RobotTemplar

You may be right about the slow pace of medical science. I guess I have a little hope because of the increasing pace of technological progress, especially in the field of biotechnology. A whole culture is developing around the idea of biological engineering, even outside the group of professional scientists. Look up DIY Bio, for example. What you have to say about artificial organs is very interesting. This is the kind of feedback I was hoping for when I started this thread. I have given some thought to this issue of cutting off normal sensory feedback, namely most (all?) of your peripheral nervous system. But since people with severe spinal injuries are able to survive (so far as I have heard), I don't think this would be a problem. Performing this operation without having at least one of the major sensory systems functioning to some degree (probably vision or hearing) would seem more like torture than medical intervention.

A detail in one of my posts really bothers me, but it is too late for me to edit it. Can I petition to a moderator or something to get them to edit it for me?

Yes, blood clots are one problem that occurred to me. Advances in biomedical sciences may soon allow us to circumvent this, however. My understanding of the organ scaffold/seeding process is that it eliminates the problem of rejection: http://singularityhu...-in-rats-video/ See the Nova program "Can We Live Forever?" You use organs from animals or human donors - it doesn't matter - and you dissolve away all the cells, leaving only a protein "scaffold". Then somehow tissue engineers are able to reseed it with the transplantee's own cells, so there is no problem of rejection. Other methods of producing organs may be on the way - look up 3d printing of organs, for example. I have read that artificial organs in that past have been problematic because it is difficult to make them small enough for implantation. However, when you are dealing with an immobile brain in a vat, it doesn't matter if your artificial heart or lung is several cubic meters in volume. I wonder if this might change things? I honestly have no idea. I have seen Fleming's patent online. I will have to look up the book. I have heard about the Soviet experiments. Remember that we aren't concerned about reconnecting nerves. We use a brain computer interface (one or more electrodes), implanted most likely into the motor cortex. This could allow you to control any number of robotic prostheses (perhaps one of the BCIs would allow the brain to switch to another prosthetic with a thought). This is completely doable right now, except eventually your brain will form scar tissue, and the BCI(s) will stop working. The brain wouldn't be totally immobile, because it could use telepresent robots, for example. If BCIs ever become advanced enough (this is looking perhaps many decades into the future, if ever...or it might happen sooner), then it might be able to control a teleprescent robot designed to look exactly like its cast off human body (already done, to some degree). I am guessing that the peripheral nervous system would be much much easier to model on a computer than a CNS (because you don't have to worry about individual cells forming several thousand connections between each other...I think), so this also leaves open all sorts of cool options involving virtual reality.

When I first read about a brain computer interface being used to enable a monkey to control a robot arm, this was the first ... application that occurred to me. As wonderful as the human body is, it is also very messy (eating, excreting, and so on), and it is vulnerable, on account of its very complexity, to many maladies (mainly, I am thinking of cancer, organ failure, and aging) which are difficult to treat. So anyway, let us assume in the near future that the problems of neural scarring for BCIs and growth of artificial organs are resolved. Let us also say that we have the technology for electronic eyes and ears by this time that are close in capability to the real thing (etc. for any kinds of sensory prostheses). Finally, let us assume that one is able to surgically remove the brain and hook it up to a perfusion system before cell death sets in. This may sound absurd, but apparently at least one full on head transplant has been done (do a google search), and I think hooking up a brain to a perfusion system specifically made for the purpose might be a lot easier (apparently cooling the brain allows it to last a lot longer without a blood supply). This perfusion system would consist of nodes to which the grown organs could be easily connected - allowing for easy replacement, as needed, very much unlike the human body. The artifical blood would be enriched with food, oxygen, hormones, or as needed. The brain would be able to switch between any number of physical actuation systems (robotic arms and so on) in order to interact with the environment. If BCIs ever became advanced enough, it might even be able to retain its human shape in the form of a virtual avatar or telepresent robot. So yes, this may be a silly idea. In this scenario with artificial organs being easily obtainable, there is no real advantage except that you will perhaps be less likely to die from sudden organ failure. And you will still eventually go senile or have a stroke or die from brain cancer (though if we can do away with these problems...!). But are there any actual physiological obstacles? Just how feasible is this scheme of an artificial perfusion system with attached organs? EDIT: This system could also be implemented with artificial (minimally biological) organs, I suppose. That's how I first envisioned it, before I heard about what scientists are doing with seeding organ scaffolds from other animals. It wouldn't matter if an artificial heart or lung or whatnot was as big as a house, as long as it worked.

Okay, my report is a little late. First of all, thank you for introducing me to google scholar. Although I can't read any of the articles (wants $), the place is a treasure trove of information. I suppose I am accustomed to being able to find any information I want digitally (or thinking that I am able to do this), but perhaps this is not really the case for science. ---------------------------------- I spent a couple hours searching around, but unfortunately I have not been able to really add on to my basic understanding. Electrodes can get smaller, and circuitry or programming can get smarter, but it seems like the basic mechanism for a nerve interface is pretty uniform. With a brain computer interface, you have an electrode that is placed close enough to pick up electrical signal residue from neurons (as to how this works in detail, I do not know - electricity is still mostly a mystery to me). Nerve stimulation is the same concept in reverse. Apparently you may also be able to achieve stimulation using magnetism - but I am not yet an electrical engineer ... I can't explain to you how this works. The capabilities of noninvasive external (outside the skull) electrodes are very limited because the skull blocks signals, and for some reason you are only able to get a reading of more global brain activity with these electrodes (I think read this in a book about frontiers in brain science, called "The Scientific American: Brave New Brain"...I may have also read something to this effect in "More Than Human" by Ramez Naam). I am assuming you have heard about the monkey controlling a robotic arm with a BCI. That is what got me really interested in this. Basically this sort of thing works because there is a lot of redundancy in the brain (protection against injury, and/or somehow related to neuroplasticity?). So implanted BCIs can be pretty powerful. But of course a robotic arm with only a couple of actuators is very different from a human or animal arm, which has probably thousands (hundreds of thousands or millions?) of muscle fibers, allowing for much finer control. -------------------------- As for sources, I mentioned the two books I have read about this. Most of anything else I have said will also be covered in the following article: http://computer.hows...r-interface.htm If this site is not trustworthy, then I am pretty much screwed, because 90% of my technical education up to this point has come from working through its articles.... I am sorry if I didn't tell you anything new. The above pretty much summarizes my understanding of this subject.

That does help, thank you. The main part of the confusion that I had coming into this thread is resolved. Though really, I'm just going to have to do some hard studying for the level of detail I am interested in. Questioning an expert in real time, I think, is a very efficient learning strategy and an art form, but it doesn't translate so well into a forum medium. I will give a shot at this, since you took the time to answer my questions. I will add this in in another post by, let's say, 6pm tomorrow. I intend for my major to be in either electrical engineering or bioengineering (plus I want to learn about BCIs regardless), so it is easy to justify this time expenditure.

Could you (or any knowledgeable person) perhaps expand on the statement I have in bold? Does this mean that it is not the case that there are cortical cells at some level that have a one to one correspondence with sensory neurons? Thank you for this edifying segment... Aha, this is exactly what I wanted to know. So, does the spinal cord consist primarily (or entirely) of nerve axons, then? Really really long nerve axons? That's cool, I never made the cochlear implant connection. From reading parts of the Wikipedia article, my guess would be because nerve activation is achieved using an electromagnetic field, and the implant never actually comes in contact with the nerve. The BCIs I have read about (not including stuff like artificial retinas) have always been for reading from the brain, not to it. Also... I have a question about spinal nerves. Does a spinal nerve as it nears the spinal cord also, like the spinal cord, contain individual nerves that correspond with tactile inputs at that level (so in a cross section you might be able to identify, "oh, this nerve is for this point on the forefinger, and this one is for...")? Finally, just to make sure that I'm getting this right, the nerves coming out of the spinal cord in the image below are in fact the spinal nerves, correct? http://upload.wikime...tem_diagram.png

I have been really curious about BCIs for a while now, and I have read a lot about them. One of the coolest technologies I could see coming from this kind of research is a spinal cord interface, ala the Matrix, except that the major application would probably be for people with spinal cord injuries (or disembodied brains...mwahahaa). I have been thinking how such an interface could be implemented (and whether it will even be feasible at all in the near future, without radical bio- and genetic engineering advancements) but I find that I am hindered by a degree of ignorance about the physiology of the nervous system that cannot easily be rectified by surfing the internet or reading Wikipedia. It seems like asking a knowledgeable person (what I am doing on this forum) might be a lot faster than searching through textbooks. So, my questions. How does the brain distinguish between an input from, say, your right index finger versus your right middle finger? Is this like vision, where you have individual cells at some level that correspond with parts of the visual field? I read that axons from cells in your motor cortex actually extend down to the base of your spinal cord...so do cells from the sensory part of the NS (like the part that senses touch to your index finger) similarly have axons that extend upward through the spinal cord, perhaps meeting the motor cortex outgrowths at the top? I am very unclear about how this works. Would a cross section of the spinal cord then have axons from from every part of your "tactile field" below that section of the spinal cord? I have read things that indicate that some complex signaling mechanism and neurotransmitters may play a role. Please help ease my confusion. Another question, much simpler, if you can answer it: would a spinal interface consisting solely of small enough, biocompatible electrodes be enough to transmit/receive signals (I assume not)? Or would it be necessary to have some kind of mechanism that could feed out neurotransmitters and and accept them as inputs?