The philosopher David Chalmers has drawn a distinction between “easy problems” of consciousness, and the “hard problem” of consciousness. According to Chalmers, the easy problems – directing attention, concentrating, etc. – can be solved by finding a cognitive mechanism by which they could occur.
In contrast, the hard problem is: “why do we experience anything?”. In other words, how does a skull full of firing neurons give rise to the rich tapestry of external and internal experiences that we respectively refer to as the world and the mind?
Chalmers believes that this problem cannot be solved by talking about cognitive mechanisms or brain activity. However, I suggest that the hard problem is essentially one of sensation; it is the problem of explaining why we possess an immediate sensory awareness.
If this can be explained, then all the other functions of consciousness – abstraction, reflection, self awareness, etc. – can be explained as further levels of feedback on top of sensation (for more on this see my book, Being and Perceiving).
The Hard Problem of Sensation
The hard problem of consciousness can be reframed as the hard problem of sensation. Consider the visual system: when I see an object, light reflected by that object is detected by my eye, turned into electrical impulses, and converted into a neural representation in the form of a pattern of neurons firing.
That pattern of firing neurons in some way corresponds to the image of the object projected onto my retina. But in addition to the neural representation, I also experience a visual image; I see the object. Why is it that that a neural representation creates a psychological, sensory representation (the percept)?
Why is it that this process gives rise to the subjective experience of sight? Explaining this gap between neural representation and psychological representation is crucial to understanding the relationship between neuroscience and psychology – between the brain and the mind.
Decoding Sensory Constructs
There are two possibilities: either any representation which encodes information gives rise to a phenomenological space, or phenomenology arises from functional interactions within representational systems. The former seems implausible, lending itself not only to dualism but also to panpsychism. The firing of neurons in a specific pattern may give rise to vision, but there is no evidence to suggest that a series of light bulbs flashing in that same pattern would also produce vision.
Furthermore, if phenomenology were to directly arise from the very existence of a physical representation, why should any arrangement of physical matter changing in a pattern not give rise to a sensation or perception which is subjective to that physical arrangement?
The words “subjective to” indicate that a physical representation is not sufficient to generate a phenomenological space – awareness of that representation is a necessary component of subjectivity; of phenomenology itself. I suggest that sensory awareness is not just dependent on the ability to encode information, but also on the ability to decode that information. It is a mistake to think that a percept is somehow created through neural representation – the phenomenological world is created by interpreting representations as percepts.
Deriving Qualia
The phenomenological world is made up of qualia, which are units of sensation (greenness, hardness, loudness, etc.). Phenomena are conglomerations of qualia (e.g., an apple may be a combination of roundness, greenness, firmness, smoothness, etc.). Objects do not exist independently of their qualities. It should also be noted that I am not ascribing objective existence to qualia – softness does not exist independently of soft objects, for example. Qualia are the phenomenological units from which our sensations are composed, and as such they are entirely psychological.
I suggest that the process of decoding neural representations consists of deriving qualia from sensory input, and is thus the process by which the phenomenological world is constructed from brain activity. The biologist Gerald Edelman hypothesizes that the brain decodes sensory input by comparing it to categories of perception which are built up from memories of past experience. However, I suggest that sensory input is in fact matched to the archetypal matrix.
Imagine a computer program which can scan visual input (e.g., from a camera) and identify faces in that input. In order to perform this function, it must possess a template of a face which the input can be matched against; this is the archetype of a face. The computer thus has both a limited perceptivity (the ability to scan its visual field) and the ability to see faces in the data. Together, these two things constitute a limited level of sensory awareness; the computer must be able to literally see faces.
If the ability to scan were increased to take in the whole visual field at once, and the computer was also endowed with the ability to identify geometry and perspective (and thus objects and their position in space), motion (direction, speed, etc.), light and dark, and so on, it would be endowed with the ability to derive qualia from visual input, and would thus possess awareness of a phenomenological space. It would be able to interpret visual input as a phenomenological world, and would thus be able to see.
The same goes for all of the other senses. In contrast, to be unable to distinguish between shapes, sizes, distances, etc., would be blindness. The existence of archetypes is crucial for this process: without an archetypal matrix it would be impossible to interpret sensory input as a phenomenological world. The phenomenological world thus arises directly from the mechanics of the mind as described in the previous sections.
Edelman’s theory that categories of perception are built up from memory has the implication that newborn babies do not perceive a sensory world. By explaining phenomenology through a recourse to archetypes, which are innate, I have provided a mechanism which explains how babies and animals appear able to sense immediately upon birth, and most likely even whilst in the womb.
Edelman also suggests that only higher mammals and possibly some birds possess the ability to actually perceive the world. In contrast, I assert that the fact that any organism with a nervous system more complex than that of a jellyfish can generate specific motor output to specific sensory input suggests that most organisms can discriminate between sensory phenomena, and thus possess an awareness of a phenomenological world.
Sprigge’s Bat
The philosopher Timothy Sprigge attempted to refute the idea that the physical processes of the brain could produce psychological phenomena by arguing that a complete description of a bat’s brain – down to the last neurons and even the interactions of its constituent particles – is insufficient to provide the experience of “seeing” with sonar; in other words, a total description of the bat’s brain still does not give us the experience of being the bat.
Sprigge believed that this demonstrated that there was still something missing from the complete physical description, and that therefore physical processes alone could not give rise to psychological experiences. The question “what is it like to be a bat?” was later used by the philosopher Thomas Nagel to demonstrate that a purely scientific understanding of the brain was insufficient to understand consciousness, which necessarily involves a subjective component.
In fact, Sprigge’s thought experiment has no significance, since it deals with the limits of language, not the limits of physical processes. It is absurd to suppose that a complete description of some thing should give us the experience of that thing. The problem is that the thought experiment has been framed in terms of “information” and “knowledge”, rather than language. In truth, we can only ever possess a linguistic or conceptual model of physical processes; this is the only sense in which “knowledge” or “information” has any meaning.
Science thus provides us with descriptions, not experiences. Knowledge and information consist of descriptions, not experience. “Physical processes do not produce phenomenological experiences” does not follow from “descriptions of physical processes do not produce phenomenological experiences”.
Mary’s Room
A similar thought experiment, known as Mary’s Room, was proposed by the philosopher Frank Jackson, and runs as follows: Mary is raised in a black and white room, in which there are no colours. However, while in the room, she learns from books everything there is to know about light, the human brain and its visual system. She learns everything about the physical process of how different wavelengths of light produce the experience of colour. After gaining this knowledge, Mary leaves the room and sees coloured objects for the first time; does she experience something new?
The obvious answer is that she does – she experiences what it is like to see red, green, etc., for the first time. However, this does not imply that physical processes are insufficient to give rise to psychological phenomena; as with the bat example above, it only demonstrates that descriptions of a physical process do not give rise to the same phenomena that the process itself gives rise to.
However, although Sprigge and Nagel’s bat and Jackson’s room do not demonstrate that physical processes are incapable of giving rise to psychological phenomena, they do demonstrate that (1) a scientific description of physical reality tells us nothing about the phenomenological world, and (2) there are certain kinds of knowledge which can only be gained through experience, and not communicated with language.
It is possible to say, therefore, that a complete description of the physical processes of the brain and its interactions with the physical world is not a full description of consciousness or phenomenal experience, because a subjective description of what it is like to be a conscious being experiencing a phenomenal world would be missing, and in fact impossible to formulate. However, this is not an argument against physicalism – it deals entirely with the inability of language to convey subjective experience and the fact that descriptions of physical reality are not reality itself.
Copyright © Dan Haycock 2011. For similar articles and information about Dan’s forthcoming book, Being and Perceiving, visit http://www.DanHaycock.co.uk/writing.html