“In the modern age we can chuckle over medieval naiveté, but we often suffer from similar conceptual confusions. We have our share of phlegm theories, which flatter our intuitions while explaining nothing. They’re compelling, they often convince, but at a deeper level they’re empty.”
“One corner of science where phlegm theories proliferate is the cognitive neuroscience of consciousness. The brain is a machine that processes information, yet somehow we also have a conscious experience of at least some of that information. How is that possible? What is subjective experience? It’s one of the most important questions in science, possibly the most important, the deepest way of asking: What are we? Yet many of the current proposals, even some that are deep and subtle, are phlegm theories.”
“Most people have a set of intuitions about consciousness. The physical brain somehow plays host to consciousness, but we suspect that consciousness itself isn’t a physical substance. It’s more ethereal, like a kind of energy. In a similar way, a tuning fork is a physical thing, and its vibrations are the energy associated with it. The vibrations aren’t themselves a physical substance. If you don’t think too hard about it, the vibrations relate to the tuning fork like consciousness relates to the brain. That analogy is even built into our language. We talk about our minds being tuned to this or that vibe. The idea that consciousness is an oscillation in the brain flatters our intuitions. It feels right.”
“When I talk to other scientists about the study of consciousness, very often the first thing I’m asked to explain is why the topic is worth scientific attention. I argue that it’s not just a topic for philosophers or poets, and it’s not just a matter of opinion or belief. We can actually build rational theories of consciousness, theories that have explanatory power and that can be tested experimentally. And it’s crucial knowledge. Consciousness has a specific, practical impact on brain function. If you want to understand how the brain works, you need to understand that part of the machine. No neuroscientist, and no expert in artificial intelligence, should scoff at consciousness.”
“Here’s how we can construct theories that do a better job of explaining, even if they appeal less to our biases and intuitions. The brain is an information-processing machine. It takes in data, transforms it, and uses it to help guide behavior. When that machine ups and says, “Hey, I have a conscious experience of myself and the things around me,” that assertion is based on data computed in the brain.”
“As scientists we can ask a series of basic questions. How did the machine arrive at that self-description? What’s the specific, adaptive use of that self-description? What networks in the brain compute that type of information? These are all scientifically approachable questions. And we are beginning to see specific, testable theories that can answer them. The theories that show the most promise are sometimes called metacognitive theories. They are theories of how the brain computes information about itself and its own processes.”
“The brain constructs packets of information, virtual models, that describe things in the world. Anything useful to monitor and predict, the brain can construct a model of it. These simulations change continuously as new information comes in, and they’re used to guide ongoing behavior. For example, the visual system constructs rich, detailed models of the objects in the visual world—a desk, a car, another person. But the brain doesn’t just model concrete objects in the external world. It also models its own internal processes. It constructs simulations of its own cognition.”
“And those simulations are never accurate. They contain incomplete, sometimes surreal information. The brain constructs a distorted, cartoon sketch of itself and its world. And this is why we’re so certain that we have a kind of magic feeling inside us.”