The Science of the Human Brain

It is the most complex living system in the known universe, built of hundreds of billions of cells, each as complicated as a city.

It is the primary author of the deeply personal story we tell ourselves about who we are and why we are here.

And it never, ever, shows us the world as it truly is — only as we need it to be.

This is the conundrum of the human brain, which is why understanding its peculiar science is a prerequisite towards our ability to imagine, and then build, a better world.

Consider this: Human beings — or, for that matter, any other life form on earth — see only what has helped them survive in the past. The way we make sense of the present is still being shaped by the innovations, fears and assumptions our ancestors made hundreds, thousands, even millions of years ago. And yet our success as a species has occurred not in spite of our inability to see reality, but because of it.

As neuroscientist Beau Lotto puts it, human beings didn’t evolve to see the world objectively; they evolved to “not die.”  And all living things have managed to “not die” thus far by developing different perceptual overlays on the same planetary backdrop.

Bats developed echolocation.

Cephalopods learned to change colors.

Birds got GPS.

And we developed a wet computer with a parallel processor — otherwise known as a bi-hemispheric brain.

Why did our brains evolve that way, with a singular blueprint stamped out twice? No one knows for sure, although psychiatrist Iain McGlichrist believes it happened to help us “attend to the world in two completely different ways, and in so doing to bring two different worlds into being,” and two different ways of surviving life’s slings and arrows.  

“In the one,” he explains, “we experience — the live, complex, embodied, world of individual, always unique beings, forever in flux, a net of interdependencies, forming and reforming wholes, a world in which we are deeply connected. In the other we ‘experience’ our experience in a special way: a ‘re-presented’ version of it, containing now static, separable, bounded, but essentially fragmented entities, grouped into classes, on which predictions can be based.

“These are not different ways of thinking about the world,” McGilchrist claims. “They are different ways of being in the world. If the left hemisphere is the hemisphere of ‘what’, the right hemisphere, with its preoccupation with context, the relational aspects of experience, emotion and the nuances of expression, could be said to be the hemisphere of ‘how.’”

Who we perceive ourselves to be is a mashup of these different perceptual overlays — ostensibly equal parts logic and emotion. And yet the reality of the modern world, says McGilchrist, is that our way of seeing has gotten out of balance.

For a number of reasons, we have become left-hemisphere heavy.

“My thesis is that for us as human beings there are two fundamentally opposed realities, two different modes of existence; that each is of ultimate importance in bringing about the recognizably human world; and that their difference is rooted in the bihemispheric structure of the brain. It follows,” he asserts, “that the hemispheres need to cooperate, but I believe they are in fact involved in a sort of power struggle, and that this explains many aspects of contemporary Western culture.”

Is it possible to bring ourselves back in balance? Harvard neuroscientist Jill Bolte Taylor would say yes — and she would know. In 1996, a blood vessel burst in the left half of her brain. “In the course of four hours,” she explains, “I watched my brain completely deteriorate in its ability to process all information.”

Because Taylor had spent her adult life studying the brain’s intricate architecture, she was uniquely suited to observe how the stroke was affecting her. What she discovered has huge implications for how all of us think about who (& why) we are in the world.

But first, a refresher course:

On one side of our brain, there is the right hemisphere, which is designed to help us remember things as they relate to one another. “To the right mind,” Taylor says, “no time exists other than the present moment, and each moment is vibrant with sensation. By design, our right mind is spontaneous, carefree, and imaginative. It allows our artistic juices to flow free without inhibition or judgment.” And it gives us the sense that we are indistinguishable, infinite, and interconnected.

By contrast, our left hemisphere organizes the world for us in a linear and methodical way. “Here,” says Taylor, “the concept of time is understood as either past, present or future, and our left brain thrives on details. Here, we use words to describe, categorize, define, and communicate about everything we see.” And here, we find the part of ourselves that feels most distinct — the part that proclaims, ‘I am,’ apart from the world.

Because Taylor’s stroke occurred in the left side of her brain, her right hemisphere was left unchecked by its usual counterbalance. As a result, she experienced a drastically different way of seeing the world (and her role in it). “I no longer perceived myself as a single, a solid, an entity with boundaries that separated me from the entities around me. Everything around us, about us, among us, within us, and between us is made up of atoms and molecules vibrating in space. Although the ego center of our language center prefers defining our self as individual and solid, most of us are aware that we are made up of trillions of cells, gallons of water, and ultimately everything about us exists in a constant and dynamic state of activity.

“My left hemisphere had been trained to perceive myself as a solid,” she explained, “separate from others. Now, released from that restrictive circuitry, my right hemisphere relished in its attachment to the eternal flow. I was no longer isolated and alone. My soul was as big as the universe and frolicked with glee in a boundless sea.”

For Taylor, the lesson is not that one hemisphere is better than the other; indeed, there is a reason our brain evolved this way — which is, simply, to integrate two contradictory yet complementary ways of seeing the world: one holistic and boundless, the other segmented and bound.

Rather, the lesson comes when we accept, as Beau Lotto puts it, that “the world out there is really just our three-dimensional screen. Our receptors take the meaningless information they receive; then our brain, through interacting with the world, encodes the historical meaning of that information, and projects our subjective versions of color, shape and distance onto things.

“Meaning is a plastic entity,” he reminds us, “much like the physical nature of the brain, which we shape and reshape through perceptual experiences. It is critical to understand that the meaning of the thing is not the same as the thing itself.”

Believing is seeing, more than seeing is believing. And so we will never change the story of how we learn and live unless we become aware of the way our brains are always trying to ensure that we “not die” — by providing us with a coherent story about our lives, a story that our brain works around the clock to create.

A story that is never, ever, accurate.

To see differently, we must learn to see seeing differently. “The more aware I remain about what my brain is saying and how those thoughts feel inside my body,” Taylor tells us, “the more I own my power in choosing what I want to spend my time thinking about and how I want to feel. If I want to retain my inner peace, I must be willing to consistently and persistently tend the garden of my mind moment by moment, and be willing to make the decision a thousand times a day.”

The clearer we are about the science of the human brain, in other words, the greater the chance we can appreciate the art of individual identity.

It is the most wondrous thing we have discovered in the universe, and it is us.