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MIT Creates Chip to Model Synapses

MrSeb writes with this excerpt from an Extreme Tech article: "With 400 transistors and standard CMOS manufacturing techniques, a group of MIT researchers have created the first computer chip that mimics the analog, ion-based communication in a synapse between two neurons. Scientists and engineers have tried to fashion brain-like neural networks before, but transistor-transistor logic is fundamentally digital — and the brain is completely analog. Neurons do not suddenly flip from '0' to '1' — they can occupy an almost-infinite scale of analog, in-between values. You can approximate the analog function of synapses by using fuzzy logic (and by ladling on more processors), but that approach only goes so far. MIT's chip is dedicated to modeling every biological caveat in a single synapse. 'We now have a way to capture each and every ionic process that's going on in a neuron,' says Chi-Sang Poon, an MIT researcher who worked on the project. The next step? Scaling up the number of synapses and building specific parts of the brain, such as our visual processing or motor control systems. The long-term goal would be to provide bionic components that augment or replace parts of the human physiology, perhaps in blind or crippled people — and, of course, artificial intelligence. With current state-of-the-art technology it takes hours or days to simulate a simple brain circuit. With MIT's brain chip, the simulation is faster than the biological system itself."

44 of 220 comments (clear)

  1. The Interface will be a problem. by Robert+Zenz · · Score: 4, Insightful

    The problem is not providing such components, nor get them to work like the original nor getting it into your head. The real problem I see is interfacing with the rest of the brain.

    Because, let's face it, that's something every coder knows: Interfacing, working and supporting legacy systems just sucks.

    1. Re:The Interface will be a problem. by Eternauta3k · · Score: 3, Insightful

      Not just with the brain, but also with itself. I heard the brain is ridiculously well interconnected.

      --
      Yeah. Would you choose a neurosurgeon who pokes around people's brains in his spare time? I wouldn't.
    2. Re:The Interface will be a problem. by somersault · · Score: 2

      I think getting them to "work like the original" is the problem actually. That part covers interfacing all by itself. The brain is very highly interconnected in 3D.. and we don't have great 3D chip fabrication yet.

      --
      which is totally what she said
    3. Re:The Interface will be a problem. by ledow · · Score: 5, Interesting

      I think the REAL problem is that even the smallest brains have several billion neurons, with each having 10's of thousands of connections to other neurons. This chip simulates ONE such connection.

      That's a PCB-routing problem that you REALLY don't want, and way outside the scale of anything that we build (it's like every computer on the planet having 10,000 direct Ethernet connections to nearby computers - no switches, hubs, routers, etc. in order to simulate something approaching a small mouse's brain - not only a cabling and routing nightmare but where the hell do you plug it all in?). Not only that, by a real brain learns by breaking and creating connections all the time.

      The analog nature of the neuron isn't really the key to making "artificial brains" - the problem is simply scale. We will never be able to produce enough of these chips and tie them together well enough to produce anything conventionally interesting (and certainly nothing that we could actually analyse any better than the brain of any other species). If we did, it would be unmanageably unprogrammable and unpredictable. If it did anything interesting on its own, we'd never understand how or why it did that.

      And I think the claim that they know EVERYTHING about how a neuron works (at least one part of it) is optimistic at best.

    4. Re:The Interface will be a problem. by Narcocide · · Score: 5, Insightful

      I agree with everything about this statement except the word "never."

      Never is a pretty bold word. It puts you in a pretty gutsy mindset; one that isn't entirely productive to rational scientific analysis. The word "never" is pretty commonly seen in the company of "famous last words."

    5. Re:The Interface will be a problem. by six025 · · Score: 2

      If we did, it would be unmanageably unprogrammable and unpredictable.

      Should we just get it over with now, and call her EVE? ;-)

      Peace,
      Andy.

    6. Re:The Interface will be a problem. by vipw · · Score: 2

      They state that it takes 400 transistors. Intel fabs a 2 billion transistor chip. I don't think that really means that 5 million of these artificial neurons could be put in one die, but pretty I'm sure that they aren't planning to put millions of chips onto a board.

      With wafer-scale integration, and some long range signal propagation to emulate 3d, there's reason to think that fairly large systems can be emulated.

    7. Re:The Interface will be a problem. by agrif · · Score: 3, Informative

      "Your species is obsolete," the ghost comments smugly. "Inappropriately adapted to artificial realities. Poorly optimized circuitry, excessively complex low-bandwidth sensors, messily global variables..."

      Accelerando, by Charles Stross

    8. Re:The Interface will be a problem. by ultranova · · Score: 5, Interesting

      That's a PCB-routing problem that you REALLY don't want, and way outside the scale of anything that we build (it's like every computer on the planet having 10,000 direct Ethernet connections to nearby computers - no switches, hubs, routers, etc. in order to simulate something approaching a small mouse's brain - not only a cabling and routing nightmare but where the hell do you plug it all in?). Not only that, by a real brain learns by breaking and creating connections all the time.

      A single neuron-neuron connection has very low bandwidth, in effect transferring a single number (activation level) a few hundred times a second. Even if timing is important, you can simply accompany the level with a timestamp. A single 100 Mbs Ethernet connection is easily able to handle all those 10 000 connections.

      Also, most of those 10 000 connections are to nearby neurons, presumably because long-distance communication involves the same latency and energy penalties in the brains as it does anywhere else. There are efficient methods to auto-cluster a P2P network so as to minimize total length of connections, for example Freenet does this; so, you could, in theory, run a distributed neural simulator even on standard Internet technology. In fact, I suspect that it could be possible to achieve human-level or higher artificial intelligence with existant computer power in this method right now.

      So, who wants to start HAL@Home ?-)

      --

      Forget magic. Any technology distinguishable from divine power is insufficiently advanced.

    9. Re:The Interface will be a problem. by Smallpond · · Score: 2

      You don't need 3D chip fabrication to do 3D interconnects. The Connection Machine processors were interconnected in 8 dimensions, IIRC. Each node had 8 connections to its neighbors in a hypercube.

    10. Re:The Interface will be a problem. by Anonymous Coward · · Score: 3, Interesting

      I think the REAL problem is that even the smallest brains have several billion neurons, with each having 10's of thousands of connections to other neurons. This chip simulates ONE such connection.

      I give it 30 years at most.

      Let's say several=5. times 5000, (10 thousand dived by to so as to not double-count both ends) = 2,500 billion connection.Let's assume 400 transistors per connection as in this study that comes out to 10,000,000 billions transistors, not counting the possibility of time-multiplexed busses as mentioned in a comment below (as biological neurons are slow compared to transistors)

      According to wikipedia a Xilinx Virtex 7 FPGA (More similar to an array of neurons than a CPU) has 6.8 billion transistors. This means we need 1,470,588 times more transistors. That's less than 2^20.5, or 20.5 doublings, which according to Moore's law would be about 30 years or so.

      So even without multiprocessing, simplification of this design, and other simple improvements, this will be possible to put on some sort of chip in 30 years time.

      Never say never. 2042 will be the year of the brain in the desktop! :)

    11. Re:The Interface will be a problem. by StikyPad · · Score: 2

      Actually, the great thing about interfacing with the brain is that he brain adapts to the interface so the interface doesn't have to be adapted to the brain, per se. (By which I mean it's not terrible important where/how an input is connected, though obviously it must provide a signal that the brain can process). It's not only possible to do something like re-route an optic nerve to the auditory complex, it's possible to add additional inputs, both natural and man-made, and the brain will learn to process the additional information in short order.

  2. Was not expecting that.. by somersault · · Score: 3, Funny

    With MIT's brain chip, the simulation is faster than the biological system itself.

    Uh-oh.

    --
    which is totally what she said
    1. Re:Was not expecting that.. by Narcocide · · Score: 2

      Seems like you were thinking just I was thinking; Great, just enough time to enjoy a decade or two of flying cars built-and-designed entirely by machines before the machines realize we're all bad drivers and must be permanently restrained for our own well being.

  3. As it is written so shall it be done. by Narcocide · · Score: 3, Interesting

    Have you ever stood and stared at it, marveled at its beauty, its genius? Billions of people just living out their lives, oblivious. Did you know that the first Matrix was designed to be a perfect human world, where none suffered, where everyone would be happy? It was a disaster. No one would accept the program, entire crops were lost. Some believed we lacked the programming language to describe your perfect world, but I believe that, as a species, human beings define their reality through misery and suffering. The perfect world was a dream that your primitive cerebrum kept trying to wake up from. Which is why the Matrix was redesigned to this, the peak of your civilization. I say your civilization, because as soon as we started thinking for you it really became our civilization, which is of course what this is all about. Evolution, Morpheus, evolution. Like the dinosaur. Look out that window. You've had your time. The future is our world, Morpheus. The future is our time.

    -- Agent Smith (The Matrix)

  4. Well it's obvious by The+Creator · · Score: 5, Funny

    Due to their incompatibility with newer systems, meat bags are now obsolete.

    --

    FRA: STFU GTFO
    1. Re:Well it's obvious by mikael_j · · Score: 3, Funny

      I'm sure someone will build an interface for it, and then there will be an open source driver within days.

      If not that then let's at least hope our robotic overlords have it in their perfectly synchronized hearts to backport some of the major features...

      --
      Greylisting is to SMTP as NAT is to IPv4
  5. Better long-term goal: replace brains with these by Anonymous Coward · · Score: 2, Interesting

    "You cannot step twice in the same river". That means we are constantly changing. Over sufficiently long period, old person has all but died while new one has gradually taken over.

    Using that reasoning, we could replace biological brains bit-by-bit over long period of time, without killing the subject. In the end, if successful, the person has no more biological brains left. He'd have all digital brains. Backups, copies, performance tuning, higher clock rates, more memory, more devices, ... and immortality.

  6. My next startup idea by simoncpu+was+here · · Score: 3, Funny

    1. Build a farm of brain chips
    2. Expose the brain chips via an API
    3. Build a cloud service for brain chips
    4. Market as Brain Power on Demand(tm)!
    5. ???
    6. Profit!!

  7. I have my doubts by Anonymous Coward · · Score: 3, Insightful

    get them to work like the original

    Is this really something that we could do in the foreseeable future ? My understanding is that the brain programs itself (or we program it if you like) during the first years of our lives (5 to 7) for the most part. An empty new 'brain part' would act just like some parts of the brain act after a stroke I suspect, meaning that it'll take years and years to (re)train it.

    Similarly, children that grew up with animals alone, with little or no interaction with other humans (there were some cases) are never able to learn to speak fluently, because that part of the brain never fully develops (ie. is never programmed).

    AFAIK we don't know enough about how the brain works to pre-program such components and it would need to be strongly tuned to the destination brain, otherwise it won't work very well or at all. We know about the lower-level stuff (neurons, synapses) and some things about the higher-level (regions and general functions), but not much in between (though, I'm not a specialist).

    Even so, I can see some medical uses for this, for people with disabilities. Though nothing like what you see in 'Ghost in the Shell'.

    1. Re:I have my doubts by Ceriel+Nosforit · · Score: 2

      Creating an artificial human brain is too ethically loaded to even be considered in university research. They are more likely to try to get it to play a flight simulator since that's what someone did with a rat brain and they could compare their results, making for interesting data.

      Slashdot did however already welcome the flying rat overlords.

      --
      All rites reversed 2010
    2. Re:I have my doubts by jpapon · · Score: 5, Interesting
      You don't see how it's ethically loaded? Really?

      Would the artificial brain have rights? If you wiped its artificial neurons, would it be murder? If you give it control of a physical robot arm and it hurt someone, how and to what extent could you "punish" it? The ethical questions are virtually endless when you start to play "god". I would think that would be obvious.

      --
      -- Let us endeavor so to live that when we pass even the undertaker shall be sorry. -- M. Twain
    3. Re:I have my doubts by adam.dorsey · · Score: 4, Insightful

      My (hypothetical) baby is my (and my fiancee's) creation, why should I not have the right to "wipe" it?

      --
      You are still innocent until proven guilty. What's changed is what they do to innocent people. - notnAP, #26891325
    4. Re:I have my doubts by Anonymous Coward · · Score: 5, Funny

      You'll wipe your baby way more often than you'd want to.

    5. Re:I have my doubts by amck · · Score: 3, Interesting

      How about: does it suffer?
      Does creating a "human" inside a device where it can presumably sense, but have no limbs or autonomy consitute torture? Can you turn it off?

      Why is "being natural" a defining answer to these questions?

      --
      Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist
    6. Re:I have my doubts by Dr_Barnowl · · Score: 4, Insightful

      Application of intelligence is a natural biological process too, since the mind is running in a biochemical substrate (until the AI is working..)

      You're arguably more responsible for the AI than you are for the baby - it's possible to produce a baby without understanding what you are doing. You don't make an AI accidentally on a drunken prom date.

      The baby isn't even sentient until it reaches a certain level of development.

      So why do we value the child over the computer? Because we are biased towards humans? I'm not saying this is wrong, just saying it's not defensible from the purely intellectual point of view - if they are both sentient and have an imperative to survive, defending the destruction of the artificial sentience because it's easy and free of consequence is in the same ball park as shooting indigenous tribesmen because "they're only darkies".

    7. Re:I have my doubts by inasity_rules · · Score: 2

      Of course its defensible. The child has potential. An AI can be recreated if erased by supplying identical inputs and initial conditions. The child can not. This much is obvious. If I erase my AI, it isn't ended in the same way as if I erase a child. Why does everyone forget the implications of the "Artificial" part of "AI"? Too much sci fi?

      --
      I have determined that my sig is indeterminate.
    8. Re:I have my doubts by jpapon · · Score: 4, Insightful

      The AI, in essence is the sum of the inputs of its designers. Therefore they should decide what to do with the AI.

      I don't see how that follows. Just because you created something doesn't mean you should always have the power to destroy it.

      Neither did we define completely it's hardware.

      You seem to be saying that the degree to which something is designed by its creator determines whether or not they can destroy it. I find that completely irrelevant. If it is wrong to kill a human, then it is wrong to kill something else that has the intelligence of a human. It doesn't matter who created it or designed it, or to what to what degree they did so. If it has human-level intelligence, then it should possess human-level rights.

      --
      -- Let us endeavor so to live that when we pass even the undertaker shall be sorry. -- M. Twain
    9. Re:I have my doubts by jpapon · · Score: 3, Insightful

      If you kill a human they are gone.

      Gone in the sense of "not here". We have no way of proving anything beyond that.

      An AI may be re-creatable.

      We don't know one way or the other, so it's not really relevant. Besides, human consciousness might also be re-creatable. Can you say with 100% certainty that it is completely impossible to make an exact copy of the complete state of a human's neural network?

      Also, human level intelligence does not imply human level morality or ethics

      I would say that's exactly what it implies. I guess it depends on WHY you think killing humans is unethical, but killing insects, mice, cows, etc is fine. I say it's because of human intelligence. I can't figure out why you think so.

      --
      -- Let us endeavor so to live that when we pass even the undertaker shall be sorry. -- M. Twain
    10. Re:I have my doubts by Belial6 · · Score: 2

      You are missing the point. The fact that you are debating this at all is proof of the OP's assertion.

    11. Re:I have my doubts by Sentrion · · Score: 2

      Isn't this the argument used by religious nut jobs on Jihad or Crusade, burning heretics at the stake or stoning infidels to death? "God created them, then God told me to destroy them. Who am I to question the will of the creator or the authority of his holy scriptures?"

      Likewise, if my daddy owned slaves and the children of those slaves, and if my daddy bequeathed those slaves to me in his will at his death, then those slaves and children of those slaves become my property. Who has the right to deny me of property that was legally transferred to me (assuming pre-1860's US laws in southern states). Just because it is "legal" or fits well with some pre-existing theory of ethics, law, or property, does not mean that specific new situations should never be examined in a whole new light. Slavery is wrong not just because the Union won the Civil War, but because slavery is wrong.

      There are a lot of other things that are wrong but still legal, and even presumed by many to be ethical, but I won't get into that here today. But the presumption that ownership or creation confers some sort of universal god-like status is erroneous. Regardless of your opinion, people are not just going to stand by and let it happen. Just ask Muammar Gaddafi. Who's going to come to your rescue if you torture your creations in your lab and the revolt against you?

  8. It was 2011... by bassdrop · · Score: 2

    ...and war was beginning.

  9. But what about efficiency? by Pegasus · · Score: 4, Interesting

    It may be faster, but what about performance per watt? You know, the whole brain does everything on only 40-50 watts. How does this MIT product compare to brains in this area?

    1. Re:But what about efficiency? by chocapix · · Score: 2

      Wow, I never thought about it that way. A human brain consumes less power than a modern CPU (say, 100W).

      Plus, the brain does its own glucose burning and that's counted in the 50W. To compare fairly, you'd need to take into account the PSU efficiency, electrical grid losses and power plant efficiency in the CPU power. If we say 50% efficiency overall, that means 200W for the CPU.

      Just wow.

  10. Transistors are not digital by Ceriel+Nosforit · · Score: 3, Interesting

    The way I remember it is that a transistor stops a much larger current from passing through until a signal is put on the gate in the middle. Then the current that passes through is in proportion to the signal strength.

    The circuit becomes digital when we decide that only very small and very large voltages counts as 0s and 1s.

    --
    All rites reversed 2010
    1. Re:Transistors are not digital by multatuli · · Score: 2

      Transistors are analog. Transistor-transistor logic is digital.

    2. Re:Transistors are not digital by multatuli · · Score: 2

      Transistors are analog. Transistor-transistor logic is digital.

      Neurons are analog. What about neuron-neuron-logic?

      Some seem to expect it quantum-mechanical or even completely non-deterministic.
      Some are living up to that expectancy ;-)

  11. Never??? by mangu · · Score: 2, Insightful

    The analog nature of the neuron isn't really the key to making "artificial brains" - the problem is simply scale.

    Agreed.

    We will never be able to produce enough of these chips and tie them together well enough to produce anything conventionally interesting

    Shall we cue here all the "never" predictions of the last century? By the year 1900 there were lots of experts predicting we would never have flying machines, by 1950 experts were predicting the whole world would never need more than a dozen computers.

    Moore's law, or should we say Moore's phenomenon, has been showing how much electronic devices scale in the long run.

  12. Re:So to model analogue neurons... by Anonymous Coward · · Score: 5, Insightful

    I think you have to credit MIT researchers for knowing better where the cutting edge is than you, and the writers of the article for including the 1960s in this paragraph:

    'Previously, researchers had built circuits that could simulate the firing of an action potential, but not all of the circumstances that produce the potentials. “If you really want to mimic brain function realistically, you have to do more than just spiking. You have to capture the intracellular processes that are ion channel-based,” Poon says.'

    More than just spiking; from my AI lectures years ago I recall that the McCulloch-Pitts neuron model of the was a spiking model (excitatory inputs, inhibitory inputs, thresholds) etc.

  13. Putting many together by rust627 · · Score: 2

    so we build a synapse, and then link to more, and more, and before you know it we have a "brain",

    We could call it a Positronic Brain, sounds catchy, and marketable.

    And we really should enforce some rules to prevent a 'skynet' occurrence, not too many rules though,
    I'm sure we could distill the logic down to three simple rules ............

    --
    da da da dum indeed.
  14. Synapse firing event is not pure analog by wdef · · Score: 3, Insightful

    I might be out of date, but: the event itself requires the neuron's action potential to reach a threshold, then the synapse fires. It either fires or it does not. On or off. But the process of reaching the firing threshold is analog, since the physical geometry of the neuron and of its afferent neural feeds (inputs) determines at what point the neuron will fire. Neurotransmitter quantities in the synapse are also modifiable though eg by drugs and natural up/down regulation of receptors, enzymes or re-uptake inhibition. So a neuron is an analog computer having output with various amplitudes of on/off.

  15. Still a long, LONG way to go... by Pollux · · Score: 3, Insightful

    MIT’s chip — all 400 transistors (pictured below) — is dedicated to modeling every biological caveat in a single synapse. “We now have a way to capture each and every ionic process that’s going on in a neuron,” says Chi-Sang Poon, an MIT researcher who worked on the project.

    Just because you finally can recognize the letters of the alphabet doesn't mean you can speak the language.

    1. Re:Still a long, LONG way to go... by leptogenesis · · Score: 5, Informative

      Mod parent up. The linked article (and the MIT press release) are misleading. The closest thing I can find to a peer-reviewed publication by Poon has an abstract is here (no, I can't find anything throught the official EMBC channels--what a disgustingly closed conference):

      https://embs.papercept.net/conferences/scripts/abstract.pl?ConfID=14&Number=2328

      And there's some background on Poon's goals here:

      http://www.frontiersin.org/Journal/FullText.aspx?ART_DOI=10.3389/fnins.2011.00108&name=neuromorphic_engineering

      The goals seem to me to be about studying specific theories about information propagation across synapses as well as studying brain-computer interfaces. They never mention building a model of the entire visual system or any serious artificial intelligence. We have only the vaguest theories about how the visual system works beyond V1, and essentially no idea what properties of the synapse are important to make it happen.

      About two years ago, while I was still doing my undergraduate research in neural modeling, I recall that the particular theory they're talking about--spike-timing dependent plasticity--was quite controversial. It might have been simply an artifact of the way the NMDA receptor worked. Nobody seemed to have any cohesive theory for why it would lead to intelligence or learning, other than vague references to the well-established Hebb rule.

      Nor is it anything new. Remember this story from ages ago? Remember how well that returned on its promises of creating a real brain? That was spike-timing dependent plasticity as well, and unsurprisingly it never did anything resembling thought.

      Slashdot, can we please stop posting stories about people trying to make brains on chips and post stories about real AI research?

  16. Fundamentally Analog by tigre · · Score: 2

    The summary is way off. Transistors are analog devices, so TTL may behave digitally but that's only because a lot of work was done to make that happen. All that's happening here is taking analog devices with certain characteristics and using them to model an analog process with certain other characteristics. No small feat mind you.