analogies of files and the operating systems within our brains (here). In this post I’d like to talk a lot more about the way our brains are structured, and why that’s a problem for most humans.
Let’s quickly revise neuroanatomy 101. Our brains are amazingly complex organs – some say potentially the most complex structures in the universe – that have evolved over billions of years. As amazing as they are, the evolution of the brain has meant that, in its current form, it still contains all the previous versions of itself. It’s a bit like having a computer that is continually upgraded, but still runs all the earlier versions simultaneously, some of which can interrupt or even screw up current functioning. I’ll elaborate…
So, the most basic part of our brains (and the first part to evolve) is the brainstem, sometimes referred to as the reptilian brain (because it’s basically what lizards have), and which controls a lot of our automatic functions (such as breathing and heart rate, as well as basic arousal). For the most part, the brainstem functions without conscious intervention, and is largely outside of conscious control (we can learn to control aspects but it takes work). Sitting on top of the brainstem is the limbic system (otherwise known as the midbrain, and often referred to as the mammalian or monkey brain). The limbic system evolved during our early mammalian state and is largely responsible for day-to-day survival. Put simply, this section houses two main functions: fear and avoidance centres to keep us away from dangerous things, and a pleasure centre to help us repeat behaviours advantageous to survival. Last to evolve was the neocortex, the crinkly bit on the outside of our brains that is responsible for many things, but which allows us to think rationally, be self-aware, plan, imagine, love, be compassionate, be able to speak and read, and so on…
This synopsis is, of course, a massive oversimplification. I haven’t even begun to talk about localisation and specialisation of brain regions, or the hemispheres, or various lobes. Other people have done this a lot better than I can – if you want to know more, a quick search on neuroanatomy will yield huge amounts of info…
Here’s the problem: it’s like we have an inner monkey that hasn’t been brought up to date on the modern world. This monkey tries hard to go about its task of keeping us safe and helping us breed. But it isn’t capable of understanding the really complex information that our neocortex processes and generates – so it just keeps doing what it was programmed to do: keep us alive in (what it perceives to be) a dangerous and threatening world. Let’s face it, for most of the last several million years, humans and our ancestors spent most of their time trying not to be eaten. It’s handy, therefore, to think of this part of the brain as a “don’t eat me” engine…
Why is this a problem? Because this part of the brain is really good at grabbing our attention and modifying our behaviour accordingly. It had to be, because the last thing you want, in a system that evolved to keep us alive, is the risk of it not working when we need it. In other words, this system is constantly vigilant and works around false positives – it’s much better (from a survival perspective) to jump at something in the corner of your vision or when you hear a rustling above you, than to get eaten by a sabre-toothed tiger. So, we have a highly active system that’s always on, protecting us from tigers. Except that these days, there aren’t many tigers around (literally and metaphorically) – we just don’t need it any more.
There’s another thing you need to know about the limbic system: it’s hardwired around pleasure – a major part, called the mesolimbic dopamine system, delivers pleasure in the form of a neurotransmitter called dopamine. Again, from an evolutionary perspective this makes a lot of sense: we want to repeat behaviours that increase our chances of survival or reproduction. When this system evolved there was a pretty narrow range to choose from: sex (to reproduce), food and water (to provide nourishment), companionship (to provide safety in numbers), not much else. So the system is pretty simple. In the modern world, however, we’re bombarded by things that activate our pleasure centres, and it’s easily fooled into thinking that all of them are good for survival and worth repeating. For example, cocaine works by increasing dopamine levels by about 100 times more than sex. As far as your limbic system is concerned, cocaine is 100 times better for survival than sex, so if we use cocaine it can modify our behaviour through reward so that we work very hard to seek out and consume more cocaine (this is addiction). Obviously, cocaine is not good for survival, but it is one of thousands of substances, behaviours and experiences that can fool the pleasure centres into thinking that they are.
This system flaw is a big problem for us because, like the fear centres warning us to stay away from things that it believes are dangerous (when they’re not), the pleasure centre tells us that activities that are actually dangerous feel both good and right. That is, in the modern day, our limbic systems can actively work against us, convincing us that safe things are dangerous and that dangerous things are safe – and the scariest thing is that it’s extremely good at convincing us that these errors are important and correct because it evolved to be really good at grabbing and holding our attention.
The neocortex, on the other hand, has to work very hard in the face of these primitive systems that hijack our attention – and in many instances the limbic system simply takes over.
In other words, we have a constant war between redundant (limbic system) and current (neocortex) systems. The most important thing to take away from this is that because we’re programmed to pay attention to the limbic system (for survival), emotions and desires feel much more important than they actually are – so we give them credence and assume they’re accurate and meaningful (and deserve action). This is why we do so many stupid (and often nasty) things as humans; not because we’re inherently bad or violent, but because we all have a stupid monkey hardwired into our brains that has access to a control button – when it gets activated it can take over and (here’s the worst part), we think that it’s OK because it feels right.
This inner monkey results in two main problems for us humans. First, we spend a lot of our lives as monkeys rather than humans, resulting in a lot of really screwed up crap (think violence, oppression, greed, war, cruelty, etc.). Second, the fact that we have an enormously powerful computer in our heads in the form of our neocortex, that is often unable to act according to its motives, leaves us feeling frustrated and empty. Let me restate, the neocortex isn’t interested in monkey things, it’s interested in novelty, problem solving, language, challenge, meaning, compassion, etc. When we spend our lives indulging monkey behaviour, the neocortex doesn’t get to do what it’s supposed to – and we end up feeling that there’s a deep hole in our lives, that something’s missing, that there’s an emptiness or void in our world, or that life is lacking in meaning.
In part II of this blog, I’ll talk about how to work with the limbic system and build a firewall between the human and the monkey, in order to help us control the redundant systems, and make room for the important human stuff, so that we can experience the sense of meaning and purpose that we crave.
Brilliant summation…looking forward to Part 2!
Nice