Why our bodies *should* end at the skin. And a few reasons they maybe don't have to.

One thing that writing the last post on Margrit Shildrick's Rethinking Prostheses talk has done is to get me thinking about that key question posed by Donna Haraway: "Why should our bodies end at the skin?". Or rather, it's got me thinking about it in more detail. I mentioned that this question in particular intrigued me in the context of the Human Computer Cyborg concept: I've always found it interesting the extent to which we engage with and utilise technology and our environment. However, this is very much a "systems perspective" - me thinking as an engineer. The notion that systems couple and uncouple to form new supersystems and subsystems is pretty inherent to the engineering mindset (more on this if I ever get round to reviewing Guru Madhaven's excellent "Think Like an Engineer" which is my current reading). One thing that did crop into my head though was the whole issue of the skin as a boundary, both physically and intentionally. These are thoughts in progress - I'm basically just throwing down what comes into my mind. Thinking out loud - or, er, thinking out visibly, at any rate.

Biology and Me
So, another caveat: I'm not a biologist. I dropped biology after doing GCSE dual-award science. I like physics and mathematics and mechanics: I like force diagrams, equilibria, calculus, equations of motion. I like the fact that a few fundamental principles build systematically on each other so that we can predict and model the behaviour of complex systems (with greater or lesser accuracy). Biology on the other hand (as I experienced it - maybe it's different as you go higher up) is all classifications and systems, and a soup of stuff that don't really tie logically together in my mind. I can't really explain it. You can ask my wife: she's a consultant geriatrician and the polar opposite of me in this respect. She likes classifications and symptoms and body systems and diagrams of organs, and really struggles with physics. It's like a whole different way of thinking: which may explain why she's a doctor and I'm an engineer, of course. I like biomechanics, though. That makes sense to me. A skeleton as a set of rigid body elements connected by actuated joints? Movement modelled using control theory? This I like. But I don't know much about the skin, so I may be completely wrong about all this. Feel free to let me know.

Unfortunately, the skin doesn't really feature in this reading. I've never done a model or a calculation where the skin was anything but a friction coefficient, with the annoying characteristic of being difficult to predict accurately (you might like to talk to my colleague Brian Henson who's done rather a lot on this!). So, in my engineering mindset, it's not difficult to conceive of a bit of extra mass or a longer rigid body, or of swapping bone for metal in hip replacements. There are huge practical issues to this integration, of course - but as a concept it's one that's easy for me to grasp. That makes the skin an interesting boundary.

The Five (plus) Senses
I was thinking about all this in the context of proprioception (the sense of where our body parts are relative to each other, even when we can't see them) as I was drawing up a control model for prehensile movements. Proprioception isn't tied in with the skin as far as I know - but it is contained within it. I mean, we have no proprioception for our hair, for example. That matters little to me these days, but in the days when I had hair reaching my waist, it wasn't too difficult to inadvertently lie down and trap it under it my shoulders because I didn't know that the sweeping it aside with my hand hadn't worked. Indeed, of the multitude of senses available, many (sensing temperature, vibrations, tasting, sense of balance, pain) rely on something interacting with or bypassing our skin. Even sight and sound rely on electromagnetic or airwaves being projected into our bodies. If I close my eyelids, no sight: if sound doesn't reach my ear drum, then I don't hear it. That's a very, very simplistic reading, of course, but it gives the jist. I don't have any external senses - the skin represents the limit of my ability to sense the world around me. It also represents the locus of my central nervous system's control. My skin represents the space envelope that I can project around me: I can adjust its shape and size and position by activating muscles and reorienting my skeleton, but if I want to exert forces on the world around me, they have to come through my skin. Again, this is very simplistic - biting, for example, would be a counter example. But for the most part, the skin is a good analogy for the physical boundary of the space I occupy, so it's not too surprising if we take it as the limit of a body.

Inner Space
A knee or hip replacement represents a clear crossing of the skin as a boundary, but doesn't change its nature. It swaps bone for metal, polymer and plastic. It seems reasonable to assume that these are subsumed into the person: though whether recipients feel that way is a different matter. The implant is clearly within the body, unlike an externally attached prosthetic: it's removal and replacement is nontrivial. Getting through the skin is a major event.

This raises another significant factor - namely the problem of piercing the skin. The skin is our first layer of defence - once broken, the way is open to many infections: a risk to any operation. Also, within the body, any outside material can be subject to rejection. The immune system can take exception: implanted sensors become fouled and damaged. It's not impossible to circumvent this, but the reality is that changes under the skin present a different challenge to those outside. Again, the skin represents a clear delineation between internal and external environments.

Body Modification
Another objection might be the issue of body modification: Tattoos and piercings. Not, I suppose, cosmetic surgery, since this might be taken to change the skin, rather than the inner or outer environments; implants are I suppose covered by the discussion above.

I know little of body modification, having no tattoos or piercings, and never feeling any desire for them, so my scope for discussion is limited and I could be way off the mark. I suppose, though, that piercings rely on reshaping the skin; tattoos might come under implants, though they are a little different in the sense of residing in the skin rather than under it. Thus, the skin marks a natural, clearly defined, objective, physical system boundary for defining the limits of the body and person. What objections could there be?

Hair, Nails and Whiskers
Of course, the hair and nails are body parts that reside outside the skin. We cut both off in a way we would not other parts of our body: they have no sensation, and we don't control them directly. But we would,  I think, instinctively recognise them as part of the body. If someone shaved your head, or cut off your ponytail,  would this be seen as the same as ripping someone's shirt?  Or something more personal? Whiskers are another interesting example - outside the body, but used for sensing.

Disassembly
Perhaps the most compelling argument for the skin defining our bodies is related to the issue of assembly (or assemblage, as discussed by Margrit Shildric - see my post on her talk). Fundamentally: disassembling anything within our skin causes injury.
    From a systems perspective, the skin delimits a system that is difficult to subdivide. I can remove my clothes and put on other clothes; I can pick up different tools; climb into or out of a car, with much less effort and risk than I could remove my arm, or my kidneys. There's a pretty clear difference there. Even disassembling a tattoo from the body is painful and time-consuming.  Compare that with a transfer which stays firmly outside the skin.
   A recent tweet from Open Bionics really brought this home to me. It concerns the recipient of the first hand transplant (or hands transplant, since both hands were replaced), who now wants them removed. This raises two interesting issues: first, it again raises the equivalence between transplants and prostheses as ways to replace or augment body parts. Secondly, it highlights the issue of the skin as a boundary: once grafted on, the hands are difficult and risky to remove in a way that prosthetic  hands are not. The same holds for a heart bypass, a pacemaker, an artificial hip. Once inside the skin, these things are very difficult to remove.

In summary, then: there are several good reasons to take the body as ending at the skin:

1. The skin represents the boundary of one's senses and actions. We can't sense anything that doesn't have some way of reaching the space envelope of the skin (including reflected light and sound - after all, eyes and ears are within this space) and we can't anything except through the intermediary of the skin (sound and breath being exceptions, but these originate within rather than without the envelope defined by the skin). Even a tool or instrumented which permits remote sensing or action then has to communicate to the body.

2. Removing things once they are within the skin is inherently more difficult than things without. The skin as a system boundary encompasses a system that is difficult to subdivide. Systems external to the skin are easier to assemble and disassemble with than those within the skin.

3. That very difficulty renders it more objective - it provides a physical definition of the space a person occupies, and a physical system boundary. You don't need to argue about which bits are in you and which are in someone else.

So it's pretty clear that our bodies end at the skin. Or is it?

Queering the Deal
There are a few interesting counterexamples. Of course, you can probably get into questions about what defines a body as opposed to what defines a person. I'm sure smarter minds than mine have grappled with exactly this, so bear with me if this is very basic.

Firstly: robotic prosthetics are a very interesting case. Take a look at Open Bionics' Ada hand (or any of their jazzy variants, for that matter!).  It has sensors and actuators, and intelligence.  It uses EMG to control it - reading signals sent to the muscles by the CNS. Admittedly, it doesn't feed back to the CNS, and it reads across the skin, but still. Colleagues at the University are working on stimulating nerve endings using vibrations to produce sensations for remote touch. Again, without breaking the skin, but still - once these are being controlled directly by the CNS, the boundary with the body blurs. A lot.

Secondly, there is a practical consideration.  I was struck by Sir Bert Massie CBE's post about the AT Hub, discussing the perils of compartmentalising AT. If you take the skin as the limit of the person, you miss the fact that many such devices aren't optional extras, but essential to their wellbeing, and if they are removed, damaged, or rendered unusable by circumstances, the consequences are just as disabling as losing part of the body. I'm talking out of turn there: making inferences from what I read, and about which I have little meaningful experience. And it almost certainly wasn't Sir Bert's intention to raise issues about the definition of the body, rather about the importance of communication and integration between stakeholders in AT and hence the need for the AT Hub.  

But it's an interesting issue, and important to the conception of the body and the self. In summary - there are some pretty good reasons to take the skin as a special boundary and as defining the limits of the body. But there are some practical reasons to extend that concept, and new technologies that rather blur the boundaries.

Anyway - these are just my musings: thinking out loud. Feel free to let me know your thoughts.

Margrit Shildrick: Rethinking Prostheses

It's been a little while since Margrit Shildrick gave her talk at Leeds Uni, titled "Rethinking Prostheses: Technologies, Boundaries and Embodiment", and this post has been slowly cobbled together in spare moments since then, but I think it ties nicely with the "Engineering Imagination" concept and is well worth getting down my thoughts on.

Caveat Lector

I'll put one significant caveat on the front of this: this presentation was way out of my discipline, and I'm not sure I have a good grasp of all the concepts involved. I had originally planned to go and read up on some of the issues: I still do, but thought it would be far better to get my gut reaction down. Examples of the phrases that I don't think mean what I think they mean are marxist (which to me means communist/socialist), feminist (which to me means women's rights and perspectives), embodiment (which to me is the way an idea takes physical form - such as moving from concept to embodiment design), and unproblematized (no idea what this means: based on the context I infer that something like "someone hasn't thought through the problems with this"). I don't say this to mock: just to highlight that jargon is an issue in cross-disciplinary work, and I may well have the wrong end of the stick. The point is that what I'm about to write is based on a lay perspective, so bear with me.

An engineer at a talk from Gender and Knowledge Production?

Margrit Shildrick is Professor of Gender and Knowledge Production at Linkoping University in Sweden. To date, I've had no exposure to her work except what I saw at her talk, so I'm coming to it fresh (read: naïve). However, with a title like "Rethinking Prostheses", it would seem odd for any engineer interested in prosthetics and AT not to go. My particular interest, however, lay in a question mentioned in the talk's advert: "Why should our bodies end at the skin?".

It turns out that this question was posed by Donna Haraway, another writer whom I had never come across (this will be a running theme - another common feature of multidisciplinarity - so let's just assume that unless I say otherwise, I'm not familiar with any of the work Shildrick mentioned). Wikipedia informs me that Haraway is "a Distinguished Professor Emerita in the History of Consciousness Department and Feminist Studies Department at the University of California, Santa Cruz", and author of "The Cyborg Manifesto".

I first became interested in the notion of the boundaries of where a person ends and the integration of technology into our selves (not necessarily into our bodies!) when in the early stage of my career a noted Professor mentioned in a conversation about Farrokh Mistree and decision analysis, Mistree's views the concept of "human computer cyborg" - the idea that we are all cyborgs now, since we interact so much with technology. I don't think Mistree originated the concept (I haven't managed to track down the origin of the phrase), and it was just a passing aside so we didn't discuss it in detail, but it made a huge impression on me. I mean, from a systems perspective, that makes a lot of sense - I incorporate my phone (say) into a human-machine system with myself multiple times per day. It may not be physically attached to me, but it's still an important part of me and how I interact with the world.

This concept assumed more importance as I began to take more interest in Assistive Technology. I had an interesting discussion with a clinician on the iPAM team back at ICORR 2007, where I differentiated inclusive design, rehabilitative technology and assistive technology thus:

Inclusive Design seeks to change the environment to fit the user by lowering demands;
Rehabilitation seeks to change the user by improving their capabilities; and
Assistive Technology intermediates between user and environment to lower demands.

The clinician disagreed with this - pointing out that "rehabilitation" can include prescribing AT. In other words, it was the human-machine system - the cyborg - that was changed in rehabilitation. We've since moved on to referring to "skills acquisition" in the work we do, partly because "rehabilitation" while suitable for post-stroke intervention, makes little sense when applied to helping children with motor impairments, and because we've since started applying the same principles and technologies to helping assess and train dentists and surgeons. But that conversation was another interesting step in the notion of the human machine cyborg, and Margrit Shildrick's talk was the first time I had seen this addressed explicitly (with the help of Google, I have since discovered quite a lot of writing on this area - it goes to show that sometimes you just need to know the right terms), and that's why I went. Indeed, it's the reason why I've been interested in working with Stuart Murray and Sita Popat here at Leeds on representations of the body - but that's another story.

Rethinking Prostheses

So, let me stumble into my impressions of the lecture itself. Shildrick noted that "embodiment is already technologically inflected", and that her interest was in "the point where distinction between naturally and artificially produced capabilities disappears". I don't have the language to understand the former, but the latter is certainly an interesting point. This crosses over a bit with some issues of embodied cognition and affordance that crop up in PAC Lab - action depends upon an interaction between a creature and environment. Whether the creature is a biological or mechanical entity, or a mixture of both is rather immaterial. I'm sure psychologists will correct me on that, since affordance is tied in with perception - we might query whether machines actually perceive affordances at the moment, but in this case, the discussion is about cyborg, not robot. The one doing the acting has some biological element. So far so good.

If I understood correctly, Shildrick made reference to Derrida's concept of "supplementarity, noting that organic and non-organic supplements of the body challenge its boundaries, that prostheses are "discursive frameworks as well as objects". Here we run into an issue with language and concepts - I'm not familiar with Derrida, or discursive frameworks (or whether that term carries a significant meaning beyond the literal), but I think the argument essentially amounted to the fact that prosthetics are not necessarily separate from the person using them, but can be part of that person. To my engineering mind, I would understand it as the person's "system boundary" shifting to incorporate the prosthetic - the prosthetic becoming a subsystem of the person, rather than a separate external system. Based on my limited discussions with users of prosthetics, and with Sita Popat (who is currently working with prosthetics users), this makes sense - some assimilate the prosthetics into their identity, some do not.

However, an interesting point arose about masculinity and prosthetics, Shildrick citing David Serlin's "Engineering Masculinity: Veterans and Prosthetics After World War Two", noting that much early work on prosthetics was focussed on allowing injured men to recover their masculinity, rather than being reduced to dependence on others, and noting that "functionality is often trumped by concern for appropriate gender roles". Again, I don't know the history here, but it's an interesting take - the balance between functionality and aesthetic, and which are more important, or what they should be. Shildrick argues that "the aesthetic body makes no distinction between natural and artificial", and argues for "including the non-organic as part of life".

    Her argument uses the concept of Deleuzian Assemblages (again - I'm not familiar with the work of Deleuze and Guattari cited) that occur in the disability field - not only the human-machine assemblages common with prosthetics and AT, but human-human assemblages (such as carers, family) and human-animal assemblages (such as guide dogs) . She also cites issues of phantom limbs (giving Alexa Wright's After Image as an example, visualising the position of missing limbs experienced by amputees), and the complex emotional experiences of recipients of organ donations, who must now incorporate an enormous change into their sense of identity. A lot of this is tied in with posthumanism - and a rethinking of bodily norms, which I think is what Shildrick was getting at. She notes performance artist Stelarc's third arm project, where he attaches and operates a third, prosthetic arm; Victoria Modesta's  spike leg performance in her Prototype video; and Lisa Bufano's incorporation of Queen Anne table legs as appendages in her dance routines. All are examples of prosthetics being used to supplement, or augment, rather than replace parts of the body. Shildrick concludes that this "opens up a new prosthetic imaginary... If we can't think differently, we can't do things differently."

   Intriguingly, I've jotted down two quotes whose context I can't remember and really wish I could. One says: "Humanised Swiss Army Knife", and the other "Radically though: technologised body can never be unproblematised, but it is already too late." I have no idea what either means, and I really wish I could remember! They obviously seemed significant at the time...

My Thoughts

So, I suspect a lot of the subtlety of the arguments was lost on me. Not being familiar with the texts or terms used definitely places me at a disadvantage, and I've deliberately not tried to read up on them to give you my innate response: I reserve the right to alter any or all of my opinions as I learn more on the subject.

Anyway, the core argument seems sensible to me, assuming I've interpreted it correctly: if we take our view of prosthetics (or, I would contend assistive and rehabilitation technology) as being to "fix" or restore a broken person to some "norm", then we are inevitably limiting their potential. I can see a certain merit in the "fix" line of thinking: firstly, the "norm" is what the majority of users of prosthetics and AT will have started from, and moving away from it exerts a loss of identity; and secondly, that we've designed the world around us based on those norms, so restoring the individual to that norm is the easiest way to get that person back into the environment.

I can also see some counter arguments to both points: that we make greater or lesser changes to our identities throughout our lives as our capabilities change (though few as abrupt or potentially disruptive as an amputation or, for example, stroke); that not everyone starts from the "norm" and the more we try to push everyone towards it the more difficult it becomes to be outside it; and that we can and should adapt the environment to reduce barriers anyway. Easier and more convenient for everyone to install lifts, drop kerbs and ramps rather than trying to design flying wheelchairs and pushchairs.

Shildrick's point about Deleuzian assemblages is interesting for exactly that reason. It recognises that actually, we aren't limited to technological solutions to impairment, since many inter-personal arrangements can be used, and nor do these relationships need to be constant at all times. To my engineering mind, this makes sense through the concept of systems. As a person, we all constitute a system made up of subsystems (nervous system, circulatory system, respiratory system, etc - all of which are made up of smaller systems, such as cells) and which interacts with a supersystem (our immediate environment and beyond - up to the level of the solar system, galaxy, eventually Universe - though few of us have to worry about things at that level!). Accordingly, one of the questions arises around where we draw the system boundary that defines ourselves. Is it just the biological system (our skin as system boundary?) or can it extend to incorporate prosthetics? Prosthetics may seem a natural inclusion, because of the norm mentioned above: if we understand the system boundary to be not our skin, but some Platonic ideal of the human as having two arms, two legs, two eyes, etc, etc then the prosthetic is automatically encompassed within that.

But if we're going to encompass prosthetics within the system boundary, why not wheelchairs? Crutches? Ventilators? We might take an insulin pump as being within the system if it's under the skin, but what about a Novopen that fulfils essentially the same function? Why not incorporate clothes? A smartphone, since almost everyone uses it as a prosthetic brain of some form? This gets a bit trite, since clearly we're dealing with some things (clothes, smartphones) that fall well within social norms, and some that fall without, but the point seems to stand. The system boundary of the person is constantly assembling and disassembling with other systems (people, animals, machines) to achieve its goals within a given environment.

Given that, I think Shildrick's argument is that we can rethink prostheses not just as a substitute for a body part to restore a lost "norm", but a space that can be rethought entirely based on what people want to achieve. Maybe I've got the wrong end of the stick - and naturally, there are all kinds of practical barriers to doing that. But movements such as OpenBionics and the Maker Movement begin to  make this more and more plausible. Perhaps the best Stelarc project to illustrate this is not the Third Hand but his extended arm - where the prosthetic offers capabilities not offered by an ordinary human hand. And this, of course, is where the engineering imagination comes in.

I mean, in a sense prosthetics have always been with humans: couldn't we see clothes as prosthetic fur? Weren't early spears, axes and arrows effectively a prosthetic version of the claws and teeth we lacked compared to other animals? Of course, at this point we're starting to get into post-humanism, trans-humanism, which opens up a whole other can of worms for discussion...

w/c 25th July: (un)Jamming

A slow week, the week just gone - so this'll be a short post. Few meetings and little admin, but little visible progress. On the plus side, after much gantt charting and rescheduling, I think I've finalised the design of my Fellowship application (huzzah!) so can get on to costings; and after much running and debugging of LabVIEW simulations, I've managed to determine that the results I had weren't flukes, so I've actually started writing the meat of the paper I've been working on. Also, I've nearly finished writing up my thoughts on Margrit Shildrick's presentation from... er, a month ago.

So, not much to present, really - but a couple of big sticking points cleared, which is quite a relief. Onwards!