by Iain McGilchrist
Text used and audio reproduced with the kind permission of the RSA: www.theRSA.org
The division of the brain is something neuroscientists don’t like to talk about anymore.
It enjoyed a sort of popularity in the ’60s and ’70s after the first split brain operations, and it led to a sort of popularization which has since been proved to be entirely false.
It’s not true that one part of the brain does reason and the other does emotion; both are profoundly involved in both. It’s not true that language resides only in the left hemisphere, it doesn’t, important aspects are in the right. It’s not true that visual imagery is only in the right hemisphere, lots of it is in the left.
And so, in a sort of fit of despair, people have given up talking about it. But the problem won’t really go away because this organ – which is all about making connection – is profoundly divided. It’s there inside all of us. And it’s got more divided over the course of human evolution – the ratio of the corpus callosum to the volume of the hemispheres has got smaller.
And the plot thickens when you realize that one of the main, if not the main function of the corpus callosum is in fact to inhibit the other hemisphere.
So, something very important is going on here about keeping things apart from one another.
What is all that about? What are they doing?
Well, it’s not just we who have these divided brains; birds and animals have them as well.
I think the simplest way to think of it is if you imagine a bird trying to feed on a seed, against a background of grit or pebbles. It’s got to focus very narrowly and clearly on that little seed and to be able to pick it out against that background.
But also, if it’s going to stay alive, it’s got to actually keep a quite different kind of attention open, it’s got to be on the lookout for predators.
And it seems that birds and animals quite reliably use their left hemisphere for this narrow-focused attention to something it already knows is of importance to it, and they keep their right hemisphere vigilant, broadly, for whatever might be.
And they also use their right hemispheres for making connections with the world, so they approach their mates and bond with their mates more using the right hemisphere.
But then you come to the humans. And it’s true that actually in humans too this kind of attention is one of the big differences. The right hemisphere gives sustained, broad, open, vigilant alertness, where the left hemisphere gives narrow, sharply focused attention to detail.
But humans are different. The big thing about humans is their frontal lobes. And the purpose of that part of the brain? To inhibit, to inhibit the rest of the brain, to stop the immediate happening; so standing back in time and space from the immediacy of experience. And that enables us to do what neuroscientists are always telling us we’re very good at, which is outwitting the other party. Being Machiavellian. We can read other people’s minds and intentions and, if we so want to, we can deceive them.
But the bit that always curiously missed out here is that it also enables us to empathize, because there’s a sort of necessary distance from the world. If you’re right up against it you just bite. But if you can stand back, and see that other individual is an individual like me who might have interests and values and feelings like mine, then you can make a bond.
So, the distance from the world that is provided is profoundly creative of all that is human.
Now, to do the Machiavellian stuff, we use our left hemispheres. To manipulate the world, which is very important, we need to be able to use – interact with the world – and use it for our benefit. Food is the starting point. But we also, with our left hemispheres, grasp (using our right-hands) things and make tools.
We also use that part of language to grasp things as we say – it pins them down.
So when we already know something’s important and we want to be precise about it, we use our left hemispheres in that way.
So this is very interesting. And it changes the view of the body. The body becomes an assemblage of parts in the left hemisphere.
The right hemisphere’s always on the lookout for things that might be different from our expectations. It understands individuals not just categories. It actually has a disposition for the living, rather than the mechanical.
Let me make it very clear; for imagination you need both hemispheres. Let me make it clear; for reason you need both hemispheres.
So, if I had to sum it up, I’d say the left hemisphere, dependent on denotative language and abstraction, yields clarity and power to manipulate things that are known, fixed, static, isolated, decontextualized, explicit, general in nature, but ultimately lifeless.
The right hemisphere by contrast yields a world of individual, changing, evolving, interconnected, implicit, incarnate living beings within the context of the lived world, but in the nature of things never fully graspable, never perfectly known and to this world it exists in a certain relationship.
And it’s my suggestion to you that in the history of western culture things started with a wonderful balancing of these hemispheres, but in each case, it drifted further to the left hemisphere’s point of view.
The knowledge is mediated by the left hemisphere is within a closed system. It has the advantage of perfection but the perfection is bought ultimately at the price of emptiness.
We live in a world which is paradoxical. We pursue happiness and it leads to resentment and it leads to unhappiness and it leads, in fact, to an explosion of mental illness.
In our modern world, the so-called first world, we’ve developed something that looks awfully like the left hemisphere’s world. We prioritize the virtual over the real. More information – we have it in spades but we get less and less able to use it, to understand it, to be wise. The technical becomes important. Bureaucracy flourishes.
The picture however is fragmented. There’s a loss of uniqueness. The how has become subsumed in what. And the need for control leads to a paranoia in society that we need to govern and control everything. Our daily lives are more subjected to a network of small complicated rules that cover the surface of life and strangle freedom.
And I also think, rather more importantly, there’s a sort of hall of mirrors effect; the more we get trapped into this, the more we undercut and ironise things that might have led us out of it. We just get reflected back into more of what we know about what we know.
It turned out that Einstein’s thinking somehow presaged this thing about the structure of the brain. He said, “The intuitive mind is a sacred gift and the rationale mind is a faithful servant.”