The Limits of Imagination

RITA CARTER

This article first appeared in Human Nature - Fact and Fiction
Continuum Books 2006

HUMAN IMAGINATION, WE HUMANS IMAGINE ,  lifts us above other creatures because it allows us to spring free of the here and now. A mental excursion to Narnia or Brobdingnag, Middle Earth, Discworld or Lyra’s Oxford suggests that it is practically unbounded; that in our mind’s eye we can travel beyond the range of memory, defy the laws of nature and slip free from the limits of biology.
    If this were so – if our minds really could float free of the material world – there would be an aspect of each of us that is transcendent. It would justify human claims to be ‘special’ among animals.
    When human imagination is scrutinised, however, its limitations become apparent. Our flights of fancy are slotted into existing conceptual templates – notions of time, space and embodiment – which are physically encoded in our bodies. These force us to see both the ‘real’ world, and the worlds we dream up, in a particular way. If our bodies (and particularly our brains) are structured normally we will never imagine anything that we could not, in theory at least, experience in reality.
    We cannot, for example, imagine an eight dimensional world. Mathematicians tell us that we probably exist in one, and we may believe them, but we will never imagine it because our bodies extend into only four dimensions. Nor can we imagine a true abstraction – infinity, or idealised justice – because our symbols are grounded in sensation. And the only sensations we can imagine are familiar ones. Try as you might, you will never be able to imagine ‘seeing’ as a bat ‘sees’, or ‘hearing’ like a whale.
    Imagination seems at first to be quite distinct from perception of the external world – the sort of here and now awareness we assume we share with all sentient beings. Whereas I feel that I can make anything I like of my fantasy world, my perception of ‘reality’ is non-negotiable. I see a blue mug on the desk in front of me because it is there, and it has intrinsic qualities which make it look blue. I am inclined to assume my cat sees it too, in much the same way.
    People’s visual perceptions are usually so alike that they are for most intents and purposes identical. If a group of people were to be presented with the light waves that are bouncing off my blue mug, for example, it’s unlikely that one of them would exclaim ‘There’s a hippopotamus!’ while another protests: ‘Rubbish! It’s clearly a carrot’. All of them would probably say that they saw a blue mug. Close interrogation might reveal that one of them sees a slightly greener-blue mug than another, but the differences would generally be unimportant. Not only that, but all the people would see the blue mug in the same way: which would not be an x-ray view, or a view of it as seen by a heat-detecting camera, or a view of it as seen through an electron microscope.
    Yet perception is itself largely imagination. Our close consensus about what’s ‘out there’ obscures the fact that what each of us sees is not ‘given’ but individually constructed. Perception is the end result of a creative brain process which can be likened (up to a point) to product assembly in a factory. At one end raw materials – light rays, sound waves, molecules and vibrations – come in via our sensory organs, and at the other end there emerges the finished products – thoughts, emotions and sensations. The reason that the external world appears similar to us all is not because there is only one way to see it, but because the assembly lines in our brains are so alike that we all manufacture it in a similar way.
    Our human consensus encompasses not just our perceptions of concrete objects, but also the way we see things in a more abstract sense, right up to sophisticated issues of social conduct. Despite the fact that human beings grow up in vastly different environments, practically all of them agree that food is good, a roaring tiger is frightening, a smile is more inviting than a frown; that pain is nasty and murder wrong. This common view is an evolved way of seeing things. It is the one that best equips us to survive. If our survival needs were different, our view would be different too. The mug on my desk looks blue to me because my visual apparatus has evolved to distinguish a wide range of colours, presumably because this gave my ancestors some advantage in foraging for food. The light waves from the mug are those that generally give me a ‘blue’ experience, but they do not do that necessarily. Despite my casual assumption that my cat sees things much as I do, it is actually very unlikely that the mug is giving him a ‘blue’ experience comparable to mine, because his eyes and brain do not process light waves in the same way as mine. In this, as in many other things (the fun potential of a mouse on the bed, for example) the cat and I do not share a common view of reality. We see things differently because we do not make the same of it. Human physiology dictates that we see things as we do, just as a cat’s physical form and function dictates that they see mice as delicious playthings.
    In order to make anything of the stimuli from which we construct experience we need to interpret them, using pre-existing concepts about the world. By concepts I mean any sort of knowledge, prejudice or disposition: memories, beliefs, ideas, even the species-specific distribution of cones in the retina that cause me to see blue where my cat probably sees grey.
    Concepts, in this sense, are both mental processes and physical states. Recalling a personal memory, for example, involves the activation of a distinct (though constantly changing) neural firing pattern within a distributed system – a process. If you call up the last sight you had of your mother, the brain areas which will be activated include the hippocampus, temporal cortex and parts of the visual cortex. This combined activity is the neural correlate of the image you see in your mind’s eye. But the memory also has a physical existence, of a sort, even when it is not being recalled. This is because the neural firing pattern correlating with a memory is largely preserved from recall to recall by physical linkages between the relevant cells. Each time a particular neuronal firing pattern occurs the cells involved form stronger bonds between their axons and dendrites. In the case of long-term memories (the ones you ‘relive’ in recollection, or hold as known facts) the neurons involved are located in the association areas in the temporal lobes. Although it requires systemic activation – that is, other areas, such as the hippocampus or prefrontal cortex, need to be active in order for these patterns to fire up – long-term memories can be triggered just by stimulating a cortical ‘storage’ area with an electrode. If you had a sensitive enough microscope and knew what to look for, you might even be able to discern the shape of a memory, woven like a cobweb in the dense tissue of the cortex.
    Before a concept can inform perception, it has to be switched on. That is, the neurons in the pattern which encodes it needs to be firing. If they are firing rapidly (more than 40 times a second) they become conscious, but even when they are firing at a lower rate, and are not therefore actually ‘in mind’, they can still influence behaviour. Certain concepts are more or less permanently ticking over at this subconscious level throughout our waking life. If we lost them we would lose our ability to ‘make’ anything of the world at all.
    To see a visual image, for example, we need an operative concept of space. You might think that such an idea is unnecessary because space is simply there – you don’t have to invent it in your head before you can be aware of it. But this is not so. Our brains are primed to be aware of space – the parietal lobes contain a sort of spatial template closely associated with the body maps which grant us awareness of our bodies. Because the idea of space is thus physically encoded in our brains, it is vulnerable to physical injury. Certain types of brain damage produce a condition known as neglect, in which the individual loses awareness of one or another ‘chunk’ of space and, with it, awareness of any objects within that space. The most common type of neglect involves the loss of one half of the visual field, but sometimes it is ‘near’ space (the area immediately surrounding the person’s body) that is lost, or ‘reaching space’ (the area within the stretch of their limbs).
    A person’s ignorance of a ‘neglected’ area is more profound than if they were blinded to it – it is not just that they can’t see it, they don’t realise it is there to be seen. Neglect is probably not caused by erasure of the concept of the neglected area of space, but by damage to the attention system which prevents people from activating the neurons in which the notion is encoded. Several studies of affected persons have shown that – even in their mind’s eye – the lost area cannot be accessed. For example, when a patient with left-side neglect was asked to describe an imagined walk from the south coast of England to the Scottish Highlands, she named only the towns in the east on the way up, and only those on the west on the way down.  Our concept of space is only useful so long as we can tell one bit from another. We have to know that ‘here’ has a particular relationship to ‘there’, rather than just being different. For that we need to have a mental concept of our bodies which we can place within our mental space. Only when we have placed ourselves firmly within it do we, literally, know where we are. If we did not have this idealised body it would be rather like having a map of a strange town – useless without an arrow saying ‘you are here’.
    Our body concept has to be kept ‘switched on’, at least at a low level, in order for us to use our (actual) body appropriately. It remains ‘on’ by being constantly stimulated by incoming sensory information. Some of this comes from outside. When we walk, for example, the pressure on our feet tells us how our bodies are interacting with the floor. But most of the information is proprioception – a constant stream of messages coming from our joints, muscles, and the movement detectors in our middle ear. This information impacts on the conceptual body and changes it from moment to moment, keeping our inner sense of our body lined up with what is happening to the real thing. The concept, though, is always just a little ahead of the reality. It takes the information coming in ‘now’ and uses it to construct a model of how our body will be a split second later. This is just the time it takes for the concept to become conscious, should it do so. Therefore, when we become conscious of our body it seems that we are conscious of it in ‘real time’. As we feel our weight shifting from the pushing foot to the stepping one in our walk, for example, our body concept is altered to match what we expect when the stepping foot hits the ground. Most of the time the prediction is so good that the real experience is more or less indistinguishable from our idea of it. Indeed, we don’t have to take account of the external information at all, because we have already incorporated its effect into our concept, which ticks along, getting us about the place, without becoming active enough to be conscious.
    However, if we put our foot down a hole and produce a sensory experience that clashes with the predicted concept of how our body is supposed to be at that moment, the concept has momentarily failed and needs very quickly to be re-arranged. To do that the brain has to extract as much ‘real’ information as possible, in order to construct a more realistic internal model. At such times the neural representation of our body – caught in the act of incorporating new information into itself – becomes excessively active and flares into consciousness. Once the model is happily re-harmonised with the outside world it slips back into tickover mode.
    The distinction between our conceptual body and the real thing is manifest most clearly in sleeping dreams or waking ‘out of the body’ experiences. In sleep, the signals from the body that normally keep the two things – concept and reality – closely yoked are blocked off, so our dream body is just our concept, uninformed by proprioception or external stimuli. Hence our experience of it can float free of the flesh.
    The most basic feature of our body concept is its boundary – where it begins and ends. Although the conceptual boundary is plastic in that, as in dreams, it can detach itself from the physical boundary, it is not easily breachable. We have an extremely strong concept of our bodies as whole, integral, undamaged entities, and it doesn’t adapt easily to change. When someone loses a body part through amputation, therefore, it is common for them to continue to feel it, in the phenomenon known as phantom limb. When people with this condition say that they can ‘feel’ their lost arm, what they are actually conscious of is the concept of that arm – which is still securely lodged in their brain.
    Conversely, if the concept itself is partly lost, consciousness of the matching body part will be lost too. Stroke patients who suffer damage to the body map in their brain become partially paralysed, either because the signal pathways between their real body and their conceptual one are broken, or because part of the body concept is itself wiped out. In the latter case, patients seem to lose not only feeling and movement in the affected ‘real’ body area, but also the sense of owning it. It moves beyond their body consciousness, becoming an object ‘out there’ rather than an integral part of their selves.
    The idea of our body – and the related concept of space – might seem to be the most deeply ‘plumbed-in’ concept we have. But in fact there is another concept that is even more taken for granted by humans: that of time. Like space, it seems absurd to think of time as an idea. It seems just to be. But if that were the case – if time proceeded at its stately pace without any conceptual input – it would pass at the same pace for each of us, whatever our circumstances and whatever the condition of our brains. And that is not the case. Even in common experience we find that time does not proceed smoothly. Anyone who has ever been physically involved in or witnessed a traumatic event will know the sensation of time slowing down. Conversely, when we are tired and struggling to do the things that need to be done in the day, time seems to fly past us, leaving us constantly in its wake.
    The notion of flowing time is encoded in a neural circuit in the brain fuelled by the neurotransmitter dopamine. Each ‘loop’ of activity takes, on average, one tenth of a second to complete, and events registered by the brain within the duration of a single loop are experienced as a single occurrence. If the activity in the brain’s time loop slows down, therefore, events get compressed in subjective time, so everything seems to go faster.
    Such variations in subjective time are not usually great enough to affect our ability to function, but if the timing mechanisms in the brain are severely disrupted by illness the effect can be disastrous. People with Parkinson’s disease commonly have a completely different idea of time to everyone else, because their internal clock is slowed down by their insufficiency of dopamine. If you ask most people to say – starting at a certain moment – when they think a minute has passed, their answer, typically, will be to say ‘now’ after about 35 – 40 seconds. Parkinsons’ patients (without medication) are likely to opt for a far longer duration.
    The concept of time can be disrupted by damage to any part of the neural loop that comprises the brain’s internal ‘clock’. One 66-year-old man, for example, found one day as he drove to work that the other traffic seemed to be rushing towards him at terrific speed. And he simultaneously felt that his own car seemed to be going unusually quickly. Even when he slowed down to walking pace it seemed to be hurtling along too fast for him to control it. He found that he couldn’t watch TV because things happened too quickly for him to keep up with them, and he seemed to be perpetually tired. When doctors tried the ‘60-second’ test on him, he waited nearly five minutes before saying ‘time up’. A medical examination revealed that the cause of his problems was a growth in the man’s prefrontal cortex.
    Subjective time may even stop altogether. Damage to the basal ganglia and/or frontal lobes sometimes produces a state known as catatonia, in which people may become ‘frozen’, like living statues. Some such affected persons have been paralysed in mid-action, their hand outstretched as though to reach for something, or contorted into strange postures which they may hold – despite what would normally be severe discomfort – for days at a time. Although they do not appear to be conscious during this time, some patients have later reported that they had memories of it, but that their recollections lacked any sense of passing time and that their consciousness was utterly still and devoid of possibilities. A sense of timelessness – though starkly different to that of catatonia in that it seems full of possibility rather than empty – is also reported by people in meditation or trance.
    At the other end of the scale, people whose brains are suddenly thrust into overdrive, experience an acceleration in subjective time, with a corresponding deceleration of events in the outside world. This is what happens when excitatory chemicals flood the brain during terrifying experiences like accidents, or thrilling ones like a first parachute jump. Suddenly consciousness becomes very clear, with each tiny change in the environment noted and considered. Even when the experience is awful, it delivers an overwhelming sense of being alive.
    The sharpening of consciousness experienced when the brain is excited gives a hint of how our concept of time dictates what we are aware of. Our normal idea of the present moment is equivalent to one of the ‘temporal packets’ or ‘ticks’ of the internal clock – around one tenth to one fifth of a second. Each tick is the time it takes for the current to run around a loop of dopamine-producing cells in the brain. All the information we process during that time-window is experienced as happening simultaneously. This is probably, at our human scale, the optimum ‘size’ of the time packet which is available for us to make sense of things. It means that when a cup falls off the table next to us we see the object hit the floor at the same time as we hear the crash, even though – as light travels faster than sound – there is actually a minuscule gap between the visual stimulus entering our brain and the auditory one. It also allows us to ‘smear’ time, fleshing out the subjective moment by squashing into it all the events that fall into a particular time packet.
    The drawback is that each of our moments is slightly blurred. When we watch the beating of a fly’s wings, we cannot see each individual flap because several of them happen in each of our time windows. The result is that we see a fuzzy haze rather than a clear outline of a moving wing. If our subjective concept of time was more fine-grained, allowing us to split each moment into many more parts, we would see things more clearly. That we have not evolved to do so is probably because such clear-sightedness would burden us with more information than we need. After all, what advantage is there to seeing the individual beats of a fly’s wing? The things we need to discriminate most clearly are those that happen in seconds (animals moving or, today, cars bearing down on us) – not milliseconds. Just as there is no need for us to experience all the visual details that our brains detect unconsciously, time experience is most usefully cast in relatively broad brushstrokes. Only when we are faced with a life-threatening situation, or one which is wildly exciting, can we afford to ignore everything in the past and future and concentrate on the present moment And when that happens our brains oblige by breaking the moment into more parts so each one can be separately scrutinised and dealt with.
    In addition to the fundamental concepts that mould our experience, we each have a huge database of individual memories which give shape and colour to everything we perceive and imagine. Each one begins as a tiny ‘seed’ of sensory experience. The concept of a dog to a baby, for instance, is probably no more than a particular sensation – the waft of hot doggy breath or a big moving shape. But over time it becomes more and more complex. The doggy sensation becomes ‘furry thing that goes woof!’ and then grows to be hugely elaborate, incorporating ideas about different breeds of dog, the history of dogs, the biological characteristics of the genus canidae and so on. It may also be linked to other concepts: dog-days and dog-fights, doggie-bags and dogged people, dog-lilies and dog-ends, so that when any one of these ideas crops up it drags with it a whole host of associations.
    Most of the things that happen to us get forgotten almost as soon as they happen. But some of them stick in the mind as memories, or act on existing concepts to alter them. The ugh experience of eating a bitter fruit may not itself be remembered, but it might leave a permanent mark by changing or elaborating an existing idea about apples.
    The concepts formed by memorising certain experiences and conjoining them with related ones provide a massive database of knowledge that can be brought to bear on new experiences, and therefore affect behaviour. Take, say, a memory of a being bitten by a dog. It will be bound in with existing memories of dogs – of hairy bodies, wet noses, Rover, and so on. Any experience that occurs thereafter which ‘hooks’ onto these peripheral memories will therefore also bring to mind – consciously or not – the memory of the bite.
    So a new experience of a dog will be attended by a certain degree of caution. There is, however, a limit to the usefulness of such knowledge so long as it can only be accessed by a reminder that is purely sensory (the experience of a wet nose). The concept that ‘dogs can bite’ remains locked away until it is needed – right here, right now. It cannot be used to predict what might happen in the future, or what might be happening to someone else, someplace else. In order to make that concept of a dog biting readily available, on tap, it has to be encoded is some way that makes it, so to speak, ‘portable’. The meaning derived from the real event (ouch!) has to be extracted from the memory and put it into a mental vehicle that caters for all events which contain that meaning. In other words, it needs to be symbolised.
    The symbols used by humans to transport such experiences are words. Language – the structure in which words are embedded – can itself be considered as a concept. Rather like the body maps which need only to be ‘filled in’ by physical exploration, the structure of language seems to be mapped in. You can actually see the parts of the brain where this language ‘instinct’ is lodged. Wernicke’s and Broca’s areas make a discernable bulge (in right handers) along the side of the left hemisphere. When these areas become active, around the age of two, children start to use language to communicate but – perhaps more importantly – they also start to use it to structure their inner world. Language provides a scaffold for thoughts which, without it, would be amorphous and fleeting. It allows us to crystallise ideas, to link them to other notions, to encode them in a way that makes them retrievable on demand, to project into the future, and to string thoughts together in a rational and communicable train.
    Once an experience is attached to and encapsulated in a word, therefore, much of the sensory, ‘re-liveable’ nature of that experience falls away, because we now have a way of conveying information (dogs can bite) and thus making it ‘useable’, without having to recall the experience itself. We may even seem to forget the experience and be left with just an idea.
    If ideas could be totally divorced from bodily experience we would be capable of imagining pure abstractions. When we think about things like dogs biting, without invoking a mental image of such a thing, it seems that this is what we are doing. This is not the case, however. Rather, it seems that everything we can imagine has some physical ‘presence’ for us. Every word and every thought is connected to a bodily experience.
    Bodily elements are easy to grasp when we think in images. After all, an image is a sensation. And even the faintest of imagined images is created, in part at least, by a replay of some previous experience, or a juxtaposition of several such experiences. Similarly, the meaning that we discern in music is conveyed through its sensuality – a musical score means nothing if we cannot translate it into imagined sound.
    But what about, say, a chair? We don’t visualise a chair every time we say the word – sentences are not like those dumbed-down TV documentaries where every word of the script has to be accompanied by the matching image. So it is easy to think that the word ‘chair’ is used instead of a sensation, that the ‘felt’ meaning of the object has been transferred into a symbol. That is not the case.
    We learn new concepts by linking them to ones we already have. These conglomerations form categories – living things, for example, may be one category, man-made things another. And categories are organised like Russian dolls. ‘Furniture’ for example, may be nested within the larger category of ‘man-made things’, and ‘chairs’ may be nested inside the ‘furniture’ category. Types of chairs – a throne, say – will in turn be nested within the ‘chairs’ category, and ‘the Bishop’s throne’ within the ‘throne’ module, which is itself inside the ‘chairs’ category.
    If each category is as ‘real’ as any other, a child might first learn about their grandmother’s rocking chair and then learn to ‘nest it’ within the larger category of chair, working from the bottom up. Or in different circumstances they might first learn that there are objects called ‘furniture’ and then learn to discriminate chairs. If the brain was working as a detached learning machine, it really wouldn’t matter which concept came first.
    But it does matter. The ‘chair’ level categories (other examples are ‘tree’, as opposed to ‘plant’ or ‘oak tree’, or ‘horse’ as opposed to ‘animal’ or ‘carthorse) are, in crucial ways, more ‘basic’ to the brain. They are learnt first. They enter language before the others, and are identified faster by nearly everyone. They seem to comprise our ‘default’ picture of the world.
    One reason for this seems to be that this is the highest categorical level at which you, and I, and everyone else who uses ‘chair’, find common meaning through our bodies. I can’t imagine sitting in ‘grandmother’s rocking-chair’ if my grandmother never had one. Or rather, to do so I would first have to create an imaginary rocking chair, imagine it belonging to Grandma, then imagine myself sitting in it, which is quite a conceptual effort. And I can’t intuitively know what to do with ‘furniture’, because ‘furniture’ could be anything from a bed to a bookcase. But say ‘chair’ to anyone and they know how their body would interact with it, because you put your backside on the seat and bend your knees to interact (normally) with every sort of chair. Each member of the furniture category, in contrast, requires a different sort of motor action: lying down (if it’s a bed), opening a door (if it’s a cupboard), placing things on it (if it’s a table), and so on. It therefore seems that the perfect example of any conceptual category is not the one that best encompasses all the others, as you might suppose, but rather the one that best exemplifies the way that everything in the category is physically experienced.
    The way that we store and retrieve concepts also reveals their links to physical movement. Word knowledge is ‘stored’ in the language areas of the brain. But when a person is asked to think of a particular word, it does not just ‘pop up’ from the word bank. Brain imaging studies show that the word’s meaning is ‘gathered’ from wide-spread brain areas, including those that process sensations and plan movements in response to the object represented by that word.
    Strange as it may seem, it is impossible even to think of a word without moving. Language-based thought (and most thought is contained in language) is accompanied by the beginnings of the motor actions required to articulate the words aloud. The area of the brain most closely concerned with speech production, Broca’s area, is essentially a movement area – it triggers activity in the muscles that allow the lips, tongue and throat to produce sounds. When people read, even quietly, alone, to and for themselves, this area produces tiny contractions of those muscles, even if we long ago learned to stop our lips moving. And the amount of muscular activity is not related so much to the complexity of the words that are being uttered, but to the amount of movement implied by their meaning. Reading a list of verbs produces more motor activity than does reading a list of passive words.
    Furthermore, the movement is not limited to Broca’s area. One study found that when people saw words relating to tools – things that they would expect to pick up and use – the part of the brain which would normally plan the body movements required to deploy the screwdriver or the hammer became active, as though the tool was right there in front of the person, just begging to be put to use.  Symbols, then, may be partially abstracted – that is, taken away from the bodily sensations associated with them – but they are never cut off entirely from physical experience. The brain keeps them connected through its elaborate feedback system, by which concepts track back to the sensations and actions associated with them, and actions and sensations constantly form and update their symbols.
    The brain’s creation of ‘action plans’ with regards to objects may be what it takes to make the objects meaningful to us, or perhaps even to make them visible, or imaginable. From this it would follow that if an object has no potential for physical interaction we simply could not form an idea of it. We may very well be blind to many aspects of the world in which we live, simply because we do not create an intention to interact with them.
    It is impossible, of course, to point to things we cannot sense. We can think of such things, as we can think about the possibility of other dimensions, but even in imagination we cannot experience them. There may be surfaces we fail to see because we cannot stand on, move across or place things on them. The surface of a bank of hot air in the sky, for example, may be clearly visible to a gull, looking to hitch itself a ride on a rising current. The fact that it is not clearly visible to humans is not necessarily just a matter of not having evolved the right sensory equipment – experienced glider pilots can ‘read’ the sky in a way that others cannot, just as a fisherman sees subtle changes in the sea which escape landlubbers. Rather we do not have the concept required to recognise these things, in the way that a person with neglect does not have the idea of the part of space to which they are blind. The only sort of awareness we can have of these ‘hidden’ things is what we can derive from existing, ‘near-to’ concepts, much as a blind man might get an idea of ‘red’ by thinking of the rich tone of a bassoon. It is only an approximation, though. To be conscious of the real thing you would have to construct an action schema that involved preparing your wings to glide on the surface. And that is beyond normal human imagination.
    What, though, of abnormal imagination? When people diverge from the consensual view of reality we regard them as either mentally deranged or gifted visionaries, depending on whether their behaviour is socially acceptable or disruptive. The hallucinations, delusions and bizarre behaviour associated with psychoses were once deemed to be supernatural in origin – the work of God or the devil – and in some cultures they still are
    Eccentric ways of seeing the world occur when a person’s brain puts together the raw materials of perception in an unusual way, due to some physical abnormality. The physical difference may be gross – a (literal) hole in the head, like poor Phineas Gage,  or microscopic, a matter of molecular changes in a handful of brain cells. Such abnormalities occur for all sorts of reasons. The person’s brain may have been damaged by injury or disease or affected by some abnormality in another part of the body. It may have developed in an unusual way due to a rare genetic constitution, been changed by some extraordinary event, moulded by weird cultural conditioning, or temporarily altered by a drug. Whatever the historical reason, the immediate cause of a person ‘losing touch with reality’ is an abnormality in the structure or functioning of the nervous system.
    Given that the normal way of seeing things evolved because it best equipped us to survive, one would expect any departure from the norm to be dysfunctional. But this is not always the case; sometimes abnormal biology creates a view that enriches us all. Einstein, for example, ‘saw’ the space-time manifold in an act of imagination that preceded the laborious process of working out the mathematics that confirmed the intuition. One reason for his genius was probably the missing groove in his brain which allowed information to flow between neurons that would otherwise be separated. Several great artists did their best work during periods of mania, a condition associated with changes in the neurochemistry of the brain, and deliberate alteration of brain function through drugs inspired the Romantic poets to some of their most celebrated work. So, although human imagination may be limited by biology – biology is pliable. One day, perhaps, we will learn how to alter it in such a way as to create any experience we desire.

© Rita Carter 2007 - ritacarter.co.uk