Rethinking Consciousness: A Scientific Theory of Subjective Experience

by Michael S.A. Graziano

we automatically build models of minds and project them onto ourselves and other people. Our intuitions about a mysterious conscious presence, our conviction that it is present in me or you or this pet or that object, might depend on those simplified but useful models—sets of information that the brain constructs to understand its world.

The difference between overt attention and covert attention is simply this: overt attention is grasping an object with your sense organs; covert attention is grasping an object with the massive computational machinery of the cortex.

Evolution found an efficient way to use a limited amount of brain power and still intelligently process the world.

the brain knows only what it knows. It is captive to its own information.

My first step in reconstructing your mind is to understand that a mind is a thing that has a focus, that the focus can be broad or narrow, depending on circumstances, and can move around from item to item, and that the focus has predictable consequences.

hemispatial neglect,

We’ve become used to a layer of intellectual, cognitive knowledge that conflicts with the brain’s deeper, inborn models.

I SAW A little boy and girl playing on the beach, digging in the sand. They must have been about 5 years old. The boy said, with great earnestness, “We shouldn’t stay in the sun too long or we’ll grow claws.” The girl was astonished. “Really?” she said, staring at him. The little boy nodded solemnly. “It’s true.” He held up his hands and pantomimed pincher movements. “My mom told me.” This vignette is charming because the boy so obviously misunderstood a common metaphor. His mom must have told him that he’d turn into a lobster—meaning, he’d get a sunburn. His mind went to the claws instead of the boiled-red color.

consciousness is part of the brain’s imperfect understanding of reality.

This proposal is called the higher-order thought theory, and it fits into a general framework that is sometimes called “thinking about thinking,” or metacognition.

“Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration, of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others.”

Attention is a layered set of mechanisms—a data-handling method—whereas consciousness is an inner experience that we claim to have. Attention is something the brain does; consciousness is something the brain says it has.

Clearly, attention is not just a local concentration of consciousness. It is a different property.

Anything concrete or abstract, perceptual or intellectual, can be the object of attention.

I know I’m conscious because I have a direct experience of my own mind. But I’ll never really know if other people are conscious. As much as I want to believe it, as much as I love my children and my wife and my cat, I can never directly experience their consciousness.

Any theory of emotional experience must take into account that distinction between emotional state and conscious experience.

To become conscious of an emotional state requires information from those deeper structures to reach the cortical system, where it is integrated with cognitive information about consciousness. In this hypothesis, emotional consciousness contains two parts: information that defines the emotional state and information that defines consciousness. Just as the brain can compute the compound set of information, “I am conscious of the apple,” so it can compute, “I am conscious of my emotion.”

History becomes theoretical over time.

I like to imagine a group of Cro-Magnon men and women sitting around a campfire at night some 30,000 years ago. One of them tells a story about an alien future. Their world will be leveled, the forests cut, the wilderness covered with artificial stones smothering the ground and stacked into giant square caves that block out the sky. The magnificent animals they hunt and paint on their walls will all be dead—the aurochs, the mammoths, the cave bears. The spiritual lifestyle of the hunter will be gone. Almost nobody will know how to make good spears or arrows or anything else with their own hands. Most people will sit inside, in dim light, pressing little clicking squares on a rectangular plate all day long, their bodies turning soft and slow. The air will be choked with human-made fumes, the outdoors roaring with a stupendous and continuous human-made din. I imagine the rest of the clan pulling faces and condemning this dystopian picture. And yet here we are, and we don’t mind it.

Any vision of the future that looks too different from the present must, by definition, be a dystopia.

In that future, mind is something precious, something to be nurtured, grown, and then saved, something that can be lifted from the original biological platform and migrated, duplicated, branched, maintained indefinitely, and even possibly merged with other minds.