iankirk.net

A small body of works of cultural theory that addresses medical Images such as X-rays, MRI, PET, Computed Tomography and their variants has emerged in the last couple of decades¹. The rhetoric of these works has tended to assimilate these forms of images directly into a broader discussion of visual culture, often drawing analogies – consciously or apparently unconsciously – with photography and cinema. Of course these images called images after all, so it does not at first seem too problematic to attempt to order them within visual culture.

However, the issue here is one of ocularcentrism. By making medical images analogous to photographs, for example, one introduces various tropes of ‘seeing’ on the part of the apparatus as well as for the view. In their design, and often in the discussion that surrounds them, cameras (either photographic or cinematographic) are considered to be analogous to the eye, and what they produced to be analogous to forms of vision.

At their core, unlike cameras, the apparatuses that create medical images are not modelled on the eye (lenses hardly feature, for example), and make use of physical phenomenon other than visible light. I will argue that medical images are better understood and more productively analyzed from the point of view of cultural studies as form of scientific inscriptions (Latour 1986) or as data visualizations. A number of epistemological and aesthetic issues proceed from this ‘overlooking’ of the nature of medical imaging apparatus and the medical and scientific processes of which they form a part.

Further, a too-ready equivalence of medical images with other forms of notionally representative images such as photographs or realist art means that issues to do with representation, objectivity, reference and resemblance have not been properly addressed, nor has the potentially transformative effect on the body been explored in terms that are specific to medical imaging. In short, a tendency to treat medical images as the same as other forms of media has overlooked important specificities in their own ‘mediality’: what medical images are, how they work.

Equally, in terms of how such images are received and analysed, a prevailing ocularcentrism has encoded a particularly phenomenological approach to their interpretation. Indeed, a phenomenological ontology pervades most discussion of medical images. One hand there is an assumption that the viewer of medical images ‘sees’ what the apparatus ‘sees’ (this is the correlatve of ocularcentrism, that the technological eye and the human eye of the observer are in some ways substitutable), and on the other hand there is the ontological assumption, a kind of essentialism found particularly with brain imaging, that all personality traits, moods, capabilities, talents, and pathologies² can be understood as in some way intrinsic or inherent to the body in question rather than, for example, arising out of situations, events or social forces.

In order to gain a better understanding of medical images as media, it is necessary to consider the technical apparatus that is used to make them, their role as visualisations and inscriptions, the issues that relate to resemblance and representation, the uses to which they are put, the methods by which their meanings and potential referentiality are determined, and the ways in which their subject, the body, is transformed by the existence of this media.

 

1. How Most Types of Medical Images are Made

In order to understand some of the specificities of medical images, it is necessary to describe how they are made. The outlines provided here are intended to draw attention to particular attributes of each method of medical imaging that contribute to their specificities as forms of media.

Before describing each technique, however, it is important to remember that medical images are made in medical imaging facilities. The architecture of medical imaging facilities has to be carefully designed to allow the machines to operate and to protect the operators from, for example, excessive exposure to radiation. The person whose image is being made has to exchange their own clothes for a hospital gown, remove anything such as jewellery that may endanger them or affect the image, perhaps cover parts of the body with protective shields (i.e. lead aprons to protect reproductive organs from X-rays), and often adopt specific physical positions in order to facilitate the production of the image and to hold that position in order to guarantee the fidelity of the image. People are generally required to lie down on their backs or on their sides for MRI or PET scans. They will be required to stand, sit, or lie down for different types of X-ray. Chest X-rays or even elbow X-rays may demand that the person adopts unusual or even uncomfortable positions for specific durations. There is a sense in which the body is disciplined and conditioned by the situation (the doctor’s desire for a particular type of image that will yield the information required, the way in which the imaging system works, safety considerations) so that they enter into the assemblage of image-production. Attire, position, movement, isolation are all part of the person’s becoming a patient at that moment, and are all put into the service of producing the image.

Which imaging method is used will depend on the kind of information that the doctor or researcher requires (and this will itself depend on their own knowledge and expertise), the availability of types of imaging equipment, the available skills of the operators, and the relative costs of making each image. Certain parameters of interpretation are therefore set before the image is even produced. Thus intellectual, social, economic and institutional factors are at play even as the diagnostic intent of the image is being formulated, and before the fact of the image itself.

When considering different technologies and apparatuses for the production of medical images, there are essentially three³ categories of image. These categories of image really describe the type of probe⁴

1) Images, such as X-rays, and CT that are made by passing the probe through the body. In some procedures, the patient is injected with iodine or asked to swallow some barium. These will block the passage of X-rays through the body just like bones and denser matter.

2) Images that put an emitter inside the body. PET are made by putting a radioactive emitter inside the body and then using sensors to detect where it goes. 3) Images that detect physical effects of the body. These can be naturally occurring effects such as with thermography, or they can be induced, such as with MRI.

Within the context of medical imaging, the body therefore becomes a field that can be traversed, made to emit radiation or monitored electromagnetically. In almost every case, the body is required to be still whilst the apparatus moves around or across the body. There is no photographic or cinematic equivalent, since even in cinema the result of a tracking shot would not be a single image. The nearest familiar visual equivalents would be the movement of a fax machine, photocopier or digital scanner. As will become clear in the discussion of Latour, this metaphorical proximity to document technologies rather than pictorial technologies is revealing.

Xrays

X-rays images are made by passing cathode rays (i.e. streams of electrons) through a body. The rays pass successfully through soft tissue like muscles and organs, but are impeded by denser matter like bones. If a ray gets through the body it hits a chemically coated paper and causes it to fluoresce at the point where it is hit. The X-rays themselves are not visible, the effect on the paper is what we see.

In traditional X-rays made without a computer, there is no lens as such. An X-ray cartridge consists has the fluorescent paper on one side and photosensitive paper on the other. The photosensitive paper captures the image of the fluorescent paper. Still X-rays are in fact photographs of a fluorescent image, and are therefore at one further remove from the subject itself.

Although photosensitive paper is present, the production of X-ray images is very different from traditional photography. In traditional photography a lens concentrates light reflected from a subject onto the paper, in X-rays, the cathode rays are usually emanating from one point and fanning outwards through the body, and continuing to fan out as they hit the fluorescent paper.

When we think of X-rays, we normally imagine an image of white bones on a black background. This seems logical to us partly because it’s what we’re used to seeing, and partly because it coincides with what we know about what bones really look like. From a photographic standpoint, however, the conventional X-ray is a negative image. The bones appear white because that’s where the paper did not fluoresce. Were X-ray films to be developed like photographs, we would see dark bones (shadows of the electron beam) and white backgrounds (where the photosensitive paper would have been exposed to a lot of light from the fluorescent paper). The impression that we get that we are ‘looking within’ when we look at X-rays results from a conscious decision not to develop the photographic negative. Their verisimilitude, and any apparent visuality, therefore depends to this extent on their not being treated as types of photographs.

Photography captures reflected light from its subject. Anything that is on the other side of the subject from the camera is obviously not in the picture. X-rays images capture the results of rays having passed entirely through a body. If you kept your keys in your front pocket or your back pocket they would show up on an X-ray because this type of image-making collapses three dimensions into two in an entirely different way from photography or sight.

As is now well known, X-rays are dangerous. It is not always a matter of whether an electron makes it through the body or not. Sometimes the electrons knock out one of the body’s own electrons, ionising the atom concerned. Usually the affected tissue will die (it will seem like a burn), sometimes the mutation will result in cancer, and in the case of sperm, ova or foetuses genetic mutation may result in developmental abnormalities. For these reasons, the frequency of X-rays and their doses is kept to a minimum, testicles and ovaries are usually shielded from radiation, and pregnant women are very rarely X-rayed. What is not so well known is that X-rays occur naturally all the time, and in the course of a few days we will receive as much radiation as in a typical chest X-ray (Wolbarst 1999). X-ray imaging is therefore a the intensity of the radiation received in a short space of time and the presence of the imaging apparatus rather than any extremely exceptional state.

Fluoroscopy and Digital Subtraction Angiography

Flouroscopy is another way to use X-rays, but instead of producing still images like conventional X-rays it produces a real-time moving image (which of course can be recorded to make videos). In this case a video camera takes over the role of the photosensitive paper described above. Here, a ‘condenser’ is used to bring the cathode rays closer together before they hit any fluorescent material. The condenser works a bit like a camera lens does for photons, but it is not an optical lens since we are not dealing with optical particles.

Flouroscopy and modern X-ray images replace photosensitive paper with digital imaging technologies, and it is very typical for these images to be subject to digital alterations such as noise filtering and edge enhancement in the control of the operator.

Digital Subtraction Angiogaphy (DSA) is in some ways an extreme case of this form of filtering. In DSA, very clear images of veins are created by first taking an X-ray of a patient, then injecting their veins with an iodine compound and X-raying them again. The iodine compound blocks the X-rays. Using a computer, the first image is subtracted from the second, so that the resulting ‘difference image’ shows only the veins.

Digital Subtraction Angiography serves as a good example of the essentially diagrammatic intention of medical imaging. For medical purposes, the ideal is not to get as complete and photorealistic image as possible. The objective is to highlight only those areas of interest and exclude any other details that are not helpful. X-rays are mostly hopeless when it comes to understanding muscular damage but they are really useful for understanding bone fractures. A doctor would normally not be helped if an X-ray of a broken arm provided a perfect image of the surrounding muscles. The failure of X-rays to capture that sort of information is what makes them useful in clinical situations. There is no ideal of perfectibility in relation to medical images and so aesthetic accounts which, for example, fetishize transparency (see below) or which ally them to realist representation miss the point. Medical images are judged on their usefulness, and any objective correlative (such as, say, organising a data stream in the shape of a head) is there because it is useful.

Computed Tomography

Computed Tomography (CT scans) is another use of X-rays. They are one method of producing the familiar ‘slice’ type of medical image. In this case, a cathode ray emitter moves in a circle around the body, and opposite it at all times is a detector. Sometimes there are a number of detectors arranged as an array in a circle, but more usually one detector and the emitter move around opposite each other. A stream of electrons is emitted and the detector picks up how much of it gets through the body. Each complete rotation of the equipment produces a set of data that describes how dense the matter in the body is from each angle. More slices are made by moving the apparatus along slightly and repeating the rotation.

A computer runs an algorithm with this data to work out the possible pattern of densities for which this data would be a match. The results are shown graphically, with each density value given a specific colour or shading. The colours or shading that are used can be anything, but if very dense is shown as white and not dense is shown as black then a CT scan would look a bit like an X-ray ofa slice of a body. It is only by convention that the images made by CT scans are made to correspond in any way to traditional X-rays, to books on anatomy, or to actual slices of bodies that are made in autopsies (where the tissue slices are usually dyed to ‘unnatural’ colours anyway).

Already, we can begin to see from looking at how X-rays, DSA and CT are made that an ocularcentric account is not appropriate. Medical images are much closer to Latour’s notion of inscriptions than they are to ‘images’ in the photographic or cinematic sense. They are probably best understood to be data visualisations rather than as visual images.

Magnetic Resonance Imaging

Like CT, MRI scans produce ‘slice’ images. They are produced by passing electromagnetic waves of specific frequencies through the body in question. These waves are tuned so that they polarise the hydrogen atoms that are in the water contained in the body. Hydrogen has one proton which is in motion, so it acts like a tiny electromagnet. The magnetic wave resonates with the hydrogen-atommagnet and all the hydrogen-atom-magnets all become aligned (albeit some facing in opposite directions).

When the MRI wave is switched off, the hydrogen-atom-magnets settle back down again to their unaligned state. How long they take to do that depends on how soft the tissue is that they are in (i.e. soft tissue has more water in it than hard tissue).

The sensor arrays of MRI scanners can detect how long it takes for the hydrogen-atom-magnets at each point to settle down. As with CT scanners, the data that results is organised into a visualisation, but this time colours are attributed to different durations rather than different densities, with assumption being that the durations here are in any case functions of the tissue density.

With MRI, we are a long way from any conceivable ocularcentric visual metaphor. There is no eye, no lens, but instead a map of differential durations.

Functional MRI (fMRI) of the brain goes one stage further. Working on a chain of assumptions that brain functions are localised, that they are reflected in synaptic activity, that synaptic activity uses energy that must be replenished by glucose, and that blood flow will change quickly to deliver the extra glucose just as (or just before, or immediately after) it is required, and bearing in mind that blood contains a lot of water, a number of MRI scans are taken of a region of interest at regular intervals. Just as with DSA, the repeated information is removed, allowing just the changes to be visualised. The result is a map that purports to represent variations in intensity of brain activity rather than in bran density, but it can be understood as a graph of a map of liquidity.

We find ourselves in a realm of continuous variation, of relative degrees of softness and hardness, of flows, of differential liquidity. Actual organs are demarcated in two ways. One is that cell specialisation does mean that heart tissue is different from lung tissue is different from bone tissue and these differences are to do with the amount of water in them. The other is that the data that results from medical scanning techniques is augmented with information previously obtained from autopsies and anatomical reference books. The superposition of the cells’ own becoming-tissue as well as the dead upon the living is what territorialises these smooth data maps into striated organ spaces.

PET and SPECT

PET (Positron Emitter Tomography) is another ‘slice’ technology, only this time the slices are formed out the data concerning capture of positrons, and the positrons come out of the body because they were put there. PET is a nuclear imaging technology which requires patients to be injected with, or to ingest, radioactive substances that are then absorbed by the body. Different substances are absorbed by different parts of the body (the brain gets some, the liver gets others) so which radioactive substance is used depends on which organ the doctor is interested in. The radioactive isotypes have to have a half-life of about six hours so they can fit around the working day of a hospital without discharging radioactive patients into the streets, and so a whole secondary industry has been established for the manufacture and distribution of medical radioactive isotopes.

Like CT and PET, they are maps of intensity, but here the intensity stands for the degree of localisation and the extent of absorption. When the radioactive isotope is bound to glucose, it is possible to graph the movement of blood flow around the brain. MRI scans and other images are then used to organize the data – by which I mean to relate the information about location of activity that PET gives to the information about types of tissue that MRI gives.

CT, MRI and PET slices can all be assembled using a computer to create three-dimensional models. SPECT is a special variant of PET in that the protons are detected at many different angles, not all in the same plane, so that a 3D model of an organ can be computed with more continuous data.

Ultrasound

Ultrasound is yet another means to create graphs of tissue density. In this case the body space is rendered echoic, and a mini-sonar image is created. The map is a radial graph that shows the intensity of the returned sound (usually as a level of brightness) and the time it takes for a sound pulse to make the round trip from emitter to receiver (shown as distance from the device). More recent ultrasound technologies make use of computer to transform the radial co-ordinates into Cartesian ones, making the images look more ‘realistic’ to the untrained observer. It takes additional computational effort, therefore, to create visualisations that are closer to a sort of photographic ideal.

Additional Methods

The remaining category of medical imaging uses the heat emitted by bodies (thermograpy), the electrical conductivity of bodies (electrocardiography and electroencephalography5), and the naturally occurring magnetic fields (Megnetocardiography and Magnetoencephalography )around bodies to create maps of intensities .

2. Medical Images as Inscriptions

Lynch asserts, in relation to the referentiality of medical images, that a key function is as ‘communicative devices. . They have a material organization of their own, and are collectively discussed, reproduced and worked over’. (Lynch 2006, p. 28), whilst Pasveer states that ‘X-rays were ‘more objective’. They could be ‘examined in the absence of the patient, they could be carried around and studied by anyone interested and competent.’ (Pasveer 2006, p. 55)

Latour explains in Visualisation and Cognition that ‘scientists start seeing something once they stop looking at nature and look exclusively and obsessively at prints and flat inscriptions’ (Latour 1986, p. 15). He sets out nine advantages of what he terms inscriptions. These also serve to define them. Medical images exhibit a close fit with Latour’s attributes:

1. Medical Images are mobile. Certainly they are more mobile that the patients themselves, since the images can be disrtributed physically or electronically, even in real time, to garner the expertise and opinion of scientists wherever they are.
2. Medical images are also immutable when they move. Now that they are stored digitally, medical images can be shown in the same way to any number of people. Since the underlying data is also mobile and immutable, it is also possible for new perspectives on the same data to be created and shared.
3. Medical images are made flat. As Latour explains, ‘when someone is said to ‘master’ a question or to ‘dominate’ a subject, you should normally look for the flat surface that enables mastery (a map, a list, a census, the wall of a gallery, a card-index, a repertory); and you will find it’. Flat images are less confusing, and they facilitate informed discussion by ensuring that everyone is seeing the same data with nothing hidden. This need to make medical images less confusing than a fully representational image would be is an important aspect which is much overlooked in the cultural theory that currently surrounds medical images.
4. The scale of medical images can be modified at will. This is of huge advantage to medical practitioners who might want to zoom in on a part of a body at a level of detail that would not be possible in real life or, conversely, when a thermograph of an entire body is required.
1. They can be reproduced and spread at little cost. This is of crucial importance in establishing medical images as one of the de facto means by which disorders and pathologies are
2. described in medical literature and text books. Beyond their usefulness, this helps to explain their dominance in medical science.
5. ‘Since these inscriptions are mobile, flat, reproducible, still and of varying scales, they can be reshuffled and recombined’. This is of crucial importance both to the history of medical images and their current use. It was by being able to relate anatomical images to X-rays that X-rays began to prove their usefulness. Subtracting one image from another can be an extremely important technique. Slice images can be recombined to create 3D models. PET and MRI scans can be combined to show regions of the brain alongside activity in those regions.
6. It is possible to superimpose several images of totally different origins and scales. This is of great benefit, not least of all in surgical practice. Surgeons are able to see MRI, Flouroscopy and Endoscopy images superimposed on one another so that, for example, a laser can be guided to destroy a tumor. Although the body is itself at one scale, the different imaging technologies produce images at their own scales, so some rescaling and transformation is required to calibrate and coordinate them.
7. The can be made part of a written text. The destiny for some medical images is to become part of academic papers and text books, thus furthering the discourse of medicine and entrenching the use of medical images more deeply in medical practice.
8. The two-dimensional character of inscriptions can merge with geometry. In some senses medical images are formed out of calculus, but Latour is perfectly correct here. The ability to compare and measure surfaces and volumes is extremely important in, for example, the treatment of cancer, not merely in monitoring the development of tumors but in guiding the position of pulses of radioactivity in radiotherapy.

In proving capable of being described in terms of scientific inscriptions medical images become established as closer in nature to graphs and charts than photography or cinema.

3. Tropes of Hand and Eye in Computation

As is clear, computation plays an extremely important role in the production of medical images. Today even X-rays, which strictly speaking can be ‘traditionally’ produced without computers, make use of computer management of radiation doses, digital image processing and enhancement, and computer display technologies.

My claims concerning a prevailing ocularcentrism in how medical images have hitherto been analyzed might be countered with the observation that many images today are produced digitally and are therefore equally removed from any relation to eyes, cameras or any of the artisanal techne of representation.

However, there is an endemic, pervasive visuality in the metaphors concerning computer image creation and computer visualisation which indicates that digital images in general can be more fairly categorised as a special case among photography and cinema than can medical images, although of course that would still be reductive. Interactive Media Art has certainly been criticised for an overemphasis on the visual at the expense of other senses or forms of installation (Hansen 2003).

The metaphors that govern the Human Computer Interfaces of software programs such as Adobe Illustrator or Adobe Photoshop are replete with tools and icons that include brushes, pencils and hands. The images are formed of layers, conceptually stacked one above the other, giving a ‘topdown’ perspective to the user. Image layers are made visible or invisible (are ‘shown’ or ‘hidden’) using an ‘eye’ icon. Photoshop includes guides and transformations to assist in the production of images with linear perspective and to extend objects within a picture whilst taking account of a ‘point of view’ (such as extending the height of skyscraper, for example).

Tools that work with 3D such as After Effect or Blender directly evoke the concept of a camera. Camera symbols can be placed around a scene, their focal length and aperture individually adjusted, and each point of view can be ‘rendered’ as if seen through any of the cameras. Virtual light sources can also be placed around the scene and one method for making the images look more photorealistic is ‘ray tracing’ – modelling the specular effects of movement and multiple of reflections of light on the surfaces of the objects in the scene.

One might expect that Human Computer Interfaces would take as their paradigm the tools of earlier modes of image production – that’s how interface metaphors are often constructed – but even delving into programming languages, one finds that these too use Draw(), Line(), Camera(), Visible(), Color() in their graphics libraries (I’m referring here to C#, ActionScript, and Processing to name just a few).

At what is often termed even ‘lower’ levels of programming (and this spacialised metaphor of ‘high’ and ‘low’ levels might itself imply notions of visual perception) one finds everywhere the concepts of ‘reading’ and ‘writing’, so perhaps at this level we have at least a grammatological concept of computation.

Images that are made entirely with computers can fairly be said to be subject to these ocularcentric metaphors (in fact the same might be said of many of the metaphors that come with sound production in computers too – ocularcentrism tends to collapse all senses into sight). However,it remains a mistake to ignore the earlier processes that are involved in producing medical images such as the use of radioactivity and electromagnetism instead of light on the body in the production of data streams that are then manipulated and visualised using a computer.

4. Ocularcentrism in Cultural Analysis of Medical Images

Issues of resemblance, representation, reference, and indexicality are hotly contested within Science Studies and the philosophy of science. Some of the most famously adopted positions are neatly

summarised by Lynch:

Hanson’s (1967) discussion of theory-laden observation and Kuhn’s (1977) account of acquired similarity relations analyze observational activities in terms of individual perception and cognition. Polyani (1967) treats observational instruments as extensions of individual sense organs through which the skilled scientist learns to see or feel what the instrument discloses or contacts. Feyerbrand (1975) interprets visual representations as evidence of historically and culturally relative cognitive and perceptual processes. (Lynch 2006, p. 28)

At stake is how true medical images are in every possible metaphysical and aesthetic sense of true. A division is beginning to appear between how true these images are, and how useful they are.

In The Transparent Body: a Cultural Analysis of Medical Imaging, van Dijk speaks of a myth and anideal of transparency:

Mediated bodies are intricately interlinked with the ideal of transparency....In the area of medical imaging, inscription technologies such as X-ray, ultrasound, and endoscopy seek to dispose of mediation (such as artist’s drawing) and instead record the interior body directly onto a machine. The mechanical gaze into living bodies not only enhanced the body’s transparency, but also its manipulability. (van Dijck 2005, p. 15)

But surely the ideal of transparency to which van Dijck is that of the body, but of the media instead. A transparent body would be see-through, and what is at issue here is the becoming-visible of

bodies, of rendering through imaging technologies that which could not otherwise be seen (except at the cost of killing the patient, and even then that would reveal only structure, not processes).

Why should van Dijck conflate becoming more visible with becoming transparent? I venture to suggest that what she is describing is really better summarised by Levinas:

The phenomenology of images insists on their transparency. The intention of one who contemplates and image is said to go directly through the image, as though through a window, into the world it represents, and aims at an object. (Levinas, p. 121)

A transparent media would in this sense be the perfect media, since it would, without altering in any way, without drawing attention to itself as media, reproduce its object. It would be the perfect simulacrum of the object yet still refrain from collapsing in on the object itself. There would be an untraceable difference between the image and the object. By invoking transparency, van Dijck is also moving the discussion into being about ‘light’ rather than any other form of wave or particle. This trap seems especially hard to avoid, with Cartwright also saying at some point:

Light becomes a brutal force that physically penetrates its object, stripping away its concealing surface to lay its structure bare. (Cartwright 1995, p. 113)

Van Dijck and Cartwright are in danger of what Heidegger describes as reviving ‘the fortunately obsolete view that art is an imitation and depiction of reality’ (Heidegger, p. 88). Levinas suggests that resemblance is not the result of comparison of the ‘real’ with the ‘image’ but the ‘movement that engenders the image’? It is its movement through media, its mediation. The image also takes on its own reality as it becomes a form of media, since media itself cannot be considered to be outside of reality: ‘Reality would not be only what it is, what it is disclosed to be in truth, but it would also be its double; its shadow; its image.

What van Dijck really describes is, I think, her ideal of the ‘mechanical-medical’ eye gazing through media at a fully revealed body. The effect of the media is to cause the body to reveal more about itself. Unlike other forms of media which are assumed to somehow represent less than their object, medical images here appear to be imagined as revealing even more of the body than could be possible with direct interaction with the body itself. The media isn’t quite transparent in that it becomes super-revealing rather than absolutely neutral. The body is not transparent in that it becomes super-visible. What is implied in van Dijck’s (mis-)use of the term ‘transparent’ is the idea that medical images are somehow even more true than other forms of media, that by removing a surface they deliver a pure perception of a reality ‘out there’ (or maybe ‘in there’) that is presented without guile, pretence or dissimulation. But no media can be like that, and medical images in particular are not there primarily as aesthetic objects of representation, but as scientific inscriptions that are moving towards epistemology and action. Medical images require a ‘representational commitment’ which must have the correct intentional relationship to the subject matter’. (Mitchell 1992, p. 221). It is necessary to ‘’ overcome the idea that visual media have intrinsic representational qualities irrespective of their use and production context.” (Lynch 2006, p. 17).

Further, it is important to bear in mind that with medical images we are looking mainly at ‘proxies’ for the phenomenon which we assert we are ‘really’ looking for. This is extremely problematic, since it relies on a number of assumptions that one process or event can represent another even inside the body in question. Dumit cites one of his respondents as saying

The things we are measuring, it is not necessarily that glucose utilization is directly related at all to oxygen consumption, nor that these two parameters are directly related to electrical activity. And even if they were related,it is not necessarily true that electrical activity is related to the amount of information that is transmitted by neurons. It is not. If a neuron is firing more, it does not mean that it is transmitting more information, because in epilepsy, for example, the neurons are firing a huge amount. (Dumit 2003, p. 180)

A chain of substitution of proxies works as a chain of signifiers for what is purportedly the intention behind the creation of the image.

5. Diagnosis

Medical images are also, and perhaps more accurately, termed ‘diagnostic’ images. They straddle different forms of Kantian judgement. They are determinative in that an hypothesis is formed by the doctor in advance of making the image. The choice of which category of image is made is based on the doctor’s preliminary diagnosis, X-ray for fractures, MRI for cancer, etc. The doctor ‘goes looking’ for determinative evidence. Once formed, the diagnostic images become subject to reflexive judgement, with the entire medical discourse that brings this about being purposive/teleological. Their particular case is generalised into a plan for treatment, with the selection of appropriate treatments indicated by the, now specific, condition that has been identified. Diagnostic images are key moment in the transformation of thought into action. The case enters into the body of knowledge of medicine.

The image itself may undergo several iterations of having some kind of ‘title’. At first it may bear the title of the name of the person in question. If the organs depicted in the image have a body, it is the body of the patient. The image will circulate and be disseminated under the auspices of the case in question. Next the image may bear the title of a specific diagnosis, and it may begin to circulate under the auspices of being a specific example of a type of injury or pathology. Later, it may be considered exemplary of a diagnostic image (or of its failure as a diagnostic image) and find its way into a text books to become the general or ideal referent against which future ‘case’ images will be interpreted.

The word ‘diagnosis’ has an instructive etymology. ‘Gnosis’ tells us that we are within epistemology. Diagnosis is a form of knowledge. But ‘dia’ complicates the matter. ‘Dia’ suggests discernment, discrimination, knowledge across something or knowledge between things. Dia suggests that the gnosis, if it is thought to be singular, comes to us out of difference.

We have already encountered an intrinsic differential quality within the computed production of each medical image. Pixel values are given colours or shades depending on a sliding scale of some kind of intensity (radiological, electromagnetic, sonic, etc). All shading within an image is therefore relative.

The mathematics and scientific methods that underscore the production of medical images depends greatly on subtraction and differentiation. Different images are created by substracting one from another. ‘Noise’ in the image is almost always computationally eliminated, especially from outside the edge of the body. The values of each level of intensity is determined two-fold by Fast-Fourier-Transformations that are performed synchronously on data to determine intensity, and diachronously to determine location. (Fast-Fourier Transformations are a bit like graphic equalizers for spectra of data, allowing you to selectively exclude data that occur at a particular frequency or at particular times in a data stream.

Pasveer (2006) uses her analysis of the history of X-rays to show that diagnosis is predicated on the structural interplay of difference rather than straightforward reference. She challenges

An epistemology [which] is taken for granted [and] in which what is the case precedes the work of science (which ultimately is considered a work of unveiling). Is it assumed that images or other forms of knowledge claims represent what was already the case... Technologies of visualisation appear in such accounts as transparent, neutral intermediaries between nature and scientists... it seems impossible to go beyond this [idea of a] world ‘out there’ (Pasveer 2006)

This epistemology fails precisely in its willingness to take on what I would term the mediality of medical images:

. .. Accounts from within this epistemology thus always render invisible what is required before an image refers to anything in particular. They ignore the work of mediation in which an image comes to have a referent, and instead pretend that the scientific image delivers a clear and unmediated access to the referent out there. (Pasveer 2006, p. 43)

Medical images are always interpreted through comparison. When taking a chest X-ray, one lung is compared with the other, a patient’s X-ray taken at one time is compared with one taken at a different time, one patient’s X-ray is compared with a collection of other patients’ X-rays (Pasveer 2006, p. 55). The same is true for other categories of medical images. Pathology is determined by its difference from normality, and the norms are established through reference to other images of other patients.

Surely we can hope to envisage some pure, original, pre-mediated body that serves as the archetypal body against which all representations are judged? Not so, the body, explains Paveen, is ‘always already mediated’. There was indeed a first X-ray and a time before X-ray images, but their assimilation into medical practice was not predicated on their direct reference to bodies, but on the degree to which they could be made to fit with the history of anatomical representation up to that point:

There was no body ‘out there’ waiting to be unveiled with a new technology. There never was or will be. This body had to be crafted carefully out of historically specific other bodies, in order to become a referent for the images... This body was not a natural body outside of any medical frame whatsoever. It was always already a mediated body, a body of knowledge, a body within. (Pasveer 2006, pp. 44-49)

What was seen on X-rays had to be matched up through analysis of previous forms of medical imaging. What was heard through the stethoscope (Pasveer 2006, p. 51) had to find its correlative in the images formed with ‘new kind of ray’. The body that appears in medical images is a body made out of difference.

It is also an isolated body. The phenomenological tendency within medical imaging enframes the subject’s body in a black void, demarcated as a collection of organs without connection to the world outside itself. The force of this type of image proscribes a particular form of ontology, so that Dumit, for example is able to claim:

Brain imaging technologies like PET offer researchers the potential to ask a question about almost any aspect of human nature, human behaviour, or human kinds and design an experiment to look for the answer in the brain. (Dumit 2003, p. 15)

Can we say with certainty that ‘any aspect of human nature or human behaviour’ can be answered in the brain? Is there no scope for social dymanics, for situations and events, for non-biochemical forces, for genetics, for extreme circumstances, to determine human behaviour? It is here that medical science is at odds with social science and philosophers including Deleuze and Badiou.

Further, the medical images, like all case notes, become a kind of supplement to the patient. They are what designate the patient as a patient, and their condition and treatment as a case. The apparent referentiality of medical images means that even the patient can become complicit in this supplementary act. Patient and doctor alike can display the images in conference and, with apparent objectivity, understand the diagnosis and proposed course of action. The medical image becomes first supplement and then synecdoche for the case, whilst at the same time only being capable of having meaning through a form of difference without origin.

6. Medical Images and the Body without Organs

It may seem perverse to conclude a discussion of medical images with notion of the Body without Organs. Deleuze describes it as follows:

The body without organs is opposed less to organs that to that organization of organs we call an organism. It is an intense and intensive body. It is traversed by a wave that traces levels or thresholds in the body according to variations in amplitude. Thus the body does not have organs, but thresholds or levels. (Deleuze 2003, p. 44)

X-rays, MRI, CT, PET, Ultrasound are all apparatuses that regard the body as intense and intensive. They trace variations in radiation, in current, in magnetism, in sound. The body that is the subject of medical images becomes a body of thresholds and levels, which are only subsequently re-mapped as organs.

Media transform what they mediate. Under the regime of medical images, the body is in multiple states of becoming-liquid, becoming-nuclear, becoming-porous, becoming-electric, becoming-magnetic, becoming-emitter, becoming-echoic. Must we denigrate these bodily functions as somehow inadvertent, as incidental, as indicators? Can we not say instead that medical imaging brings forth new bodily functions? We do not need to argue here whether these bodily functions are ‘primary’ or ‘secondary’ as bodily functions are normally described. If I ever have lung cancer, my body’s capacity to become billions of tiny magnets is what might ensure my survival.

The true fault of ocularcentrism is to exclude this possibility. It attempts to reign in the possibility of new sensory organs, of new relations with the world, by acting as if medical images are an extension of an existing sense. They are not. Senses here are being added, not extended. A hitherto virtual aspect of the body is suddenly actualised.

Vibration, resonance and forced movement are the concepts Deleuze creates to describe the three types of syntheses that Bacon utilizes to ‘paint the sensation’. In general, these constitute the intensive conditions of sensation, the three ‘varieties’ of compositions of sensation, the three modalities of a ‘being of sensation’ (Smith 1996, p. 47)

Vibration (ultrasound), resonance (MRI) and forced movement (the fitting into the apparatus, the adopting specific positions) are the modalities of the figure within medical images. These affects that are normally associated with how images work flow back and are literalised in the body in question.

But these new senses are not intrinsic senses. They operate only in a techno-scientific assemblage that is outside the body. They operate in a multiplicity, with sensations that can only be understood differentially, requiring a norm that is stabilised statistically and by comparison with a larger population. What they are is a new form of sense that is not an extension of eye or hand. How they work is visually, but by differance rather than reference.

Is this, asks Deleuze, the definition of the percept itself – to make perceptible the imperceptible forces that populate the world, affect us, and make us become? (Deleuze & Guattari 1994, p. 181)

7. Notes

¹ Sawday 1996, van Dijck 2005, Cartwright 1995, Dumit 2003, Ihde 2001, Pasveer 2006

² A future chapter will examine the role that brain imaging plays in the diagnosis of ‘contested’ disorders such as schizophrenia

³ In defense of ocularcentrism, there is one additional medical imaging technology that uses cameras: endoscopy.

⁴ (Wolbarst 1999). The descriptions in this section are largely based on Wolbarst, but have been written in such a way as to emphasise the most relevant specificities of each media. Detailed algorithms have been omitted here, although future practical work is likely to make creative use of medical imaging algorithms.

⁵ As you might expect, ‘-cardio’ relates to the heart, ‘-encephalo’ relates to the brain.

8. Bibliography

1995, Embodiment And Experience: the Existential Ground of Culture And Self (Cambridge Studies in Medical Anthropology), Cambridge University Press, Cambridge University Press.

1995, Resisting the Virtual Life, City Lights, City Lights.

2000, Art And the Brain, Ii: Investigations Into the Science of Art (Journal of Consciousness Studies: Controversies in Science & the Humanities), Imprint Academic, Imprint Academic.

2003, The Self in Neuroscience And Psychiatry, Cambridge University Press, Cambridge University Press.

2004, Schizophrenia: From Neuroimaging To Neuroscience, OUP Oxford, OUP Oxford.

2005, Medical Image Computing And Computer-Assisted Intervention -Miccai 2005: 8th International Conference, Palm Springs, Ca, Usa, October 26-29, 2005, Proceedings,. / Lecture Notes In Artificial Intelligence), Springer, Springer.

2006, Development of Physics Applied To Medicine in the Uk, 1945-1990, Wellcome Trust Centre for the History of Medicine, Wellcome Trust Centre for the History of Medicine.

2007, Mediaarthistories (Leonardo Books), The MIT Press, The MIT Press.

Ansell-Pearson, K & Pearson, KA 2001, Philosophy And the Adventure of the Virtual, Routledge, Routledge.

Antonelli, P 2008, Design And the Elastic Mind, Museum of Modern Art, Museum of Modern Art.

Ars, E 2001, Ars Electronica: Facing the Future: a Survey of Two Decades (Electronic Culture: History, Theory, And Practice), The MIT Press, The MIT Press.

Asselin, O 2008, Precarious Visualities: New Perspectives on Identification in Contemporary Art And Visual Culture, McGill-Queen's University Press, McGill-Queen's University Press.

Badiou, A 1999, Deleuze: the Clamor of Being, University of Minnesota Press, University of Minnesota Press.

Badiou, A 2007, The Concept of Model: An Introduction To the Materialist Epistemology of Mathematics (Transmission), Re.Press, Re.Press.

Banerjee, A 1993, The Radiology of Aids (Clinical Film Viewing), Clinical Press Ltd, Clinical Press Ltd.

Barrow, JD 2008, Cosmic Imagery: Key Images in the History of Science, Bodley Head, Bodley Head.

Baudrillard, J 2000, 'The Evil Demon of Images', in C Cazeaux (ed.), The Continental Aesthetics Reader, 1st edn, Routledge, London.

Benjamin, A & Osbourne, P 1991, Thinking Art: Beyond Traditional Aesthetics, Ica, Ica.

Bergson, H 1991, Matter And Memory, Zone Books,U.S., Zone Books,U.S.

Bhaskar, R 2008, A Realist Theory of Science (Radical Thinkers), Verso, Verso.

Blackshaw, G, Topp, L, Imrie, N, Heighton, L, Wieber, S & Howes, GC 2009, Madness And Modernity: Mental Illness And the Visual Arts in Vienna 1900, Lund Humphries, Lund Humphries.

Boyle, M 2002, Schizophrenia: a Scientific Delusion-, Routledge, Routledge.

Bradley, WG 1985, Magnetic Resonance Imaging of the Brain, Head And Neck: a Text-Atlas, Lippincott Williams and Wilkins, Lippincott Williams and Wilkins.

Bruscky, P 2006, Paulo Bruscky, Companhia Editora de Pernambuco, Companhia Editora de Pernambuco.

Carter, R & Frith, CD 2000, Mapping the Mind, Phoenix, Phoenix.

Cartwright, L 1995, Screening the Body: Tracing Medicine's Visual Culture, University of Minnesota Press, University of Minnesota Press.

Caufield, C 1989, Multiple Exposures: Chronicles Of The Radiation Age, Secker & Warburg, Secker & Warburg.

Cohen, J 1998, Spectacular Allegories: Postmodern American Writing And The Politics Of Seeing, PLUTO PRESS, PLUTO PRESS.

Collective, TMT 1994, Rethinking Technologies, University of Minnesota Press, University of Minnesota Press.

Connor, S 2003, The Book of Skin, Reaktion Books, Reaktion Books.

Damasio, AR 2000, The Feeling of What Happens, Vintage, Vintage.

Damasio, AR 2004, Looking for Spinoza, Vintage, Vintage.

Darley, A 2000, Visual Digital Culture: Surface Play And Spectacle in New Media Genres (Sussex Studies in Culture And Communication), Routledge, Routledge.

DeLanda, M 2002, Intensive Science And Virtual Philosophy (Transversals: New Directions in Philosophy), Continuum International Publishing Group -Mansell, Continuum International Publishing Group -Mansell.

Deleuze, G 1989, Cinema: the Time-Image V. 2 (Athlone Contemporary European Thinkers), Continuum International Publishing Group -Athlone, Continuum International Publishing Group -Athlone.

Deleuze, G 1990, Bergsonism, Zone Books, Zone Books.

Deleuze, G 1997, Essays Critical And Clinical, University of Minnesota Press, University of Minnesota Press.

Deleuze, G 2001, Cinema 1: the Movement Image (Athlone Contemporary European Thinkers (Paperback)), Continuum International Publishing Group -Mansell, Continuum International Publishing Group -Mansell.

Deleuze, G 2003, Desert Islands And Other Texts (1953-1974) (Semiotext(E) / Foreign Agents), Semiotext(e), Semiotext(e).

Deleuze, G 2003, Francis Bacon: the Logic of Sensation (Athlone Contemporary European Thinkers), Continuum International Publishing Group -Mansell, Continuum International Publishing Group -Mansell.

Deleuze, G 2006, The Fold (Continuum Impacts), Continuum International Publishing Group Ltd., Continuum International Publishing Group Ltd.

Deleuze, G 2006, Two Regimes of Madness: Texts And Interviews 1975-1995 (Semiotext(E) / Foreign Agents), Semiotext(e), Semiotext(e).

Deleuze, G & Guattari, F 1994, What is Philosophy, Verso, London.

DELEUZE, G & Guattari, F 2001, A Thousand Plateaus, Continuum International Publishing Group -Mansell, Continuum International Publishing Group -Mansell.

Deleuze, G & Guattari, F 2003, Anti-Oedipus: Capitalism And Schizophrenia (Athlone Contemporary European Thinkers (Paperback)), Continuum International Publishing Group -Mansell, Continuum International Publishing Group -Mansell.

Deleuze, G & Parnet, C 2002, Dialogues (Athlone Contemporary European Thinkers), Continuum International Publishing Group Ltd., Continuum International Publishing Group Ltd.

Denis, M 2005, Neuroimaging of Mental Imagery: Special Issue of the European Journal of Cognitive Psychology (V. 16, No. 5), Psychology Press, Psychology Press.

Derrida 1987, The Truth in Painting, Chicago University Press, Chicago University Press.

Derrida, J 2000, 'The Parergon', in C Cazeaux (ed.), The Continental Aesthetics Reader, 1st edn, Routledge, London.

Dixon, S 2007, Digital Performance: a History of New Media in Theater, Dance, Performance Art, And Installation (Leonardo Books), The MIT Press, The MIT Press.

Dodds, G 2005, Body And Building: Essays on the Changing Relation of Body And Architecture, The MIT Press, The MIT Press.

Dumit, J 2003, Picturing Personhood: Brain Scans And Biomedical Identity, Princeton University Press, Princeton University Press.

Dunleavy, P 2003, Authoring a Phd Thesis: How To Plan, Draft, Write And Finish a Doctoral Dissertation, Palgrave Macmillan, Palgrave Macmillan.

Durand, R & Heartney, E 2004, Orlan: Carnal Art, Flammarion, Flammarion.

Eisenberg, RL 1987, Diagnostic Imaging: An Algorithmic Approach, Lippincott Williams and Wilkins, Lippincott Williams and Wilkins.

FAIA, RB 2006, The Architecture of Medical Imaging: Designing Healthcare Facilities for Advanced Radiological Diagnostic And Therapeutic Techniques, John Wiley & Sons, John Wiley & Sons.

Flusser, V 1999, The Shape of Things, Reaktion Books, Reaktion Books.

Flusser, V 2000, Towards a Philosophy of Photography, Reaktion Books, Reaktion Books.

Flusser, V 2002, Writings (Electronic Mediations), University of Minnesota Press, University of Minnesota Press.

Foucault, M 1971, Madness And Civilization: a History of Insanity in the Age of Reason, Routledge, Routledge.

Foucault, M 1990, Archaeology of Knowledge, Routledge, Routledge.

Foucault, M 1990, The History of Sexuality: the Care of the Self V. 3 (Penguin History), Penguin Books Ltd, Penguin Books Ltd.

Foucault, M 1992, The History of Sexuality: the Use of Pleasure V. 2 (Penguin History), Penguin Books Ltd, Penguin Books Ltd.

Foucault, M 1998, The History of Sexuality, Penguin Books Ltd, Penguin Books Ltd.

Foucault, M 2003, The Birth of the Clinic (Routledge Classics), Routledge, Routledge.

Fuller, M 2005, Media Ecologies: Materialist Energies in Art Technoculture (Leonardo Book), MIT Press, MIT Press.

Gilman, SL 1996, Seeing the Insane, University of Nebraska Press, University of Nebraska Press.

Grau, O 2004, Virtual Art: From Illusion To Immersion (Leonardo Books), The MIT Press, The MIT Press.

Greenfield, S 2004, Inside the Body (Photographic), Cassell Illustrated, Cassell Illustrated.

Greenfield, S & Whitfield, P 1997, How We Work, Marshall Editions, Marshall Editions.

Grice, ML 2001, Experimental Cinema in the Digital Age (Bfi Film Classics (Paperback)), BFI Publishing, BFI Publishing.

Guattari, F 1995, Chaosmosis: An Ethicoaesthetic Paradigm, Indiana University Press, Indiana University Press.

Guattari, F 1995, Chaosophy (Semiotext(E) / Foreign Agents), Semiotext[e], Semiotext[e].

Hacking, I 1990, The Taming of Chance (Ideas in Context), Cambridge University Press, Cambridge University Press.

Hacking, I 2000, The Social Construction of What-, Harvard University Press, Harvard University Press.

Hansen, MBN 2003, New Philosophy for a New Media, 1st edn, The MIT Press, Cambridge, Massachusetts.

Haraway, DJ 1996, Simians, Cyborgs And Women: the Reinvention of Nature, Free Association Books, Free Association Books.

Hayles, NK 1999, How We Became Posthuman: Virtual Bodies in Cybernetics, Literature, And Informatics, University of Chicago Press, University of Chicago Press.

Heidegger, M 2000, 'The Origin of the Work of Art', in C Cazeaux (ed.), The Continental Aesthetics Reader, 1st edn, Routledge, London.

Ihde, D 2001, Bodies in Technology (Electronic Mediations, V. 5), University of Minnesota Press, University of Minnesota Press.

Jacques Derrida 1977, Of Grammatology, Johns Hopkins University Press, Johns Hopkins University Press.

Jacques Derrida 1998, Archive Fever: a Freudian Impression (Religion And Postmodernism Series), University of Chicago Press, University of Chicago Press.

James, G 2002, The Body Electric An Anatomy of the New Bionic Senses, Weidenfeld & Nicolson, Weidenfeld & Nicolson.

Johnston, E 2004, Companion To Psychiatric Studies (Mrcpsy Study Guides), Churchill Livingstone, Churchill Livingstone.

Jones, C 2006, Sensorium: Embodied Experience, Technology, And Contemporary Art, The MIT Press, The MIT Press.

Jung, C 1995, Memories, Dreams, Reflections (Flamingo), Fontana Press, Fontana Press.

Keller, E 2003, Making Sense of Life: Explaining Biological Development with Models, Metaphors, And Machines, Harvard University Press, Harvard University Press.

Kellner, D 1995, Media Culture: Cultural Studies, Identity And Politics Between the Modern And the Postmodern, Routledge, Routledge.

Kemp, M & Wallace, M 2000, Spectacular Bodies: the Art And Science of the Human Body From Leonardo To Now, University of California Press, University of California Press.

Kevles, BH 1996, Naked To the Bone: Medical Imaging in the Twentieth Century (Sloan Technology), Rutgers University Press, Rutgers University Press.

Kittler, FAEAIBJ 1997, Literature, Media, Information Systems (Critical Voices In Art, Theory & Culture), Routledge, Routledge.

Kittler, FA 1999, Gramophone, Film, Typewriter (Writing Science), Stanford University Press, Stanford University Press.

Komesaroff, PA 1995, Troubled Bodies: Critical Perspectives on Postmodernism, Medical Ethics, And the Body, Duke University Press, Duke University Press.

Kuhn, TS 1970, The Structure of Scientific Revolutions (Foundations of Unity of Science), University of Chicago Press, University of Chicago Press.

Kuppers, P 2007, The Scar of Visibility: Medical Performances And Contemporary Art, Univ Of Minnesota Press, Univ Of Minnesota Press.

Lacan, J 1993, Seminar of Jacques Lacan: the Psychoses, 1955-56 Bk.3, Routledge, Routledge.

Laqueur, T 1992, Making Sex: Body And Gender From the Greeks To Freud, Harvard University Press, Harvard University Press.

Latour, B 1986, 21-DRAWING-THINGS-TOGETHER.PDF, viewed 3 March 2009, <http://www.bruno-latour.fr/articles/article/21-DRAWING-THINGS-TOGETHER.pdf>.

Levinas, E 2000, 'Reality and its Shadow', in C Cazeaux (ed.), The Continental Aesthetics Reader, First Edition edn, Routledge, London.

Littleton 1983, Sectional Imaging Methods Cb, Lippincott Williams and Wilkins, Lippincott Williams and Wilkins.

Lynch, M 2006, 'The Production of Scientific Images: Vision and Re-Vision in the History, Philosophy, and Sociology of Science', in L Pauwels (ed.), Visual Cultures of Science: Rethinking Representational Practices in Knowledge Building And Science Communication, 1st edn, Dartmouth College, Lebanon.

Lyotard, J-F1-1984, The Postmodern Condition: a Report on Knowledge (Theory & History of Literature), Manchester University Press, Manchester University Press.

Maisey, MN, Wahl, RL & Barrington, SF 1999, Atlas of Clinical Positron Emission Tomography,A Hodder Arnold Publication, A Hodder Arnold Publication.

Massumi, B 1992, A User's Guide To Capitalism And Schizophrenia: Deviations From Deleuze And Guattari, The MIT Press, The MIT Press.

Massumi, B 2002, Parables for the Virtual: Movement, Affect, Sensation (Post-Contemporary Interventions / Latin America in Translation), Duke University Press, Duke University Press.

Mitchell, WJ 1992, The Reconfigured Eye: Visual Truth in the Post-photographic Era, 1st edn, MIT Press, Cambridge.

Morison, A 1976, The Physiognomy Of Mental Diseases (Classics In Psychiatry), Arno Press, Arno Press.

Nancy, J-L 1994, The Birth To Presence (Meridian: Crossing Aesthetics), Stanford University Press, Stanford University Press.

Nancy, J-L 2008, The Sense of the World, Univ Of Minnesota Press, Univ Of Minnesota Press.

Nelkin, D & Tancredi, LR 1991, Dangerous Diagnostics: Social Power Of Biological Information, Basic Books, Basic Books.

Neumann 2000, The Computer And the Brain (Yale Nota Bene), Yale University Press, Yale University Press.

Nietzsche, F 2000, 'On Truth and Lie in an Extra-Moral Sense', in C Cazeaux (ed.), The Continental Aesthetics Reader, 1st edn, Routledge, London.

Ninacs, A-M 2002, Massimo Guerrera: darboral : ici, maintenant, avec l'impermanence de nos restes, Musee de Quebec, Quebec, Canada.

O'Mahony, M 2002, Cyborg: the Man-Machine, Thames & Hudson, Thames & Hudson.

O'Sullivan, S 2006, Art Encounters Deleuze And Guattari: Thought Beyond Representation (Renewing Philosophy), Palgrave Macmillan, Palgrave Macmillan.

Pasveer, B 2006, 'Representing or Mediating: A History and Philosophy of X-ray Images in Medicine', in L Pauwels (ed.), Visual Cultures of Science: Rethinking Representational Practices in Knowledge Building And Science Communication, 1st edn, Dartmouth College, Lebanon.

Paul, C 2003, Digital Art (World of Art), Thames & Hudson Ltd, Thames & Hudson Ltd.

Pauwels, L 2006, 'A Theoretical Framework for Assessing Visual Representational Practices in Knowledge Building and Science Communications', in L Pauwels (ed.), Visual Cultures of Science: Rethinking Representational Practices in Knowledge Building And Science Communication, 1st edn, Dartmouth College, Lebanon.

Pierce, JR 1981, An Introduction To Information Theory, Symbols, Signals And Noise, Dover Publications Inc., Dover Publications Inc.

Plessis, ED 2005, The Advertised Mind: Ground-Breaking Insights Into How Our Brains Respond To Advertising, Kogan Page, Kogan Page.

Popper, F 2007, From Technological To Virtual Art (Leonardo Books), The MIT Press, The MIT Press.

Ramachandran, V, Humphrey, N & Harth, E 1999, Art And the Brain: 6 (Journal of Consciousness Studies), Imprint Academic, Imprint Academic.

Ranciere, J 2007, The Future of the Image, Verso, Verso.

Richardson, R 2008, The Making of Mr Gray's "Anatomy": Bodies, Books, Fortune And Fame, OUP Oxford, OUP Oxford.

Roszak, T 1994, The Cult of Information: a Neo-Luddite Treatise on High-Tech, Artificial Intelligence, And the True Art of Thinking, University of California Press, University of California Press.

Sawday, J 1996, The Body Emblazoned: Dissection And the Human Body in Renaissance Culture, Routledge, Routledge.

Serres, M 1995, Conversations on Science, Culture, And Time: Michel Serres with Bruno Latour (Studies in Literature And Science), University of Michigan Press, University of Michigan Press.

Serres, M 1997, Genesis (Studies in Literature And Science), University of Michigan Press, University of Michigan Press.

Shannon, CE & Weaver, W 1949, The Mathematical Theory of Communication, University of Illinois Press, University of Illinois Press.

Sharma, T 2001, Brain Imaging in Schizophrenia: Insights And Applications, Remedica Publishing, Remedica Publishing.

Shaw, J 2003, Future Cinema: the Cinematic Imaginary After Film (Electronic Culture: History, Theory, And Practice), The MIT Press, The MIT Press.

Smith, DW 1996, 'Deleuze's Theory of Sensation: Overcoming the Kantian Duality', in P Patton (ed.), Deleuze: a Critical Reader, 1st edn, Wiley-Blackwell, Oxford.

Sole, RV 2002, Signs of Life: How Complexity Pervades Biology, HarperCollins Publishers, HarperCollins Publishers.

Sontag, S 2004, Regarding the Pain of Others, Penguin Books Ltd, Penguin Books Ltd.

Steiner, RE 1984, Nuclear Magnetic Resonance And Its Clinical Applications (British Medical Bulletin), Churchill Livingstone, Churchill Livingstone.

Stengers, I 1997, Power And Invention: Situating Science (Theory Out of Bounds Series , Vo 10), University of Minnesota Press, University of Minnesota Press.

Stengers, I 2000, The Invention of Modern Science (Theory Out of Bounds), University of Minnesota Press, University of Minnesota Press.

Stiegler, B, Beardsworth, R & Collins, G 1998, Technics And Time: the Fault of Epimetheus No. 1 (Meridian: Crossing Aesthetics), Stanford University Press, Stanford University Press.

Stone, MH 1998, Healing the Mind: History of Psychiatry From Antiquity To the Present, Pimlico, Pimlico.

Thacker, E 2004, Biomedia (Electronic Mediations), University of Minnesota Press, University of Minnesota Press.

Tufte, ER 1990, Envisioning Information, Graphics Press, Graphics Press.

Tufte, ER 1997, Visual Explanations: Images And Quantities, Evidence And Narrative, Graphics Press, Graphics Press.

Tufte, ER 2001, The Visual Display of Quantitative Information, Graphics Press USA, Graphics Press USA.

Tufte, ER 2006, Beautiful Evidence, Graphics Pr, Graphics Pr.

Tumber, H 2000, Media Power, Professionals And Policies, Routledge, Routledge.

van Dijck, J 2005, The Transparent Body: a Cultural Analysis of Medical Imaging, University of Washington Press, University of Washington Press.

Virilio, P 1989, War And Cinema: Logistics of Perception, Verso Books, Verso Books.

Virilio, P 1994, The Vision Machine (Perspectives), Indiana University Press, Indiana University Press.

Virilio, P 2005, The Information Bomb (Radical Thinkers), Verso Books, Verso Books.

Virilio, P 2007, Speed And Politics (Semiotext(E) / Foreign Agents), Semiotext(e), Semiotext(e).

Wegenstein, B 2006, Getting Under the Skin: Body And Media Theory, MIT Press, MIT Press.

Weizenbaum, J 1993, Computer Power And Human Reason (Penguin Science), Penguin Books Ltd, Penguin Books Ltd.

Wiener, N 1988, The Human Use of Human Beings: Cybernetics And Society (Da Capo Paperback), Da Capo Press, Da Capo Press.

Wolbarst, A 1999, Looking Within: How X-Ray, Ct, Mri, Ultrasound And Other Medical Images Are Created And How They Help Physicians Save Lives: How X-Ray, Ct, Mri, Ultrasound. And How They Help Physicians Save Lives, University of California Press, University of California Press.

Woolgar, S 1988, Science: The Very Idea, Tavistock, London.

Zielinski, S 2006, Deep Time of the Media: Toward An Archaeology of Hearing And Seeing By Technical Means (Electronic Culture: History, Theory, And Practice), The MIT Press, The MIT Press.

Zielinski, S 2007, Audiovisions: Cinema And Television As Entr\'actes in History (Film & Culture in Transition), Amsterdam University Press, Amsterdam University Press.