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Neuroscience

On Consciousness

Where does our consciousness come from? How far does it extend?

In the words of Merriam-Webster, consciousness is, “being aware especially of something within oneself...or...being conscious of an external object, state, or fact.” People are conscious, to be sure. Most people and many animals are observably so, as they express hunger, excitement, fear, joy, or displeasure.

What about smaller creatures or single cell organisms? Experiments have shown that amoeba can sense food sources as distant as one thousand amoeba-lengths and move toward them. At the same time, amoeba move away from dangerous electrical fields. Moving toward things we like and away from things that might harm us is a familiar human behavior, and one we associate with consciousness.

Within us, skin cells sense wounded areas and move toward them while dividing to fill the wound.[i] Neurons sense a need to connect to other specific neurons and grow tendrils for that purpose. Many would interpret that those actions evidence of consciousness, too. Are those components of the consciousness that is us, or do they stand on their own?

Some have suggested that a brain is necessary for conscious and purposeful behavior, but today we recognize many living things that do not have brains yet still act purposefully.

I have often mused about our place in the world. I’ve observed ants and their behavior as part of a larger colony. Are we humans the same? I wonder if we would know. As an example, I used to suggest that our blood cells live and die inside of us, with no possible way to know the totality of what we are. Yet they fight for us and maintain us by transporting oxygen. We created them and absorb them when they die. Now I wonder—Does the fact that they serve us mean they are aware, at some level, of what we are and what they are part of?

We recognize consciousness at the level of a whole being, where we engage in basic behaviors such as food-seeking, and also speculative, contemplative, or abstract thought. We wonder how far such consciousness extends in other animals. It’s clear that many animals anticipate future events, and remember events past. Animals express feelings with respect to both that suggest a significant level of advanced consciousness. It’s quite possible that the main limitation to perceiving nonhuman consciousness is the challenge of human-creature conversation.

We are made up of billions of individual cells. As a whole, our consciousness is vast. We can observe “lesser” consciousness in our component parts. For example, our digestive system is largely self-governing. With the exception of adding food or removing waste, we have no conscious control over it, yet it runs throughout our lives. The conclusion we must draw is that our digestive system is conscious of newly added food, and processes it on demand. Skeptics would say that’s not consciousness; the digestive system is merely a biological machine doing the job it was assembled to do. However, that argument could be applied to any function when comparing it to some ostensibly higher process. If our human totality is undeniably conscious, why would that particular part of us lack consciousness? It certainly acts in our greater interest, which suggests purpose and intent.

At the cellular level, white blood cells recognize threatening bacteria and ingest them. In doing so they expose themselves to risk and death in service to the larger organism of which they are a part. That could imply consciousness at a high level, but many people would deny that, saying again that they are only doing the job for which they were programmed. That produces an interesting dichotomy.

A complete human has the thought that her white blood cells are attacking and neutralizing threats against her at this very moment. She is glad her immune system works, and willingly gives up the white blood cells, knowing she can make more. She realizes their lives are not her life, and she will live on even as they die.

Down in the bloodstream, the individual white blood cells don’t have that luxury. They will fight, die, and be absorbed by the body that created them. Thanks to our higher consciousness, humans often hesitate in the face of danger. We may fight or run. From all we know, our white blood cells do not hesitate. They attack and fight pathogens to the death with no hesitation. Is that courage, or programming?

If you believe the white blood cells are programmed, as opposed to conscious, where does the transition from consciousness to programming happen? If consciousness exists at the level of the whole organism but not the cell, is the transition somewhere between, like an organ?

For a different perspective consider the brain. We believe it to be the seat of consciousness, and we imagine our ideas and feelings take shape among the 86 billion neurons that make it up. Every time we learn something new, the brain performs a subtle act of rewiring. Threads grow from one neuron to another and the web that emerges is the physical embodiment of that skill in us. Processes of learning affect thousands or millions of individual neurons, many of which have hundreds or thousands of existing interconnections. The complexity of connections in our brain is truly unimaginable.

When any individual neuron in that network reaches out to another, in this process of learning, what does it “know?” Is the neuron aware of a cognitive desire that drives the whole brain? Or is it “just following orders?” If any single neuron “just follows orders,” where do the orders originate? You can see the problem here. If we assume our higher consciousness is built from trillions of individually unconscious bits that come together, what is the means of assembly?

We humans consider ourselves to be continuous beings from birth to death. When we remember ourselves as children, we are recalling the being we are today, at an earlier time and an earlier stage of development. Yet we are not the same. Most of the 70 trillion cells in our bodies have comparatively short lifetimes, from a few days to a few years. From childhood to adulthood more than 99 percent of them have been replaced multiple times. The only cells with continuity are in our nervous system—including the brain.

If we believe that the nervous system holds our consciousness, it’s worth noting that what it is most conscious of is its own surrounding body. That makes sense because a nervous system can’t live and function separately from its body. Given that interdependence, and the evidence of conscious action and purpose in other parts of the body (like those white blood cells) it’s hard to justify a limitation of consciousness to less than 1 percent of our body.

We can also look in another direction. 60 percent of our body mass is water. We’ve considered the division of consciousness between our totality, our organs, and cells. What about between our component chemicals? Wherever in our body the consciousness lies, the mass is 60 percent water. So is some of the consciousness in water? If so, is the water outside us also possessed of some consciousness?

If the consciousness is within us, it must reside in those constituent chemicals. If it’s not in the water, where is it? In the potassium, the nitrogen, or the calcium? All seem equally improbable, yet they are what we are made of, and consciousness is a fact. We accept that many assemblages of parts make a sum that’s greater than the whole. Is this such a case, and consciousness somehow springs from the construction?

At this moment I’m not ready to ascribe consciousness to a pool of water, but I’m aware that science is broadening our awareness of conscious and purposeful behavior every day. For example, we now recognize that plants respond to light and dark. Some have distinct behaviors under red or blue light. At some level, they are “seeing.” Plants react to insects chewing their leaves by making themselves less tasty. What can we call that, but feeling the insects and reacting? Evidence has even shown that plants communicate. When one plant in a forest activates its defenses, its neighbors follow suit. To me, that is both conscious and purposeful.

Ten years ago I would not have ascribed consciousness to a plant. In the next decade, perhaps my feelings about water will change too.

References

[i] Le, Cox, Flyvbjerg; Dictyostelium motility as persistent random motion Physical Biology Aug 2012​

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