ARGUMENT:
We KNOW that neural activity causes consciousness. This is an established fact.
EPISTEMOLOGY:
I reject conceptions of knowledge as justified true belief, on the basis that I don't think "truth" is accessible to us, despite there being a truth that exists. Hence, I subtract "truth" from the JTB, reducing knowledge to justified belief. I expand notions of justification to include all types of justification, including situational justifications.
JUSTIFICATION:
In order for us to KNOW that neural activity causes consciousness, we must show justification for this belief. We will look at the neuroscientific evidence, the elements of causation, a review of alternative explanations, and finally a logical analysis. If we can show that all angles of analysis point to one conclusion, then we have fully justified our knowledge claim. We will even review why the hard problem of consciousness is irrelevant to all of this.
NEUROSCIENCE:
The following will be a quick review of basic neuroscience.
NEURONAL CONNECTIONS:
We have a very clear understanding of how brains work. Modern AI algorithms were largely inspired by knowledge of brain structure. We know that neurons connect to each other with axons and synapses. We know that sodium ions enter the neuron when a neuron is activated, and create a positive electrical charge down the axon until it stimulates the synapses to release neurotransmitters into the next neuron in the sequence of neuronal connections. These neurotransmitters are absorbed by receptors on dendrites, which then help activate the next neuron to produce another electrical charge. We know that each neuron has an activation threshold, meaning the neuron will not activate (action potential) unless it receives a strong enough stimulation. We know that these connections between neurons can be strengthened or weakened, as synapses/dendrites can grow in number or shrink in number. We know that the chain of electric signal between neurons can be boosted or suppressed as there are mechanisms for one neuron to suppress the next neuron's activity instead of activating it. We know that neurons can create interesting shapes with their connectivity, such that a loop shape creates a signal that operates in a circular way such that it creates a feedback loop of growing signaling. We know of at least 8 varieties of neuron interlinking morphology that create important algorithmic functions, like "if/then", "and", "or", "not", and other types of logical structures. We know that in the eyes, the algorithm of "edge detection" is built by a very specific neuronal connection architecture whereby a single neuron suppresses its neighbors, the emergent effect being everything is suppressed except for the edge (of a cliff or other object); and this edge detection can be visually sensed even in simple optical illusions. We know that because of the action potential threshold, the neuron's activity has a binary state of 1: yes (above threshold), and 0: no (below threshold), showing a very similar information paradigm as computer science. We can see that neuronal connections are very mechanistic and deterministic in nature, where one neuron is a cause for the effects of the next neuron in the connection sequence.
QUANTUM IRRELEVANCE:
We can scan brain activity, dissect brains, and examine brain matter with measurement devices to see their microscopic structure. We have a great grasp of the physics of what is occurring at the level of brain activity. We understand that quantum physics is largely irrelevant for brain function, as quantum effects can only be relevant within a small space-time scope, about the size of an atom in influence. Because brain activity operates on a much larger scale than individual atoms, these small effects are largely irrelevant in scope. Also, sprinkling randomness on the brain is also irrelevant due to the fact that one random event is very likely to be canceled out by another random event posed in the opposite way.
BRAIN DAMAGE:
We can examine patients with brain disorders or brain damage, scan to identify the area of damage, and then measure their loss of function based on area of damage. We can see how brains that are severed in half create two separate personalities within one body, one being atheistic, more detail oriented, and slightly less happy, one being more theistic, more big-picture thinking, and slightly more happy. We can discover interesting features about these half-brain personalities, like their access to vocabulary words being restricted - one half of the brain knowing the word "fire", the other half of the brain knowing the word "truck", but neither half of the brain able to put together both into the word "firetruck". We can see how tumors in brains cause personality changes, even as drastic to the onset of pedophilia. We can see how gradations of damage cause gradations of change in specific functions based on the specific location of the change. We can see that the accrual of stress hormones in different areas of the brain also produces diminished functionality in those areas. By measuring the relationship between cause and effect at every level of intensity, we can build a model of tight correlation between damage and loss of function (both behavioral and sensorial). If the visual cortex is damaged sufficiently, you lose your sense of sight. If your audio cortex is damaged sufficiently, you lose your sense of hearing. We have even located the "light switch" of consciousness in the Reticular Activating System (RAS) of the brain stem, as brain damage to this region "turns the lights off" in consciousness. The pattern is clear - damage the brain, damage conscious experience.
BRAIN ALTERED:
We know that when brains are altered by chemicals, there can be remarkable alterations of conscious experience. Pain can be completely suppressed. Consciousness can be "turned off". Alcohol can disinhibit behavior by weakening the prefrontal cortex. Caffeine can energize the brain by functioning as an additional neurotransmitter to further excite neurons to their thresholds for action. A variety of drugs have a variety of interesting effects on the brain. The pattern is clear - alter the brain, alter the conscious experience.
BRAIN STIMULATED:
We can stab individual neurons with needles, measure their electrical states, and pump them with electricity as desired and test why type of result arises from our artificial stimulation. We can inject DNA into neurons to make them activate or deactivate when we shine a special wave of light upon them, and then see what types of effects derive from wide-scale brain manipulation. We can build disembodied brain blobs and hook them up to electronic equipment to see how they adapt to interfaces. We can observe learning in these brain blobs based on reward conditions in the environment. The pattern is clear - stimulate the brain, stimulate conscious experience.
BRAIN READING:
When we scan brains we can get baseline data for neural activity. When we damage, alter, or stimulate brains, we can see changes in neural activity, and measure their resulting effects in behavior or consciousness. We can measure the degree of change against the degree of intervention, to see how tightly correlated the two are. Brain measuring technology is now so refined that you can point a computer mouse with your mind, by virtue of a neurolink measuring your brain activity. You can also activate robotic arms with your mind. You can also output numbers with your mind. All of this shows a tight correlation between the neural activity and what you are actually thinking.
Cause: Damage neural activity
Effect: Damage behavior or conscious experience.
Cause: Alter neural activity
Effect: Alter behavior or conscious experience.
Cause: Stimulate neural activity
Effect: Stimulate behavior or conscious experience.
Neural pattern = Conscious intentions
CONSCIOUSNESS:
For purposes of this argument, I do not need to provide evidence for all of the claims above. Those are just to provide context and can be researched separately. The only thing I need to provide evidence for is the causation between neural activity and consciousness. Consciousness can be defined in different ways, but for my purposes, consciousness is the sum of all qualia. Qualia are the building blocks of consciousness. The experience of "redness" is vision qualia. The experience of pleasure is valenced qualia. The experience of the idea of a "tiger" is a combination of many types of qualia, both color, shape, function, and intention qualia, which further break down into smaller building blocks of qualia. In essence, qualia can be surmised as units of sensation. If I can show that brain activity causes sensation then my argument is justified.
EVIDENCE:
In 2010, a 100 year summary of neuroscience was published. They produced a map of all the experiments performed thus far, indicating which types of effects were derived by which types of stimulation. The analysis mapped sensory, motor, autonomic, emotional, and cognitive effects to the specific region of the brain being stimulated. For my purposes, I only need to show the sensory effects derived by brain stimulation. As you can see in the chart below, a vast array of sensory experiences were able to be produced by artificial activation of neurons. We can see the sense of sound being produced by brain activity, the sense of vision being produced by brain activity, even the sensation of weight or weightlessness. One's sense of one's position in space-time can be affected. Sense of touch in the skin can be produced. Sense of smell can be produced. Sense of movement can be produced. If all of one's conscious sensations can be artificially produced by artificial brain stimulation, shouldn't it follow that one's conscious sensations can be naturally produced by natural brain stimulation?
CAUSATION:
Central to my argument is the concept of causation - that neuronal activity causes consciousness. How do we prove causation? (C → E)
Sequence test: The cause must occur before the effect.
Consistency test: Whenever the cause occurs, the effect must also occur.
Gradation test: Relative increases in the cause results in relative increases of the effect.
"But-for" test: if X had not occurred, would Y have not occurred?
No Alternatives test: There must not be another factor that can explain the relationship between the cause and effect.
Sequence test:
It is obvious that neural activity passes the sequence test. We inject the electricity into the neurons sequentially prior to the effects. The effects occur immediately after. There are also Libet style experiment that show how there is predictable neuronal patterns of activity before conscious decisions to take actions take place, showing a sequential connection between brain activity causing conscious decisions, which then cause actions.
Consistency test:
The above analysis reviewed 9272 reports on scientific findings over 100 years. The findings of brain science have been replicated over and over with incredible consistency. Whenever we want to create an effect, we can just initiate a cause within the neurons. Neurons operate on non-quantum laws of physics, and non-quantum laws of physics are extremely consistent.
Gradation test:
Neuronal activity produces predictably different results based on the intensity of the stimulation. Neuronal activity produces predictably different results based on the frequency of the stimulation. The effects of neuronal activity can be boosted by some chemicals (caffeine) and suppressed by others (alcohol). Different levels of damage produce predictably different levels of harm to brain function. There is a tight correlation between units of change and units of effect.
"But-for" test:
The "but-for" test is when you test the case wherein your cause never occurred. If the cause never occurred, would the effect still occur? If the effect would not occur but for the existence of the cause, we have passed the "but-for" test. For neural activity, we know that if we don't introduce the stimulus, we don't derive the effect. We know that if we don't induce the suppressive chemicals, we don't suppress the conscious experience. We know that if we don't damage the brain, we don't derive the effect of damaging conscious experience and function. Its very clear that the effect occurs with the cause, and doesn't occur in the absence of a cause.
No Alternatives test:
The “no alternatives” test is the test for ruling out all other possible explanations. When it comes to consciousness, there are a few popular ideas about it. One thing we need to make clear is that what we are discussing is the cause and effect of consciousness, rather than the ontology or nature of consciousness. The most common theory of consciousness is the “emergentism” or the idea that consciousness emerges from brain activity – this is the idea that we are supporting at this time.
Another idea is “panpsychism” or the idea that consciousness is fundamental to all material (even electrons having their own conscious selfhood). Under panpsychism, neural activity would not cause consciousness, because consciousness does not need to be caused, it is natural and automatic to all materials. Panpsychism has a problem with the phenomenon of “turning off” or “suppressing” consciousness. If consciousness is innate to materials, why is it that when we add more materials like sedatives, instead of adding to the richness of consciousness, they put you to sleep and “turn off” conscious experience? It seems like panpsychism fails to explain causality in consciousness.
“Idealism” is the most weird perspective on consciousness – it is essentially the idea that the universe is a dream-world invented by the fundamental ultimate consciousness. It is the idea that consciousness exists first, and then materials are dreamed up by that consciousness. It flips causality backwards – materials don’t cause consciousness, consciousness causes materials. If this were the case, we would find that people could delete or create materials with the power of their consciousness. Of course, this is exactly what they claim. If only you can wish hard enough, manifest hard enough, think enough positive thoughts, you can summon your dreamed-up ideal future into existence. The only problem is that this is completely magical and lacks any scientific evidence. Under this paradigm, there would be no reason for materials to effect consciousness, since that is the opposite conclusion of the paradigm. Yet we know that materials do effect consciousness, so this alternative is patently debunked.
“Dualism” is a more ancient perspective on consciousness, claiming that there are two substances, mind and matter, or body and spirit. These two substances interact, the immaterial commandeering the material. The problem with this theory is that if an immaterial substance is controlling the material substance, we should be able to detect changes in the material being induced. For example, if a ghost was playing the piano, even though we couldn’t see the ghost, we could still see the piano keys being affected. In the case of the brain, the piano keys would be neurons. We should see neurons activating as if by a ghost, rather than activating as if by a domino effect of one neuron to the next in a chain of sequential activity. When we scan the brain, we detect no otherworldly physics puppeteering brains, and hence this explanation fails.
“Transmission theory” would suppose that our brains are more like radios that receive consciousness from external cosmic signals rather than produce it. One formulation of this idea would suppose that brains are sending requests to the external source, and then receiving answers from this external source. We should be able to observe the causal structure of this – we should detect energy leaving the neuron in the form of a request, and energy returning to the neuron in the form of a reply. Yet, there is no evidence of such a process. Another formulation of this idea is that the materials of the brain are just puppeteered by these external signals. The brain, like a radio, receives the signals, and then deterministically follows the commands of these signals. If this were the case, we would detect energy signals being absorbed by neurons in the form of external activation. We could also put people in metallic cells that block energy signals and see if they lose their consciousness, due to their inability to receive signals through the thick metallic walls. Such phenomena don’t exist. Perhaps they would like to say that these external signals are not energetic in nature, but rather spiritual in nature – beyond detection. This then just reverts into a type of dualism and suffers the same problems discussed above -no piano keys have been observed playing themselves.
The number of alternative explanations for consciousness are as endless as the human imagination, but the pattern is clear – all other theories of consciousness are fundamentally flawed, lack evidence, don’t fit the data, invoke magic, and lack parsimony. We are justified in the emergent perspective of consciousness whereby neural activity causes consciousness.
After reviewing the above criteria for proving causation, I think we can in good conscience say that the argument that neural activity causes consciousness has passed with flying colors.
HARD PROBLEM OF CONSCIOUSNESS:
It is often that people are confused about the hard problem of consciousness. Simply put, the hard problem of consciousness is the how and why of qualia. It is the question of how and why physical facts translate to qualitative facts in consciousness. It is the question of how the movement of particles transforms into a different nature, such as color, pleasure, pain, music, taste, etc.
One thing you should notice is that this problem is a more microscopic problem than the problem of causation. Causation is a macro-level problem. We activate the neuron; we get a conscious experience. We create the cause and observe the effect. Nothing about the problem of causation requires us to know exactly what the neurons are doing at a microscopic level in order to convert our stimulus into a different form. Just like we can measure cause/effect relationships when training dogs to obey commands without understanding the microscopic changes within them, we can measure cause/effect relationships in neurons without understanding what is going on at a deeper level.
But there is a problem tightly related to the hard problem of consciousness – why do some materials create conscious experience and not others? Why do some physical facts produce qualia and not others? Why do some particle collisions create feelings and not others? A commonly reported statistic is that only 5% of our neural activity is conscious. 95% of neural activity is unconscious. In the 100 year review of brain science referenced above, many effects of brain stimulation produced no conscious experience, but rather created some physical function. This creates a dichotomy wherein some neural activity causes consciousness and other neural activity causes biological function.
LOGIC:
We can represent "specific neural activity" (the type that produces qualia) as 'N'; we can represent "conscious experience" as 'C'. Premise 1: If 'N' then 'C'. We have more than substantiated this premise in our discussions above. With a logical inversion, we can flip premise 1 upsidedown and derive its contrapositve, if no 'C', then no 'N'. The contrapositive shows that our premise necessitates the conclusion that the lack of consciousness means that we are lacking specific neural activity.
Premise 1: N → C
Premise 1 (CP): – C → – N
In our "but-for" test, we further substantiated the idea that "if there is no specific neural activity, then there is no conscious experience". The following contrapositive is very important. By inverting the logic, we see that it also necessarily follows that "if we have a conscious experience, then we must have some specific neural activity". Now this point is largely debatable! Some people think that AI robots should be able to achieve consciousness without neural activity! Or perhaps aliens evolved brains made out of different stuff, and hence don't require neural activity. So for our purposes we must reduce the scope. We are talking about humans. Not aliens. Not robots. For the purposes of humanity, if we don't have specific neural activity, we don't have conscious experience. And hence, human consciousness necessitates the conclusion of specific neural activity.
Premise 2: – N → – C
Premise 2 (CP): C → N
By conjoining the logic above, we can see clearly that there is a bidirectional relationship between specific neural activity and consciousness. We have proven biconditionality between 'N' and 'C'. If we have one, we must have the other.
Premise 1: N → C
Premise 2: C → N
Conclusion: N ↔ C
CONCLUSION:
We have shown the mechanisms for how brains work, how they are very mechanistic and deterministic in nature. We have explained how quantum effects do not apply. We have discussed how chains of cause and effect go from neuron to neuron in sequential form. We have revealed how these causal links can be hacked by neuroscientists and artificial stimulation or suppression can be applied to test the effects on the brain. We have shown how massive amounts of research and experimentation have proven this causal connection over and over again. We have investigated the nature of causation and assessed it from every angle. We have proven sequence, consistency, gradients of causation, and “but-for” causation. We have addressed a variety of alternative explanations and shown how they are wholly insufficient. We have explained how the hard problem of consciousness is irrelevant to the question of causation. Finally, we have portrayed in logical form how our premises produce a biconditional relationship between neural activity and consciousness. From every angle of analysis, the conclusion is crystal clear, neural activity causes consciousness. We are justified in this knowledge claim.
REFERENCES:
"Electrical brain stimulation can be considered a useful tool for functional mapping in the human brain. Contrary to most neuroimaging studies, which do not probe directly the necessity of a given brain region in a particular cognitive function, EBS can provide direct observations about the necessity of the stimulated region for the perceptual or behavioral function that is being studied."
“Microstimulation allows the causal relationships between neuronal activity and sensation to be established.”
“The recent development of single neuron stimulation techniques revealed single cell effects on perception, movement and even brain states”
“Electrical stimulation of the brain also is capable of dissociating voluntary intention from the actual production of movement. Penfield and Boldrey found that surface stimulation of the precentral gyrus occasionally evoked a “desire to move” a particular body part although no movement occurred.
As the stimulation amplitude was increased, the participants experienced “illusory movements,” describing that their mouth, hand, foot, or chest had moved, although no actual movements were detected by observers or by electromyographic (EMG) recordings.
Stimulation in the supplementary motor area likewise has evoked an “urge” to perform a movement, or a sense of anticipation that a movement was about to occur, with no actual movement associated.
In contrast, when the same investigators delivered electrical stimulation to the premotor cortex, actual movements of different body parts were evoked, but here the subjects were unaware the movements had occurred and denied any intent or desire to make such movements. In other words, the participant was not the agent of these evoked movements.”