W. Alex Escobar wrote an article for The Conversation that tells you everything you need to know in the title: "Breaking down experiences into millions of parts may help explain consciousness." The rest is details about neurons and qualia (our perceptions of the looks, feels, tastes, etc., of nature around us). The important thing is that his model is a bottom-up approach.
This idea of bits of visual awareness is a bottom-up approach to explain consciousness. It is based on the general architecture of the brain, which is composed of small neural circuits communicating with each other. Already there appears to be evidence supporting the idea of quantised visual awareness (QVA), and this QVA hypothesis sits nicely within much of what is known about the visual system and how it works. (Emphasis added.)
A couple of years ago, we shared a short video of philosopher of mind David Chalmers explaining what the "hard problem of consciousness" is, and why neuroscience would be unlikely to ever solve it, even with a hundred or a thousand more years of scientific progress. More recently, Denyse O’Leary has been writing here about naturalism and neuroscience and the various fallacies naturalists commit in trying to equate the brain with the mind. Has Escobar overcome these?
Escobar tries out his theory on vision, assuming the ideas can be extended to other types of qualia. He sees groups of neurons at a first stage he calls V1, V2, V3 that perceive red, green, and blue, for instance. Then higher-level groupings of neurons (V4, V5, etc.) moderate these inputs, yielding the infinite variety of colors we experience. Result: qualia, from simple building blocks.
Given the constantly changing, highly diverse environments we encounter, it seems likely that the same evolutionary pressures that have produced the complex structures of our bodies would also select for a visual system that could represent a vast number of possible environments from a limited set of qualia building blocks.
Next, he tries to take his idea further to the bottom, so he can evolve it back up:
QVA will allow us to understand the evolution of visual awareness in animals. We no longer need large mammalian brains to create awareness, but only neural circuits of hundreds to thousands of neurons. Imagine a single quale forming long ago within the nervous system of some simple organism. If this provided a selective advantage, over time the number and type of qualia would increase and eventually lead to complex forms of visual consciousness like that found in humans.
He realizes that these circuits needed to be identified, and the hypothesis needs to be tested. But to Escobar, this is the beginning of a naturalistic evolutionary theory for consciousness: it’s just like the evolution of any other complex body part.
Aside from sharing the same problems with evolutionary theories of other complex systems, Escobar’s bottom-up theory of consciousness suffers setbacks peculiar to consciousness. For one, it assumes what it needs to prove: that consciousness supervenes on matter. You can watch neurons firing between themselves for ages, and never see the conscious experience of qualia.
Another setback is that his system provides no confidence that one person’s qualia are similar to another person’s. He might point to natural selection and common ancestry to support this, but then one would expect humans from one side of the planet to develop completely different qualia from those on the other. When Europeans met Native Americans who had crossed the Bering Strait long ages before, they were able to relate to one another as if their perceptions of nature were very similar, language differences notwithstanding.
A third difficulty is that Escobar doesn’t solve the "zombie" problem discussed by Chalmers. Evolutionary theory might account for sensory organs that can react to red or green, or loud or soft sounds, without ever leading to consciousness, thus resulting in "zombies." Conscious experience is above and beyond what is necessary for survival. Each of us knows that we are not merely reacting to stimuli; we are experiencing the world in a deep, personal way. Consciousness is superfluous to evolutionary theory.
We’re being as charitable to Escobar as possible so far, because all the problems with Darwinian evolution as a creative process apply with a vengeance to consciousness. His theory is merely a restatement of Darwinism as applied to the mind. The mutation/selection process cannot account for irreducibly complex systems that are characterized by complex, specified information.
Darwinian evolutionists have a passion for bottom-up theories. They also have fertile imaginations. It drives them to try to explain the universe, the stars, the planets, the first life, the first multicellular life, and consciousness from simple "building blocks." The realities of life and consciousness are, as Ann Gauger has said of birds in the documentary Flight, "more than the sum of their parts. They’re integrated wholes. They’re alive and responsive," posing severe challenges to Darwinian evolution.
Come to think of it, you could ask Escobar to explain truth and morality with his theory. You might then ask, with C.S. Lewis, how he could know it was true, including the concept that things can be explained from the bottom up.