Homunculus Hash
September 12, 2021
by William P. Meyers

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I am the homunculus.

Ancient philosophers and theologians pondered the problem of how the human mind is connected to the external world long before the word homunculus was coined by Paracelsus in the 16th century. The idea that consciousness continued after death, in the form of a soul, was borrowed by early Christians and others from Egyptian mythology. While Buddhism, at its most sophisticated, concluded that reality is an illusion, other philosophers in that tradition recognized that trying to understand how something that is sensed is made conscious in humans leads to infinite regression, where the same problem just gets recreated at a new level. That eyes project to some sort of screen in the brain, to be watched by a conscious something, which simply led to the same problem at the new level, came to be referred to as the homunculus problem. Thus a little man, or homunculus, sitting watching would have to have its own eyes and brain and so forth. This is a metaphor, not meant to be taking literally.

Chop the Brain into Neurons.

Walking over from the Philosophy Department to the Neurology Department, we learn that the brain, aside from supporting tissues like glia and blood vessels, consists of neurons. Neurons conduct an electro-chemical impulse that can be transmitted to other neurons or to muscle cells. Sensory neurons in the eyes, skin, ears, etc. send signals to the brain, which processes them and makes decisions about what muscles to contract or relax. The process is extremely complicated, with trillion of neurons, most of which connect, via dendrites and axons, to multiple other neurons. The neurons connect at synapses between the axons (outgoing impulse) and dendrites (incoming impulses). There is also hormonal modulation of sets of neurons.

What the homunculus sees and feels is electrical pulses.

If I believe the prior paragraph, there is only one conclusion. I am not directly seeing my computer monitor, I am not feeling the keyboard, I am not hearing the household sounds. All of the world of my consciousness is constructed of electrical pulses. Which solves nothing, it just makes me a homunculus. How can electrical pulses create awareness of a three dimension, multi-color, multi-tonal world? What I think is my body is a representation of my body made by neural pulses. I believe it is a largely accurate representation of the world. Just as the books I read are made of text, ink printed on paper, and I can learn about the world including the past through them, somehow I can be conscious of the objects of the world via the electrical pulses, trillions of them at any one time, that are the business of my neurons. One could say the neurons are the homunculus. They are not a little man, but they serve the homuncular function of creating consciousness. This particular homunculus, the neural model, does not have arms or eyes or an rear end, but it does have its own complexities and mysteries.

Pass through Consciousness

Philosophers and scientists often chop up consciousness into varying kinds or aspects, in hopes that will help in analysis and understanding. It is interesting to look at the mechanism, neurons and brain, without assuming an internal awareness. In broad outline it is easy to do. We call someone conscious when they are awake, unconscious when asleep. When conscious the eyes and other senses give input from the external world, then the brain compares all that to prior learning, or memory, and makes decisions (calculations by neurons on whether to fire) about how the muscles, and hence the human as a whole, will act. This can include talking to others. This model, in broad outline, works very nicely. Neuroscientists can even trace some of the activity of the brain and nerves that allows for human activity, though the details are still largely a mystery.

Staged pseudo-homunculi.

Having dissected brains, we know there are no little homunculi to be found anywhere. But consider a staged homunculi-like, or pseudo-homunculi, progression. Perhaps some regions of the brain are effectively a dog-like awareness, watching what is going on in the pass-through model just discussed. To explain the dog-like model, we have a lizard-brain model. And, perhaps, the final model, a fish like awareness. Thinking about this in detail can be quite informative, and in fact, through evolution, the lizard brain is built on a fish brain, and the mammal brain on the lizard brain, and the human brain on earlier mammal brains. Still leaves us with the question we began with: how is the fish brain self-aware?

The homunculus is complicated.

My guess is that at some point someone, perhaps a neurologist, or a philosopher reading a journal of neurology, will look at some structure and say "by golly, that neural structure could explain consciousness!" it will probably be a relatively large structure, in numbers of neurons, but perhaps not that large as a percentage of brain tissue. With civilization looking like it is highly likely to come to an end soon, the project might not reach completion. Perhaps it will have to wait for a Homo more-sapiens, or some other intelligent species, to get the final answer.