Perception

All our knowledge has its origins in our perceptions.[10]

I have inserted this chapter as Julia turns eighteen as it provides a quick summary of my philosophy of perception that was not accessible to the five year old I began to write for; but my concept of perception implicitly informs the remainder of this essay.

Philosophers discuss perception within two traditional contexts:
Epistemological, the philosophical theory of what we can know; and
Ontological, the systematic account of entities that are assumed to exist in the epistemological context (and the relationships between them).

This is, of course, jargon.  Jargon is the shorthand used between professionals in a field of knowledge.  It has the, sometimes deliberate, effect of excluding those who do not possess the same esoteric (possessed by a few) knowledge.

In a contemporary information management context we have a parallel: Data, a collection of facts - like a list of people and their telephone numbers; and Metadata - data recording how a system stores, processes and retrieves that list. 

You needn't be bluffed by jargon.  For example, most of us these days can understand once obscure medical jargon.  So you and I and almost everyone who has visited a hospital now knows that 'cardiac' relates to the heart (thus myocardial to the tissues of the heart muscle and so on) and 'oncology' relates to tumours and/or cancer. 

Remember, we are all humans and with a modicum of education and a little bit of application most people of above average intellectual ability can understand almost any concept, short, perhaps, of advanced mathematical physics, that anyone else can.  You just have to commit the time and effort.

Thinkers, philosophers, at least as far back as Socrates and probably tens of thousands of years earlier have known that we each construct our own reality. As Descartes and more extremely, Bishop Berkley, pointed out we cannot be certain that anybody, or anything, exists except ourselves. Berkley thought that perceptions only remain consistent from one time to another and (apparently) from one observer to the next because God moderates the process.

There are as many variations on the theme of perception as there are philosophers. Plato thought that there was a higher reality than that we immediately perceive. Hume argued for a position of scepticism in which we cannot be sure of anything; more of this later.

Some assert that the world exists just as they perceive it. This is called a 'naive realist' epistemology. I think this is demonstrably wrong. I think the indirect realism of Ayer and Russell[11] is closer to the truth.

It seems uncontroversial that we do not perceive the world as it 'really' is. We are relatively easily deceived. We accept a series of still photographs as a moving image. We can be made to see the same photograph or movie two different ways; to feel ice as hot; to think salt is sweet; to fear the harmless; to fail to perceive harm; to be tricked by sleight of hand; and many other illusions.

Of course I, like you I imagine, can conjure up fantasies in my imagination. But I can generally tell the difference between dreams, fancy and fantasy and my day to day surroundings. I regard those that can't, perhaps due to the effect of drugs or mental illness, to be psychotic or to be temporarily deceived or deluded. And I know that a little brain damage or drugs often induces delusions of this kind.

I am persuaded that you are reading this and therefore exist and you and others have similar perceptions to mine. Although we all inevitably see, hear and smell the same cat differently, depending on timing, lighting and relative position; to say nothing of experience, prejudice and knowledge; it is nonetheless the same cat.

Similarly, I know that I can't see a cat in the infrared or ultraviolet unaided; I can't see the bacteria on its skin. I can't smell it as well as a dog can or hear it as well as a bat. Without testing I know little of its health or breeding. In fact, I don't perceive very much about the cat at all; so if I don't simply ignore it, I need to make a lot of guesses about it to fill out my picture: where has it been, what might it do next? I know that some of my mental story might be similar to yours but very probably there are major differences in our accounts.

I don't just do this for cats. My brain is running on doing this for everything in my perceptual field. It is constantly separating and individualising objects from my visual and auditory fields; mostly without ever bringing the objects to my conscious attention. Why do I regard the cup as separate to the saucer and both as separate to the table? Someone who has never experienced a cup and saucer or table might assume them to form a single object. I can often think back over a recent experience and realise that I noticed a lot more about it than I brought to my conscious mind at the time. Where did I leave my keys?

While I am awake my brain is continuously processing my perceptions and building a 'world view' from them.

When watching TV, even though I see a two dimensional moving picture created by pixels changing brightness and colour my brain has no difficulty identifying the Prime Minister on the news or in saying how many people there are on screen. Even in the middle of a party I can listen to one person or to another in the general cacophony.

My perception of time is even more complex and mediated by my brain. Suppose I want to see a speeding bullet. I know the fastest thing I can see needs to be held within my field of view for about a twentieth of a second, so I can't see it directly. I need to set up an apparatus to photograph it. I will probably follow the usual method of a very short duration flash or a very fast shutter (and suitable optics) and I will get a nice picture like lots you can see on the Internet.

If I want to photograph something even faster I need better equipment. Nowadays even individual atoms have been 'filmed' moving about using a succession of very fast photographs.

So the 'real world', the one I photograph, has a 'present' that is much shorter in time than my 'present'. I might need some very sophisticated equipment to find out if the minimum stretch of time forming 'now' is continuous and infinitely small or if it is a quantum (granular) entity and has a fixed minimum value, determined by the Planck Constant.

When I say 'now' in human terms I really mean a stretch of time during which I formulate the intent to say 'now', assemble my various perceptions and then build my mental story. As we will see elsewhere this could be several seconds or it could be quite short depending on the context. 'Now' is a very fuzzy concept.

If I'm driving at 150 km/h, my present includes a forecast of the immediate future as well as the immediate past, otherwise the world might be a perceived as a series of jerky disconnected pictures (probably very few before one involving a broken windscreen and blood). I can't allow a delay of a second before acting, as in that time I will have travelled nearly 42 metres to my probable death. Instead I allow my skill (brain and body working as one) to take control, I perceive the world to be a continuous moving story in which objects are behaving in a more or less predictable way. I brake or turn before being consciously aware of why I do; but I feel relatively safe. Of course more skilful drivers, and pilots landing a plane, can accurately predict the future well beyond a couple of seconds allowing them to travel at over twice this speed quite safely.

We did not evolve this ability to read the immediate future in order to drive or fly a plane, we need it to simply walk; or eat; or type. All moving animals need it. Watch a flock of birds or school of fish all turn together.

It seems that the present is a very strange place, one we really never perceive. In our minds we live in the past and the future. The present is like the fulcrum of a seesaw that moves long the board under us sometimes ahead and sometimes behind.

Although all animals can do this to some extent, as far as we know humans are the only animals that spend a lot of mental time in the more distant past and future; that make elaborate plans; that savour memories or have regrets. It is not surprising that to some the 'now' of their minds seems so separate to the 'now' of their body.

Nevertheless I am a realist to the extent that it seems obvious to me that the perceptions I have originate in a 'real' world that is essentially the same one that you, and others, perceive albeit from different perspectives and with a variety of differing mental processes interpreting that perception. That real world is the one that is accessible by experiment; that produces consistent results each time it is tested; that contains entities we call cups and chairs and atoms and galaxies; in which apples fall and computers process.

But at the interface we are constantly creating a narrative to make sense of our sensations; our experiences. And all this is mediated by our extraordinary brain that not only interprets the external world but manages and directs many bodily functions as well: how we perceive pain; how fast our heart beats; which hormones wash our cells; are just some examples. How we experience pain; or fear; or happiness; or sexual pleasure is moderated by a process of internal interplay between our brain and the rest of our body.

Medical researchers are very familiar with the Placebo Effect and the need for double-blind testing of new drugs because the test subject's brain is very likely to produce the expected result quite independently of the drug's actual effect, while the researcher is likely to inadvertently reveal which is the drug and which the control; or to misperceive or misreport the results.

The subject's pre-existing state of mind heavily influences the impact of the Placebo Effect. A highly sceptical approach can completely negate the impact of acupuncture for example. But it is real alternative to drugs in many cases. In an MRI brain scan the Placebo Effect can be seen to actually change the subject's physical brain state, and correspondingly, related bodily functions, in the same way as psychoactive drugs.

Thus a sincere belief that a faith healer will cure one, or kill one, can have the same physiological effect as a powerful drug (an effect that has been exploited by witch doctors, faith healers and priests since the beginning of humanity).

Research shows the Placebo Effect is considerably enhanced by appropriate psychological preconditioning. In the modern world this might involve a professional certificate, white coats and medical smells (or a TV Evangelist or parting with a lot of money); in pre-historic times might have involved ceremony, a mystical place, sensory confusion or deprivation, dancing and/or mumbo-jumbo.

That our reality is a function of our physical being (bounded by our body) and our wider environment (interactions, knowledge and ideas) seems obvious. Like a computer on a network, your brain interacts with the environment in which it operates. And like a computer, external data forms part of its inputs and outputs in a similar way to its more direct connections with other parts of your body through your nervous and hormonal systems. An external bionic ear with a cochlear ear implant can restore hearing to the deaf; and a user reports that it seems like a part of their body. A skilled pilot or driver feels their vehicle through its controls, vibration, sound and even smell as if it is an extension to their body. They know how wide or high their vehicle is, they can feel a skid and know if an engine is not running properly. In 'fly-by-wire' aircraft the pilot's feel is restored to the controls so that she can sense an imminent stall or turbulence.

Similarly we may have a feeling about our family extending beyond the bounds of our own being; we sense our child, sibling or partners' pain or joy from the clues and feedback they provide to our experience.

In some situations the external can seem more relevant than the internal and this is particularly the case when it is anticipating or remembering experiences. This applies both in the 'now' of immediate pain or pleasure and in the longer term processing of say, post-traumatic stress, loss or happiness.

Reality must be contextual and for each of us 'reality' has to be a unique experience. But it is surprising how often this mundane realisation is treated as revelation and variously disputed, venerated or interpreted as evidence for people existing beyond our bodies, in philosophical and religious writings.

It seems obvious and trivial that for everyone 'reality' is in our head and for each of us it must be subtlety, sometimes extremely, different. This reality begins when as children we realise we can do things that change our world; we are no longer simple observers. From that moment on, this increasingly complex universe we create in our head; the tale we compose; is the only reality we have. Creating it has evolved to be the main function of human brain, and it ends for each of us when our brain stops.

I can, and I assume that you can, mentally stand outside our bodies or imagine an internal 'homunculus[12]' that looks out through the windows of our eyes. But this does not need to be explained in some metaphysical way.

I accept it as obvious that my computer is quite a small machine but becomes much bigger when I log onto a network. It can connect to vastly more data and can use other computers to do some or all of its processing for it. Thus it becomes part of a metaphysical supercomputer that exists in 'cyberspace'. But I do not think this is heaven or that it departs mystically to another realm. It is still here, CPU fan running, and if I remove the power or injure it physically or even programmatically it will cease to function.

It seems obvious that the same can be said of a person; that each of us participates in an experience that extends well beyond our physical bodies. But I see no reason to believe that this is mystical or that our perception of the 'real' is anything but a local mental process. It need be no more than a purely functional outcome of the physical interaction of around ten billion neurons (more about this later).

Indeed my computer is much more able to extend its 'out of body' processing than any human can. It can functionally tap into many others and carry out substantial parts of its processing within a remote host, without even knowing where this is or how it carries out its functions. We have constructed these machines, and their increasingly complex network of relationships, for this very purpose, so that we too can 'hitch a mental ride' beyond the physical monitor, mouse, microphone, camera, speakers or keyboard.

Using more sophisticated interactive haptic and 3D interfaces, for tactile and visual communication, gamers can already enter a new increasingly convincing artificial reality in 'cyberspace'. And amputees can already use such devices to restore feeling to an artificial hand. The otherwise disabled can partially restore other lost senses (like basic sight) by drafting and stimulating nerves elsewhere, in place of those lost.

But again, I do not pretend that an organised collection of electronic components has some separate 'mind', as opposed to the process in which it participates, or that any of this persists, independent of its physical existence, if I turn it off.

That our mind interacts with the universe beyond our physical body, and forward and backward in time, is a simple matter of fact; if we came with a 'user manual' this would be described as part of our functions; like the functions of any machine. It provides no evidence for a mind-body dualism; or for a belief in another separate, unperceived, metaphysical world.