LOOK! NO GOD!
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LOOK! NO GOD! |
ConsciousnessThis article looks at consciousness.
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What is Consciousness? I perceive a world, whether objective or subjective (see Existence). What's more, I am aware of the world. I am also aware of myself as a part of that world and of my thoughts. These things make up my consciousness. Defining consciousness any more rigorously than that isn't possible, though it is often described as thoughts, experience, knowing, feeling, or 'what it’s like to be something'. What's it like to be a dog? Probably quite different from what it's like to be a pineapple. If it is indeed different, that difference lies in the relative consciousness of the two beings.
In a sense, though, not being able to rigorously define consciousness shouldn’t be too much of a problem because we all (presumably) know what it is - we experience it. It's not like we're trying to explain what it is to someone who hasn't experienced it. How does Consciousness Arise? Even though consciousness is something we are all familiar with, understanding how it comes about is a different matter. There are theories about the mechanisms behind it, though none can go as far as actually explaining it, and so all are tentative. Materialist Theories Materialist theories attempt to explain the world in terms only of the entities which are subject to laws of physics - space-time, fields, particles, forces, quantum effects etc. The main materialist theories of consciousness are as follows. Neuron Firings The mechanism favoured by most scientists and psychologists is that consciousness arises as an emergent phenomenon from the pattern of electrical firings of neurons in the brain. How this gives rise to consciousness is not understood.
Evidence in favour of this explanation comes mainly from the fact that changes to the firing patterns are associated with changes to the state of consciousness. General anaesthesia modulates the chemical action of neurotransmitters in the neuron synapses, thus suppressing electrical activity, in particular communication between different parts of the brain. This results in a loss of consciousness. Recreational drugs also affect neurotransmitters and hence firing patterns, leading to altered states of consciousness, though generally without removing it altogether. Endogenic chemicals like adrenalin can affect the electrical activity as can the physical and chemical changes that come with Alzheimer's and other conditions. Quantum Effects A less-widely-held theory is that consciousness depends upon quantum effects related to molecules inside microtubules in neurons, including superposition, wave function collapse and entanglement. This theory aims to circumvent the seeming difficulty of deriving consciousness from purely classical mechanical processes. However, there is little evidence to support the theory, and one difficulty is that many of the proposed quantum effects are only observed at temperatures close to absolute zero, obviously not a condition met in the brain. Panpsychism An even less widely accepted theory is that consciousness is a fundamental property of the universe, extending to all entities, including atoms and subatomic particles. More complex structure have more complex consciousness. Compatibility with Materialism These three models are physical models compatible with a materialist view of the universe. Panpsychism is not compatible with current physics, though that doesn't mean that future physics won't extend to incorporate consciousness of particles. It might also be said that phenomena like extrasensory perception aren't incompatible with a materialist view of the universe. At the turn of the 20th Century, we had no idea of quantum physics or that particles could be in multiple states at the same time. Even now, quantum entanglement seems, at first glance, to defy relativity and certainly defies intuitive classical mechanics. Two particles, even lights years apart can be expressions of a single wave function, making them dependent on one another. Minds could, though process as yet unknown to physics, be connected in a similar way to other minds, to other current happenings or even to happenings in the future. The fact that, most of the time, we do not see this does not mean that is cannot happen. The page on The Paranormal looks further into these ideas in the section 'Extrasensory Perception'. Dualist Theories Dualist theories are ones which assume the existence of a part of us which is not part of the physical universe or our physical brain and which is therefore not dependent upon the physical brain. Probably the majority of humanity are dualists. The non-physical part of us is often called a soul and we will use that term here. Dualism allows various theories of consciousness. We will look at two here. Consciousness is Independent of the Brain In this view, consciousness is purely a property of the soul. The conscious soul acts on the brain to get it to do what the soul wants. The advantage of this view is that it lends itself very easily to the idea of a life after death, again something which most of humanity believe in. The main disadvantage is that it fails to explain how consciousness can be altered or eliminated by physical or chemical changes to the brain like injury, amyloid plaque in Alzheimers, general anaesthesia or psycho-active drugs. It is difficult to see how this view of consciousness can be reconciled with these observations. Consciousness Arises through Interaction of the Soul and the Brain The consciousness of the soul is modulated and limited through interaction with the brain. It could be that, without this modulation, the consciousness is much broader than what we normally experience. In some situations where the brain ceases to function normally, one might experience this less restricted consciousness. Examples might be near-death experiences and maybe the use of psychedelic drugs. This restriction and modulation could be an adaptation to allow us to function effectively in the physical world. This model would allow for continued conscious existence after death. Many people who have had near-death experiences become convinced that death is not the end of consciousness. However, the experiences that lead to this belief could well result from abnormal activity of the dying brain. This is discussed more fully on the page The Paranormal in the section 'Near-death Experiences'. Evidence presented in that section, however, shows that near-death experiences are not obviously compatible with the assertions of any mainstream religion or the idea that religious people have a good afterlife and atheists have a bad one. All in all, it seems that consciousness results purely from the material universe, or maybe that a soul is involved. However, neither model is compatible with traditional ideas of heaven and hell. Degrees of Consciousness Consciousness does always seems to involve memories, perhaps along with current sensory input. It seems reasonable to assume that it relies on these and results from them. It is hard to imagine someone with no memory and no sensory input having anything to be conscious of. They wouldn’t even be aware of the lack of memory or sensory input, because, having no memory, they wouldn’t know that such things could exist. A human embryo with the beginnings of a brain would be unlikely to have much of a consciousness. It seems likely that a rudimentary and very limited consciousness develops in the womb (from sounds and maybe feelings), and that a much fuller consciousness develops once the baby is born and experiences a greater variety of sensory input. If an embryo had the consciousness of an adult, it would get very bored with 9 months floating upside down, doing nothing but giving its mother the occasional kick. Also, if consciousness were an all-or nothing phenomenon, then it would have to have started at an instant in time. It would be hard to see how this would happen in the context of the gradual development of the embryo and its nervous system. So it would seem that there can be degrees of consciousness ranging on Earth from nothing to that of the most conscious human. In general, humans have a well-developed consciousness. Dogs appear to be conscious too, though maybe less so than humans. Spiders may have a rudimentary consciousness. But bacteria probably don’t. If consciousness results from brain activity, having a brain would probably be a pre-requisite. The same would go for trees and rocks. It is conceivable that extra-terrestrials millions of years ahead of us in their evolution might have a degree of consciousness that we couldn’t imagine. Or in fact that humans might get to that state if we survive a few more million years. Consciousness is Unobservable from the Outside One thing about consciousness is that it cannot be seen by an outsider: only the person experiencing it knows it’s there. I know I’m conscious, but cannot tell if anyone else is. Because they seem to be very much like me – they converse with me the way I converse and seem to know and think similar things to what I know and think, I tend to assume that they are. But then a computer programmed with artificial intelligence can hold a conversation with me to the extent, that, if I am talking to it online, I cannot tell that it isn't human. So, either that is not a sufficient criterion for consciousness, or I have to assume that the computer is conscious. That sounds unlikely, but then I have no way of knowing. In a sense, our brains are complex computers which manifest a high degree of consciousness. Maybe simple computers have a very basic consciousness. Split Brains The corpus callosum is a bundle of around 200 million nerve fibres which connect the two hemispheres of the cerebral cortex.
It was discovered in the 1960s that cutting the corpus callosum could cure otherwise intractible cases of serious and debilitating epilepsy. The idea was that the separation of the two halves would stop the chain reactions of nerve firings crossing back and forth between the two hemispheres. Not only did the procedure produce the desired result, but the patients seemed to be fairly normal afterwards. However, researchers experimenting with split-brain patients found some interesting things. The left side of the brain receives visual information from the right half of the field of view and vice versa. It also receives sensory information from the right half of the body and controls the movement of the right half of the body. The left half of the brain produces and understands speech; the right half seems to be able to understand to some extent, but cannot generate speech at all. The researchers flashed images to the right side of the patient’s field of view and asked what it was. The patient answered correctly. But, when an image was flashed to the left half of the field of view, the patient said they didn’t see anything. However, when showed a group of objects, one of which was what had been flashed, the patient could pick out the correct object with their left hand. When asked why they had picked that object, the patient made up some story to justify it. What seemed to be happening was that the left half of the patient’s brain had a mind that was unaware of what was going on in the right half of the brain. It could get clues by seeing what the left hand was doing, but would only see the actions, not be aware of the thoughts. So it had to make up reasons why the left hand did certain things. It was possible to hold a conversation with the left-half mind because it could speak, but the right half, while it seemed to have some understanding of what was said to it, could only communicate through body movements. In most cases, the right brain seemed to be meekly cooperative with what the left brain was trying to do, though not always. On one occasion a patient was buttoning up his shirt with his right hand while his left hand was unbuttoning it again. The left-half mind said it didn’t really feel any different after the operation and seemed to be just as conscious as before. The right half seemed to have a will of its own and, though it couldn’t speak, it seems that it might well have its own consciousness. This suggests that split brain patients could have two independent minds. The question arises ‘Do normal people have two minds or does the constant sharing of data between the two minds make them effectively one mind?’ One is left to wonder whether the mind is really the well-defined, discrete, unified entity that we tend to think it is. Finally, if there was a heaven and a hell, it would be conceivable that, in the case of a split-brain patient, the right half could be bound for heaven while the left half is bound for hell. This is another consideration that makes the idea of judgment and an afterlife problematic. |
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Image Acknowledgements
Dog: Pexels |
