I am in the garden – weeding, shovelling, and enjoying the audiobook of The Fellowship of the Ring (BBC version), touchstone of proud nerds. I am in our garden, but as I listen to the words, I am also in Middle Earth (in the tunnels of Moria). My brain slips seamlessly between two parallel realities, neither requiring focused mental work. My mind is projected into sifting weeds and clumps of dirt, and also into the chilling claustrophobia of tunnels in the dark, following a wizard who seems to know where he is going....
The same phenomenon works for us on multiple levels every day. Driving a car, for example– driving along, we experience the feel of tyres on the road, the melody of a song on the radio, the position of the car relative to the road and the external world, and a subtle prediction of what will happen if we follow our current path. We are projected into this environment: our brain immerses us into the external world, and this experience is orchestrated to a rhythm of time in a shifting place, a seamless existence created by the most marvellous biological machinery, which – when working well– doesn’t feel like anything at all.
Who we are – physically – is a brain in a bone box, but the golden trick of the brain is to continuously process bountiful sensory and cognitive information to project us into an external environment. Our mental state is the projection into these spaces, whether they are ‘real’ (my garden) or imagined (Middle Earth). When the neurobiology of this projection breaks down, perhaps as a consequence of mental illness, brain injury, or the gradual degeneration of brain disease, our ability to provide an accurate projection into the external world can be impacted, impeding our interactions with other people and our surroundings. But when it works well, our ability to project gives us the capacity to live within other worlds, such as a book or movie, or even through alternative identities online. Our marvellous brains allow us to colonise both physical and imagined spaces. To thrive, we must nurture and preserve this extraordinary capacity. Protecting our brains from the impacts of technology and neurodegeneration will be key to a healthy future.
Most people likely don’t think at all about their brain. Some may even screw up their face with a disgusted look when reminded that, in some sense, everything they think and perceive originates in the blob-like mass between their ears. If you are reading this book, there is a good chance you are among the minority who does think about their brain.
The majority may spend a large proportion of their day thinking about how they look, what their hands are doing, whether their stomach is rumbling, if their back is sore, whether their arthritis is playing up, or if their eyes feel tired – along with a vast array of other feelings and sensations arising from the body. But the knowledge that these functions are performed by an organ of the body is not front and centre of daily awareness. We’re continually reminded of the essential roles of our heart, lungs and gut, for example, but unless we have a headache, we may not even consider pink blob inside our cranium. Why is that?
We may from time to time consider our internal monologue – the constant chatter, often repeating, returning to particular themes in a circular fashion – but do we attempt to access or focus on the stuff that generates such internal thought? Not so much.
Your brain needs a lot of blood, consumes a lot of energy, and generates electricity – but can you feel it doing those things? Just a quick little exercise: put down this book, close your eyes and see if you can pick up any sensation or feeling of your brain actually working. Give that a minute or two. I’ll leave the rest of the page blank so you are not distracted…
Welcome back. What you probably got by way of internal sensation was more of the internal monologue, perhaps some flitting through images or memories, but nothing directly linked to the electrical and chemical activity of billions of nerve cells, their multiple billions of connections, or their respective trillions of synaptic connections. You experience their function, most often seamlessly, but unlike the beating of your heart or the sensation of your lungs inflating and deflating, you can’t feel them working.
There must be a reason for this lack of direct experience of the brain – driven by aeons of the genetic changes that underlie evolution. The human brain, in particular the outer layer known as the cerebral cortex, sits at the pinnacle of biological evolution. It must work the way it does due to the selection pressures that shaped its functions and operations – resulting in the marvellous organ that provides us with understanding of the world around us, the capacity to communicate with other humans and to have internal thoughts and feelings which only the individual has access to. The brain provides the substrate for our culture, for our capacity to create, interact with and dominate our environment. Overseeing this exquisite capacity, we have consciousness – the personal experience of the world and our internal mental states. We experience the conscious state but it is a slippery, water-between-the-fingers phenomenon that – when working well – is hard to define and describe, both in terms of what it is and what it feels like when it is working.