The "Hard Problem" of Consciousness

Talk presented to the Atheist Society, 13 September 2011, by Graeme Lindenmayer

What is Consciousness?

Many descriptions of it have been proposed, and many also of mind. The two are sometimes thought to be the same thing, but the term unconscious mind suggests that consciousness and mind are not identical and that mind may have wider connotations, involving both consciousness and unconscious intelligence.

Intelligence comprises the processes of detecting and recording data, remembering, reasoning, calculating, and reacting. Although we usually think of intelligence as a property of living organisms, it can also be a property of inanimate objects such as computers, which, presumably, are not conscious.

Consciousness may be thought of as a gradation of conditions that we call awareness. And there are other words as well as consciousness and awareness, like feeling and experiencing and subjectivity, but they all mean much the same.

I think the degrees of consciousness are:

  1. merely being aware;
  2. being aware of something;
  3. being aware of existing as an entity;
  4. being aware of observing, thinking, remembering, imagining, reasoning, deciding, wanting and controlling. (The unconscious mind seems to be able to do these things without feeling or experiencing them.)
There seem to be different kinds of consciousness, not just everyday kind when we are awake. Dreaming is a kind of consciousness at a time when we are asleep and not aware of our surroundings. People in deep meditation claim to reach "higher levels" of consciousness. None of us is immediately aware of everything in our memory, but we recall (ie., bring to consciousness) specific parts of memory, either intentionally or "spontaneously". Certain experiences usually regarded as abnormal (such as hearing voices that other, "normally functioning", people can’t hear) and states caused by "mind-altering" drugs are other aspects of consciousness.

These are illustrations of consciousness, but how can the existence of such a thing be explained? Two opposing ideas receive the most credibility, the materialistic and the dualistic.

The materialistic concept is that consciousness is purely a process of the brain, just as digestion is a process of another organ of the body the alimentary system.

The dualistic concept is that consciousness is the process of a supernatural entity interpreting the workings of the brain. This has been referred to as "the ghost in the machine".

There are other views but they are not widely held.. One is that consciousness is an inherent property of all matter, additional to those properties, such as mass and electric charge, that are described and quantified by science. This implies that even electrons and protons have some rudimentary consciousness, and that as material structures become more complex they can become more complexly conscious. So a very complex structure like the brain could be intrinsically very conscious. I don’t think that this implies that mere size would result in greater consciousness. But it might imply that having some kind of sensory organ would provide a suitably structured lump of material with something to be conscious of.

There is no scientific evidence for this. I don’t know of any way of proving or disproving it and it does not help in explaining the characteristics of the consciousness that we experience. Our computers may sometimes infuriate us, but there is no reason to think they are conscious, despite their intelligence and complexity.

It has been suggested that there are "psychophysical laws" that would show the link between intelligence and consciousness in living organisms. These are not laws of physics, but neither are they supernatural. The closest to a statement of such a law that has been made is that there is always an action in the brain associated with every conscious experience. (Psychophysics is the study of the correlation between kinds of physical stimulus and kinds of subjective reaction.)

A second "minority" view is that consciousness is completely supernatural, ie., independent of any material process. This is implied in the concepts of the eternal soul that continues to exist after the death and disintegration of the material body, and of reincarnation, in which a particular conscious entity inhabits a succession of bodies, entering each after the death of the previous body. None of the claims supporting this have been substantiated.

And there is the claim that consciousness does not exist. But our consciousness is the very essence of our being and we all claim to be conscious (unless those who say we are not claim they are not conscious of denying it). Its characteristics can be described, and argued about with not very much disagreement.

Another way of putting this idea of non-existence is that consciousness is an illusion. The obvious answer to this is to ask who or what is having the illusion. Perhaps it is the brain that has the illusion, but this puts consciousness as just another operation of the brain, which is the materialistic concept.

I think it is safe to dismiss at least the second and third of these minority explanations. Because consciousness is entirely dependent on both the condition of the organism's brain and situation (ie., where the conscious organism is, and whether it is dark or well-lit, quiet or noisy, etc.) it must be unique to each conscious organism. Therefore it must be an interpretation of what is "in" the brain, not something independently conscious. The question is whether the thing that is "actually" conscious is the brain or something else. And then, whether that something else could be material or supernatural. The Materialistic and dualistic explanations will now be discussed in detail to see if we can find justifiable answer to these questions.

Materialistic Consciousness

Scientists have now developed a detailed neurological description of how brains detect, store and process all the inputs they receive from the material world. The electro-chemical processes in the brain that are associated with subjective perceptions and feelings have been fairly well identified. Specific locations in the brain become active during all of our mental processes. The operations in each these areas and the interconnections between different areas have been studied while people are performing various tasks. Specific locations that have been recorded to become active when a person performs a particular task or action also become activated when they think about that task or action.

Various material processes affect consciousness. Anaesthetics are used to artificially deprive us of consciousness and to reduce pain when we are conscious. Emotions and other subjective feelings are known to be associated with the action of neurotransmitters in the brain, and are also affected by drugs such as hallucinogens, narcotics, stimulants and depressives. These substances have a role in promoting or hindering certain interactions within the brain. Electric and magnetic fields applied to specific structures of the brain have been shown to affect the senses and thinking, by temporarily interrupting or promoting electro-chemical processes of neurons. Damage, deterioration and congenital abnormalities of the brain have well-documented subjective affects. There are parts of the brain that are associated with emotions, and different conditions of these parts, such as the concentrations of various neurotransmitters, have been shown to be associated with emotional effects.

Pain and its related feeling of itchiness are associated with sensory nerves that are responding to something wrong or unusual with a part of the body. Pain and itch have the function of alarm signals, prompting action that may prevent or reduce further damage. But the sensations can often be shut off or ignored by the mind (or the brain) when it is completely preoccupied by something else – as can also happen with other types of alarm systems in the physical world.

The inputs from the sensory organs – such as colours, shapes, sounds, etc. – are represented in the brain as networks of widely interconnected neurons. Such networks are continually being connected with previously established networks to build larger networks, which are then added to even larger, interconnected, networks that constitute stores of memories. Other networks of neurons analyse and compare these networks, interpreting the inputs, and, perhaps, thinking about them. And there are other networks that are "pre-wired" to affect the production of neurotransmitters. This can then produce sensations of fear, pleasure, anger, etc., in response to the presence of certain types of connections in other networks. Some of these built-up networks may last for only brief moments but others may remain connected as memory.

The materialist concept envisages consciousness as a "high level" process in which "lower level" processes are continually combined so as to provide a generalised overview. Examples of such lower level processes are memory, interpretation of inputs from outside the body, association of certain memories with other memories or warning signals, and reasoning.

The US philosopher Douglas Hofstadter has developed a case in his books Gödel Escher Bach and I Am A Strange Loop that self awareness is the brain’s presentation to itself of its own processes, ie., by high-level networks repeatedly connecting back to each other. The other aspects of consciousness are similar loops continually presenting to themselves the networks that perform the sensory, memory, reasoning and other functions of the brain.

This would be consistent with the finding that while there appear to be specialised networks for each of the various kinds of brain activity, and, presumably, for each kind of consciousness, there seems to be no overall network representing a unified "self". And psychologists say there is, in fact, no unified consciousness.

I will now digress from organisms to machines. Some kinds of artificial intelligence are able to detect aspects of the environment, store the details in a memory, process the contents of the memory according to rules – which would be partly in-built and partly learned – and respond to aspects of the environment in accordance with other prescribed rules. Some motor vehicles do all of this. They take part in regular competitive trials where they travel autonomously over distances exceeding 100 kilometres on rough terrain in remote areas of the USA.

No one is saying that these vehicles are conscious, but they are undeniably intelligent. Some people expect conscious machines to be eventually produced as an emergent consequence of more sophisticated artificial intelligence.

Dualistic Consciousness

Many philosophers and neuroscientists claim that there is no satisfactory explanation of how physiological processes could produce consciousness. Trying to produce a credible explanation was described as "the hard problem of consciousness" by the by academic philosopher David Chalmers in his book The Conscious Mind, which he describes as being "In search of a fundamental theory".

One argument against the materialist explanation is that any information or intelligence that is stored in a brain or a material device consists purely of symbols, and that symbols are not meanings. Materialists point out that meaning, indeed all of our ideas and all that we know and understand, are expressed in terms of language of some kind, or in pictorial or other representations, which are nothing but symbols. Moreover, this argument is only about explaining the information content of consciousness, not of consciousness itself, so it can be dismissed.

Some people claim to have had psychic experiences, that is, seeing or knowing things that they could not have seen or known through the senses, and say these are cases of supernatural consciousness. Examples are prescience, ie., seeing or knowing future events, and out-of-body experiences, ie., being able to look at ones own body from a position outside it and/or see things not visible from the body’s actual position. None of these claims can be substantiated. And there’s a big prize for anyone who does substantiate any paranormal claim.

A stronger reason for disputing the claim that consciousness is a material process is that many conscious sensations are very different in kind from the physiological processes associated with them.

The classic example of this difference is colour. The human eye is able to detect and distinguish a narrow band of electromagnetic radiation. Our brains are able to interpret the various detected wavelengths of this radiation into what we see as a sequence of colours from red to violet.

There is no apparent reason why what we perceive as red should be derived from a longer wavelength than what we perceive as blue. Blue is widely regarded as a "cool" colour and red as a "hot" colour. But blue light has more energy (ie., it is "hotter") than red, because blue light has a shorter wavelength.

Subjectively, white is the absence of colour, but objectively it is a balanced combination of wavelengths. Unless we are trained otherwise, colours such as brown or pink, which are also produced by mixtures of wavelengths, seem no different in kind from the "pure" colours of the rainbow. Again, our sensations do not match the associated physical processes.

Other senses – hearing, smell, taste, etc. – each deliver subjective experiences that, apart from their intensity, don’t generally correlate with the physical conditions that caused them. (Although we can usually pick higher and lower frequencies in sound, the ancient Greeks referred to the higher frequency sounds as low and the lower frequencies as high, in contrast to present day terminology which correlates pitch to frequency.)

Other conscious feelings that have no apparent similarity to their associated patterns of connections in the brain are:

  1. bodily feelings – tiredness, energy, awareness of the need to urinate;
  2. emotions – anger, elation, depression, excitement, awe, reverence, boredom, sadness, mirth, happiness, love, friendliness, hate, disgust, resentment, anxiety, fear, panic, obsession, delusion;
  3. intellectual attitudes – certainty, doubt, disbelief, suspicion, confidence, diffidence, interest.
On the subject of doubt, a computer has many details in its memory, but it is unable to feel any doubt about the truth of those details, even if some of what is in the memory includes data about the probabilities. But if your brain has a store of details about something, you can feel confident or doubtful about it.

There is a saying "there are no boring subjects, only bored people". But there are no bored computers. Computers might break down from fatigue or faulty components, but until then they will chug along indefinitely, neither interested nor bored, nor happy nor sad, irrespective of the content of their task. And the same applies to the neural systems that provide the processing and control functions of the bodies of all organisms, including bored people. We have neural systems with no associated consciousness.

A further reason for thinking that consciousness is not material is that, while we feel we can directly "know about" material things, we can only infer other peoples’ subjectivities. For example, while we generally agree about the names of particular colours, we have no way of knowing whether our own subjective perception of any particular named colour would be similar or different from any other person’s. Other peoples’ subjectivity does not seem directly accessible to us – and neither does the supernatural.

How Could Consciousness be Dualistic?

If consciousness requires a supernatural element, it should be possible to deduce what both that element and the brain would need to do during the differing types of conscious activities. The supernatural obviously could not sense the world directly because its impression of the world depends entirely on the condition of the brain and sensory organs. So the supernatural would need to sense the brain in some special way. Might it also transmit to the brain? It might for functions such as recalling, imagining, reasoning, deciding and commanding bodily movement.

Recalling is the act of recovering something from memory. The memory resides in the brain, as is demonstrated by its deterioration when the brain is damaged. Since we are aware of ourselves trying to remember something, this action might involve some request from the supernatural to the brain, and further dialogue depending on how easy it is for the relevant stored details to be found. So the supernatural consciousness would need to be able to send some sort of signal that the brain can receive and act upon. Alternatively, the sensation of trying to remember might be just passive awareness that the brain is trying to remember, in which case there would be no apparent need for the supernatural to transmit to the brain.

Similarly, the processing of information, as required in the various tasks, occurs in the brain. So, although we are aware of ourselves trying to recall, imagine, etc., there would be no need for the supernatural to do anything in these tasks except to produce awareness of them. Its only apparent task would be to translate certain parts of brain activity into conscious sensations.

Whatever its role may be, there are two types of problem in invoking the supernatural as a necessary component of consciousness. One relates to evidence. There is no scientific evidence for the existence or characteristics of anything supernatural. While many people, probably the majority, believe in the existence of some sort of supernatural entity, there are great differences in what they think the supernatural is, and no way of resolving how the differences might be resolved. This does not disprove its existence, but casts doubt upon it.

Then there is the problem of transmission of signals between the material brain and the supernatural consciousness. If it were assumed that the supernatural could actually be in a particular place, then bits of it might be situated at each synapse in the brain, in which case it would be either reading the brain directly or duplicating all of the brain’s activities as consciousness in parallel with the brain’s intelligence. This could provide two-way communication. Bits of supernatural would have to be either added or removed as each neuron was established or removed.

Alternatively, there might be some transmitter, and possibly receiver, in the brain, even if we are unable to recognise it. If so, we might expect other consciousnesses to listen in. (Psychics claim but are unable to demonstrate that some brains, or minds, can read others, even when out of sight.) Perhaps each has its own unique channel, like a point-to-point radio system.. And if consciousness remotely reads the brain why does it not also sense other aspects of the material world?

It may well be intrinsically impossible for us to know what process a supernatural entity might use to interact with a brain. No system in the brain that might transmit to or receive from a supernatural consciousness has yet been reported. Presumably there would be electrical fields resulting from the neurons "firing". But neurons also fire when the unconscious mind is operating, so why are we not conscious of its operations? There are also electrical fields generated by other organs of the body, and by inanimate processes of the environment.

All these suppositions are inscrutable. The need to propose them, or some other possible process, weakens the case for the supernatural having a role in consciousness but does not necessarily mean that we must dismiss it. What would confirm it would be some kind of evidence. What would effectively dismiss it would be to show how the processes of the brain could provide all the types of awareness that have been discussed.

How Could the Brain Produce Consciousness?

If consciousness is purely the operation of systems within the brain, then there should be an explanation of how those operations produce sensations – of being alive, of redness, pain, itch, sadness, awe, etc. One way of looking for an explanation might be to explore how consciousness could have evolved from minimal beginnings in primitive organisms, and developed along with intelligence. But this approach still needs to describe a process by which the primitive consciousness was produced by the primitive organs of sensing, remembering and deciding, and how consciousness was evolutionarily useful. But it doesn’t seem possible to know what the content of any primitive consciousness might have been, even if the physical processes were known, so this approach does not seem useful.

Another approach is to start with the characteristics of a complex brain with a complex intelligence and a rich memory, where very many details of both brain and aspects of consciousness can be correlated. One difficulty with this is that the material processes in the brain are all of the same kind, ie., interactions between networks of neurons in the presence of neurotransmitters, whereas conscious sensations seem to be various and very different in kind. What is there in common between an itchy ear, a feeling of elation and the colour yellow, except that we can be conscious of each, either separately or at the same time? What does any of these have that could arise from neuronal networks?

It may be argued that digital data can be used to encode text, music and pictures, and also to perform all sorts of logical and mathematical reasoning, so pulses of data through neurons would do the same. But this is still in the realm of information and intelligence, not of conscious experience.

In addition to producing intelligence and the unconscious mind, neurons have a vast array of non-mental functions such as stimulating and coordinating muscular action, causing the release of hormones and neurotransmitters, regulating the heart-rate and other body processes, and interacting with the immune system. So the neurons perform a lot more work than what is associated with the conscious mind. The unconscious mind and other functions of the brain can be demonstrably explained in terms of the operations of the various parts of the brain and body, including the connections of networks of neurons.

We have no consciousness of what the housekeeping and other neurons are actually doing to produce these particular functions, but we can explain how they do it. So the inability to explain how neurons and other parts of the body might also produce consciousness is a real problem for the materialistic explanation.

The characteristics of subjectivity of all kinds are described in the science of phenomenology. Correlating these descriptions with patterns of connections between nerves does not explain how the sensations arise from the connections. The argument put by Douglas Hofstadter referred to earlier, that consciousness arises from continued feedback of the outputs of networks into themselves, seems to me to be a reasonable explanation of intelligence but not of consciousness. I know of no other explanation. Perhaps neuroscience and phenomenology may some day be able to combine and find one that can demonstrated.

Another way of answering the "hard problem" might be found using reverse engineering, ie., looking at the characteristics of consciousness to work out what type of process might have produced them. But, taking any one of the various kinds of consciousness, say, itchiness or redness, I am unable to imagine a process that might possibly produce it using neuronal connections.

This may be because subjectivity seems, or "feels", like the primary element of our existence, from which all our concepts of the material world emerge. Or it may be that sensations can be described only in terms of other sensations, just as material processes can be described only in terms of other material processes. This would mean that there could be no material explanation.


So now, noting the distinction between consciousness and intelligence, I have examined five explanations of how consciousness could occur. None seem able to justified by evidence and reason, but two may be more promising than the others. I think that until one can be demonstrated to be feasible, or until all but one can be completely refuted, or until some other explanation turns out to be satisfactory, the hard problem of consciousness remains hard.