For a recent psychology essay I had the rather unreasonable task of answering a question on the nature of consciousness. Is that really fair? That I should have to solve life's greatest riddle for something like 2% of my undergratuate degree?
Well turning a negative into a positive I realised that the essay would possibly be of interest to readers of the the Biomatrix, particularly with its relevance to consciousness uploads. So read on and enjoy but don't expect to find any of the usual whimsy. Think that's heavy going? Try writing the bloody thing.
Is consciousness distinct from the biological function of the brain?
There are several theories on the nature of consciousness, most of which can be categorized as dualist or monist (cited in Velmans, 2000). Dualist theories of consciousness state that it is something separate from, or additional to, the basic workings of the brain and physical phenomena in general. Concepts such as a ‘soul’ or ‘spirit’ are examples of dualistic beliefs. Meanwhile, monism states that there is only one type of substance, with materialists maintaining that this one substance is the physical world we see around us, and that consciousness is tied to the physical workings of the brain. By this reasoning consciousness is no different from any other physical phenomena. There is some evidence and many theories supporting both these camps and currently no widely accepted explanation for how consciousness arises or what exactly it is. This essay will examine arguments both for and against the idea of consciousness as distinct from the functioning of the brain.
The philosopher Rene Descartes (famous for the quote ‘Cogito, ergo sum – I think therefore I am’) was one of the first philosophers to analyse the nature of consciousness in a rational way (cited in Revonsonsuo & Kamppinen, 1994). Here he reasoned that consciousness was separate from the material world as firstly, unlike consciousness, other objects are unable to think or make decisions, and secondly, unlike other objects, it is not possible to describe the properties of consciousness/a thought – for example its location or size (you can’t for example say what colour your ideas are). This offered early support for dualism and gave rise to the school of thought known as ‘Cartesian dualism’ where the physical world is characterised by its extension in space, by which definition consciousness must be something else non-physical. Many religions consider this nonphysical substance to be a ‘soul’ or ‘spirit’.
The belief that humans have a spirit or soul is known as ‘substance dualism’, where consciousness is entirely separate from the body and so in theory could exist independently (cited in Velmans, 2000). This is the stance taken up by many religions such as Christianity where it is believed we have a separate soul that can survive even after the physical death of our bodies to live on in ‘hell’ or ‘heaven’. Incidences of out of body experiences (OBEs) and near death experiences (NDEs) have been taken as evidence supporting substance dualism. An OBE is characterised by a sensation in which an individual feels that they are somehow ‘floating’ out of their body. Sometimes they may claim to be able to see things from a different angle as a result, or even to be able to ‘travel’ in this spirit form while their bodies remain static.
Studies looking into the ability of patients to remotely view pieces of paper etc during out of body experiences have proven inconclusive however leading many such as Susan Blackmore (1998) to claim that nothing actually leaves the body during such experiences. Much like sleep paralysis or dreams, OBEs or NDEs could be caused by unusual activity in the brain. This is seemingly supported by studies that show that OBEs can be purposefully induced in patients (Blanke & Thut, 2007). In particular this has been achieved by magnetically stimulating the temporal lobes of the brain which are known to be related to visuo-spatial awareness, multi-sensory integration and self awareness.
On the other hand, reducing consciousness to the physical activity of the brain (materialism) is a form of ‘reductionism’; the act of reducing phenomenon to their most fundamental aspects. In the philosophy of mind this school of materialism is known as ‘type-identity theory’, where simply: brain state A results in conscious experience B. Here experiences are caused simply by the firing of neurons with specific neurons corresponding to specific sensations. This is seemingly supported by studies where patients’ exposed brains have been stimulated by electrodes resulting in their reporting a variety of subjective experiences including vivid flashbacks (Penfield & Perot, 1963). Further, studies using split brain patients (where the corpus callosum and other connective tissue between the brain’s hemispheres has been severed) has shown dissociation of awareness. For example when shown two words, one in each visual field, they are found to only be capable of reporting those in the right visual field – presumably as the left hemisphere is both responsible for the right visual field and, critically, speech (cited in Revonsonsuo & Kamppinen, 1994). This has been interpreted in a variety of ways; as there being two separate streams of consciousness – one for each hemisphere (Sperry, 1984), or as there being just one – that of the vocal left hemisphere (Gazzaniga et al, 1977). One philosopher, Puccetti (1988), went as far as to claim that we all constantly have two simultaneous consciousnesses but that it only becomes evident under such circumstances.
Regardless, these studies and others focusing on various other forms of brain damage, seem to support the idea that consciousness is inextricably tied to the functioning of the brain. If consciousness truly is simply a function of the brain, then it should be possible for neuroscientists to pinpoint its location and many have tried. Some psychologists have equated consciousness simply to language (Julian Jaynes, 1976), which would suggest that it is seated in the left-hemisphere where language is located (which interestingly concurs with Gazzaniga’s explanation of the split brain patients). Critics of this theory however point out that animals, and even some non-speaking humans (such as feral children or deaf/dumb patients) appear conscious without the need for language. While it is hard to imagine thought without language, it certainly need not be present for ‘choice’ to occur (the ‘intentionality’ aspect of consciousness (Brentano, 1995)) which seems to be a fundamental aspect of what we consider consciousness to be.
Much of our higher brain function, such as language and cognition, seems to be handled by our pre-frontal cortex with the more menial tasks such as breathing being left to our brain stems (cited in Pinel, 2006). It is certainly possible therefore to presume that consciousness might be generated within the frontal areas of the brain and many legion studies seem to support this idea. For example patients in persistent vegetative states exhibit less activity in the cortex, and furthermore this is often as a result of a severance between the cortex and brain stem.
This idea also seems to make sense from an evolutionary standpoint, with more basic organisms having no or small underdeveloped prefrontal cortexes. However is this then to say that they are without consciousness? The danger here is that we mistake intelligence for consciousness. Another popular argument is that consciousness is actually the result of various brain areas functioning in unison and that it can not be isolated to one region (John, 2001).
One criticism for type-identity theory in general however is ‘multiple realisability’, put forward by Hilary Putnam (1967), which points out that while two people or even creatures of different species can have a common subjective experience, such as pain, it is unlikely that this always correlates to the exact same brain state - suggesting that something more must be at play. Token-identity theory however side steps this problem by stipulating that a single instance of a nerve firing correlates only with a single instance of experience as opposed to a more universal correlation.
Steven Sevush (2002) proposed another interesting recent theory that attempts to locate consciousness. Sevush argues that rather than being the result of a complex neural network, consciousness could actually exist within single neurons. He claims that what we consider to be our conscious experience is not the result of a single macroscopic mechanism (the brain) but rather of a ‘chorus’ of individually conscious neurons. His support for this comes from examples of single neurons dealing with enough dendritic information to account for the full range of conscious experience. Certainly single celled organisms demonstrate that life can exist within a single cell, so why not consciousness?
In these materialist descriptions consciousness is often viewed as simply an ‘emergent property’ of the brain, a view sometimes referred to as ‘emergent materialism’ (cited in Velmans, 2000). That is to say that consciousness is simply a bi-product of the physical processes of the brain, and so when the brain dies so too does consciousness. By this reasoning two identical brains would also result in two identical consciousnesses, almost reducing the process to that of a highly advanced computer.
One criticism of this theory however is that an ‘emergent’ consciousness cannot explain causality. That is, if consciousness simply arises from the workings of our brain it shouldn’t be able to affect its working; it would be akin to a television program affecting the circuitry of the TV (Goswami, 1995). If consciousness does not affect the brain however, then surely we are not truly in conscious control of our actions? Intuitively this seems unlikely and is another source of criticism for type-identity and token-identity explanations, yet it goes hand in hand with another school of thought known as ‘epiphenomalism’.
Epiphenomalism, a term originally coined by Thomas Henry Huxley (1874), claims our conscious control is actually just an ‘illusion’ and that we are not really in command of our actions at all rendering us as simple observers. This has been supported by studies such as those of Libet (1982), where participants were asked to randomly move their hands and then report at what time they made the decision to do so (a clock was in view). What was discovered was that the participants actually exhibited a ‘readiness potential’ (a pattern of activity within the brain that signals the intention to move) prior to the point when they reported making the decision consciously. While the study is interesting, there are several methodological problems, including the fact that it will have taken the participants a certain amount of time to read the time which could explain the ‘lag’.
Parallelism describes these effects differently, by saying that our consciousness and the physical world simply run in parallel with no causality at all between the two (cited in Carter, 2000). This is often explained as the work of God; that God made our consciousness awareness and our actions synchronised to give an impression of free will while allowing for a controlled destiny.
Many object to the idea of parallelism and epiphenomenalism on intuitive grounds. Additionally by rendering our consciousness impotent in this way, such theories call into question the purpose of having consciousness at all; for if we are not in control of our actions then what is the point of being aware? Certainly if we have no influence on our behaviour there doesn’t seem to be any survival value for it, which would make it unlikely that it would be a result of natural selection, or even included in the designs of a God. It also calls into question what it is exactly that Christians claim goes to heaven after we die; a spirit devoid of free will whose actions are dictated by God?
However when we consider the amount we can achieve without consciousness – driving a car, brushing our teeth, or even heading downstairs to make sandwiches in the case of some sleepwalkers – it makes one question even more the purpose of consciousness regardless of its role in directing behaviour.
Property dualism, a sub-branch of emergent materialism, describes the way in which consciousness can arise in a slightly different way by comparing it to phenomenon such as light (cited in Velmans, 2000). Light is notable for the fact that behaves both as a wave and a particle. Similarly heat is actually really just movement at an atomic level. Property dualism claims that similarly, when biological matter is arranged in a certain way, it becomes at once physical and conscious. It is possible then that consciousness is a force as yet not fully understood by physics with characteristics that could result in both the physical process of the brain and the mental phenomenon of consciousness.
Quantum mind theory takes this stance further by explaining consciousness as the result of as-yet not understood quantum mechanics. In Shadows of the Mind (Penrose, 1995) Penrose and his colleague Hameroff suggest that ‘microtubules’ present an environment where quantum mechanics could affect the brain at macroscopic levels. The relationship between consciousness and quantum physics is also demonstrated by the ‘wavefunction collapse’, where simply being aware of a sub-atomic particle has been shown to have an affect on their physical position (cited in Carter, 2002).
Critics of this theory however, point out that such an explanation does not solve anything, but rather simply speculates that two unexplained occurrences may be related. Philosopher David Chalmers (1995) described Quantum mind theory as an example of his ‘law of minimization of mystery’, that its supporters took the view that ‘consciousness is mysterious and quantum mechanics is mysterious, so maybe the two mysteries have a common source.’
Similar to property dualism is ‘dual aspect monism’, which describes all matter as being founded on some form of underlying ‘information’, much as the virtual environment of a computer game is founded at the most basic level on binary code. Here consciousness and physical reality are two aspects of the same substance. The ancient philosopher Plato was actually one of the first to make such a claim stating that underlying all of reality was ‘pure reason’.
Considering the implications of quantum physics then, it is not too great a leap to claim that this underlying ‘information’ might be consciousness itself which some recent theories now suggest (Goswami, 1993). Such a theory, ‘monistic idealism’, results in the rather large claim that the entire universe might be self-aware but could also offer support for the concept of consciousness in single neurons. However, this again falls prey to David Chalmers’ law of minimization of mystery, lumping together two unexplained phenomenon without shedding light on either.
For these reasons ‘new mysterians’ take the bleak view that consciousness is simply too complex a concept for the human mind to grasp, agreeing it seems with Ken Hill, famously quoted as saying that ‘if the brain were simple enough for us to understand it, we would be too simple to understand it.’
Whether consciousness will ever be fully understood is impossible to say. At this point there is still no agreement on whether consciousness is something distinct from the functioning of the brain or whether it is simply a byproduct that serves no real purpose. There are still a host of arguments for both monism and dualism as well as everything in between, with no end to the debate in sight. Currently it seems that an alteration is needed in the way consciousness is viewed, though perhaps compromises such as dual aspect monism or property dualism stand the best chance of providing a solution that might satisfy both camps; maybe it’s possible that consciousness can be at once distinct from our brain function and tied inextricably to its workings.
