I'm fascinated by the greatest unsolved mystery of science, perhaps because it's personal, it involves my being,your being, my existence,your existence,our existence, foundation of everything we do or don't do. It's about who & what we are... Each one of us.
The mystery is : What is the relationship between our brain and our conscious experiences, such as our experience of the taste of chocolate or the feeling of shaking hands with a friend or smelling the tresses of our beloved ?
In 1868, Thomas Huxley wrote, "How it is that anything so remarkable as a state of consciousness comes about as the result of irritating nervous tissue is just as unaccountable as the appearance of the genie when Aladdin rubbed his lamp."
Why have we made so little progress? Well, some experts think that we can't solve this problem because we lack the necessary concepts and intelligence. We don't expect monkeys to solve problems in quantum mechanics, and as it happens, we can't expect our species to solve this problem either but is it really like this?
Do we see reality as it is? I open my eyes and I have an experience that I describe as a red tomato a meter away. As a result, I come to believe that in reality, there's a red tomato a meter away. I then close my eyes, and my experience changes to a gray field, but is it still the case that in reality, there's a red tomato a meter away? I think so, but could I be wrong? Could I be misinterpreting the nature of my perceptions?
We have misinterpreted our perceptions before. We used to think the Earth is flat, because it looks that way. Pythagorus discovered that we were wrong. Then we thought that the Earth is the center of the Universe, again because it looks that way. Copernicus and Galileo discovered, again, that we were wrong.
Galileo then wondered if we might be misinterpreting our experiences in other ways. He wrote: "I think that tastes, odors, colors, and so on reside in consciousness. Hence if the living creature were removed, all these qualities would be annihilated."
Now, that's a stunning claim. Could Galileo be right? Could we really be misinterpreting our experiences that badly? What does modern science have to say about this?
Well, neuroscientists tell us that about a third of the brain's cortex is engaged in vision. When you simply open your eyes and look about this room, billions of neurons and trillions of synapses are engaged.
Now, this is a bit surprising, because to the extent that we think about vision at all, we think of it as like a camera. It just takes a picture of objective reality as it is. Now, there is a part of vision that's like a camera: the eye has a lens that focuses an image on the back of the eye where there are 130 million photoreceptors, so the eye is like a 130-megapixel camera. But that doesn't explain the billions of neurons and trillions of synapses that are engaged in vision. What are these neurons up to?
Well, neuroscientists tell us that they are creating, in real time, all the shapes, objects, colors, and motions that we see. It feels like we're just taking a snapshot of this room the way it is, but in fact, we're constructing everything that we see. We don't construct the whole world at once. We construct what we need in the moment.
Now, there are many demonstrations that are quite compelling that we construct what we see.
But neuroscientists go further. They say that we reconstruct reality. So, when I have an experience that I describe as a red tomato, that experience is actually an accurate reconstruction of the properties of a real red tomato that would exist even if I weren't looking.
Now, why would neuroscientists say that we don't just construct, we reconstruct? Well, the standard argument given is usually an evolutionary one. Those of our ancestors who saw more accurately had a competitive advantage compared to those who saw less accurately, and therefore they were more likely to pass on their genes. We are the offspring of those who saw more accurately, and so we can be confident that, in the normal case, our perceptions are accurate. You see this in the standard textbooks. One textbook says, for example, "Evolutionarily speaking, vision is useful precisely because it is so accurate."it gives you a survival advantage.
Is this the right interpretation of evolutionary theory? And also this raises an important technical question: Does natural selection really favor seeing reality as it is? Fortunately, we don't have to wave our hands and guess; evolution is a mathematically precise theory. We can use the equations of evolution to check this out. We can have various organisms in artificial worlds compete and see which survive and which thrive, which sensory systems are more fit.
Some of the organisms see all of the reality, others see just part of the reality, and some see none of the reality, only fitness. Who wins?
Latest research has shown that perception of reality goes extinct. In almost every simulation, organisms that see none of reality but are just tuned to fitness drive to extinction all the organisms that perceive reality as it is. So the bottom line is, evolution does not favor vertical, or accurate perceptions. Those perceptions of reality go extinct.
How can it be that not seeing the world accurately gives us a survival advantage? That is a bit counter intuitive. But remember that all the insects & animals have survived millions of years, using simple tricks and hacks so what the equations of evolution are telling us is that all organisms, including us, are in the same boat. We do not see reality as it is. We're shaped with tricks and hacks that keep us alive.
Similarly, evolution has shaped us with perceptual symbols that are designed to keep us alive. We'd better take them seriously. If you see a snake, don't pick it up. If you see a cliff, don't jump off. They're designed to keep us safe, and we should take them seriously. That does not mean that we should take them literally. That's a logical error.
There's nothing really new here. Physicists have told us for a long time that the metal of that train looks solid but really it's mostly empty space with microscopic particles zipping around.
we all see the train, therefore none of us constructs the train. We all see a train because we each see the train that we construct, and the same is true of all physical objects.
We're inclined to think that perception is like a window on reality as it is. The theory of evolution is telling us that this is an incorrect interpretation of our perceptions. Instead, reality is more like a 3D desktop that's designed to hide the complexity of the real world and guide adaptive behavior. Space as you perceive it is your desktop. Physical objects are just the icons in that desktop.
We used to think that the Earth is flat because it looks that way. Then we thought that the Earth is the unmoving center of reality because it looks that way. We were wrong. We had misinterpreted our perceptions. Now we believe that spacetime and objects are the nature of reality as it is. The theory of evolution is telling us that once again, we're wrong. We're misinterpreting the content of our perceptual experiences. There's something that exists when you don't look, but it's not spacetime and physical objects. It's as hard for us to let go of spacetime and objects as it is for us to consciously stop breathing. Why? Because we're blind to our own blindnesses. But we still have an advantage : our science and technology. By peering through the lens of a telescope we discovered that the Earth is not the unmoving center of reality, and by peering through the lens of the theory of evolution we discovered that spacetime and objects are not the nature of reality. When I have a perceptual experience that I describe as a red tomato, I am interacting with reality, but that reality is not a red tomato and is nothing like a red tomato. Similarly, when I have an experience that I describe as a lion or a steak, I'm interacting with reality, but that reality is not a lion or a steak. And here's the kicker: When I have a perceptual experience that I describe as a brain, or neurons, I am interacting with reality, but that reality is not a brain or neurons and is nothing like a brain or neurons. And that reality, whatever it is, is the real source of cause and effect in the world -- not brains, not neurons. Brains and neurons have no causal powers.They cause none of our perceptual experiences, and none of our behavior. Brains and neurons are a species-specific set of symbols, a hack.
What does this mean for the mystery of consciousness? Well, it opens up new possibilities. For instance, perhaps reality is some vast machine that causes our conscious experiences. Perhaps reality is some vast, interacting network of conscious agents, simple and complex, that cause each other's conscious experiences. Perhaps any other ....
But one thing is for sure that once we let go of our massively intuitive but massively false assumption about the nature of reality, it opens up new ways to think about life's greatest mystery. I bet that reality will end up turning out to be more fascinating and unexpected than we've ever imagined.