Wednesday 6 April 2011

How do we Experience the World?

            In my previous post entitled What is love? (Part One) I made use of the idea that we have no direct experience of the external world. Remember these famous words from the first Matrix film –

‘What is real? How do you define real? If you're talking about what you can
feel, what you can smell, what you can taste and see, then real is simply
electrical signals interpreted by your brain. This is the world that you know.’

Although Matrix is clearly a work of fiction the above statement that Morpheus makes in an effort to explain to Neo how the Matrix is possible does neatly encapsulate the current model suggested by neuroscience. Our senses take in forms of energy from the outside world, converts them into electrical signals and feeds these electrical signals into the brain. The brain then grabs hold of these electrical signals and creates an internal representation of the world based on the information embedded within these signals.
 So as a consequence of this we don’t in effect have any direct experience of the external world. Take our sense of hearing for instance. Our ear drums vibrate in response to sound waves. These vibrations are then converted into electrical signals by the cochlea and fed into the brain via the auditory nerve.  The brain then interprets these electrical signals and creates our sense of sound. The sensation of hearing – what we actually hear in our head – is quite separate from what is going on externally in physical reality. To realize this fact ask yourself the question what do vibrating air molecules really sound like?
           Displacements of air molecules can’t really sound like anything at all when you think about it.  What could vibrating  air molecules possibly sound like?  The sounds we hear in our minds are the subjective aspect of sound. It is what we commonly refer to when we talk about sound. The displacement of air molecules is the physics definition of sound. It is what goes on in physical reality. These are clearly two entirely separate sets of phenomena. The only thing that relates them is a cause and effect relationship.  People invariably fall into the temptation of conflating the two things simply because they are empirically associated with each other in this cause and effect relationship. The objective phenomena of vibrating air molecules ultimately causes the subjective sound you hear in your head. The organs of our hearing system are in effect capturing information that is embodied within the displacements of air and translating this  information into a form that can be understood by the brain. This is how we are able to understand each other when we have conversations. The information is captured within the process. Similarly with sight, the colours are not physically out there in the objects we see. They are created within the mind in a similiar way. Physical reality only contains different frequencies of light, or electromagnetic radiation. The frequencies reflected by objects that enter the eyes are what forms the basis of the colours we see. But the colours themselves are not really out there. The optic nerve simply carries electrical signals to the brain, not light. We never see light, which physics tells us is simply the fluctations of an electromagnetic field.
                    The same principle is true of all the senses.  What does a particular configuration of molecule smell like? The question simply has no meaning. The world presented to us by physics is one of odourless, tasteless, colourless particles. The mental representations we all experience in our minds adds on all these  other features, which appears very convincingly to us to be out there in the physical world. 
                 The statement referred to above from the first Matrix movie is making reference to this very fact. It is this idea of how we apprehend the external world around us that motivated the well known philosophical conundrum If a tree falls in a forest and no one is around to hear it, does it make a sound? There is sound from a physics point of view of course since the falling tree will generate displacements of air molecules irrespective of whether someone is present or not. In terms of subjective sound, what we hear in our heads and what we usually refer to as sound, this will not of course exist. It is in this subjective sense that an unobserved falling tree will not make a sound.
            All of this has profound implications. Each of us supposedly lives solipsistically in our own little worlds of mental representation. The external world is unreachable - to all of us. All we are directly aware of is what our minds choose to create in response to certain forms of energy which are constantly impeding our senses. Neuroscience also tells us that our brains even create our sense of time and space! It is all beginning to look a bit like the Matrix isn't it?
            I mention all this because this idea of how we apprehend the external world is something that I will bring into question in my series of posts entitled ‘Are we all part of the same entity’. For some years I have accepted this model without question. It is after all implied by our best understanding of how the brain and mind work and also by our current model of physics (actually I should say Newtonian physics but more on this later as well). It is the solipsistic aspect of this model that I particularly bring into question in my discussion of whether we are part of the same entity. But once this aspect is questioned it starts to bring into question the validity of the whole model itself. How can we in any way experience a shared reality if this model is correct? I feel however that an appropriate analysis of language and meaning, particularly in relation to the question of how it is we are able to communicate our inner thoughts to each other, demonstrates beyond reasonable doubt that something is fundamentally wrong with this model as it currently stands, however convincing it might seem to be.
           I should probably draw attention at this point to the fact that this model in itself doesn't necessarily commit one to the notion that we are all experiencing different things within our minds. Perhaps if  I were to jump into someone else's mind and directly observe their representation of the world it would perfectly match  the representation I experience, and everyone else's to. For instance my version of the colour red is the same as your version of the colour red and everyone else's version of the colour red. I don't see green or some other colour whilst you see red for instance. Perhaps this is the case because our brains are somehow 'programmed' to respond the same way to the same stimulus as some people claim to be the case.
           Also the description of the model above appealed exclusively to Newtonian physics (as opposed to modern day physics) which presents an obsolete and completely erroneous worldview. Newtonian physics is still used for pragmatic reasons but any appeal to this 18th century Newtonian model in order to explain perception is entirely misplaced. In a sense I was playing devils advocate. I don't believe this is how things work at all. My point here was to show where our current conception of things seem to lead us. I later show that this conception of how things work must somehow be incorrect. It is not compatible with certain facts of the world. I believe we do experience a shared reality, but the way this happens is fundamentally different from anything described above. It has to be in order to fit into all the observable facts of the world, which hopefully I will make very clear in future posts.  
           The reason I allowed myself to use this model in my previous post is because the validity of this model is not relevant to the particular points I was making in that post. It was simply a convenient frame of reference to use in order to elucidate certain points I was trying to make. It seems reasonably applicable in that context  also since everyone who embraces the generally accepted understanding of how the brain and senses work will implicitly encapsulate the notion that our reality is grounded exclusively within our own personal mental representations of a strictly out of bounds external world (although of course not everyone accepts this idea explicitly). The thrust of my argument was levelled against what we believe we understand when we talk about love and not what it actually means in reality.

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