Tag Archives: DARPA
Scientists have linked up two silicon-based artificial neurons with a biological one across multiple countries into a fully-functional network. Using standard internet protocols, they established a chain of communication whereby an artificial neuron controls a living, biological one, and passes on the info to another artificial one.
We’ve talked plenty about brain-computer interfaces and novel computer chips that resemble the brain. We’ve covered how those “neuromorphic” chips could link up into tremendously powerful computing entities, using engineered communication nodes called artificial synapses.
As Moore’s law is dying, we even said that neuromorphic computing is one path towards the future of extremely powerful, low energy consumption artificial neural network-based computing—in hardware—that could in theory better link up with the brain. Because the chips “speak” the brain’s language, in theory they could become neuroprosthesis hubs far more advanced and “natural” than anything currently possible.
This month, an international team put all of those ingredients together, turning theory into reality.
The three labs, scattered across Padova, Italy, Zurich, Switzerland, and Southampton, England, collaborated to create a fully self-controlled, hybrid artificial-biological neural network that communicated using biological principles, but over the internet.
The three-neuron network, linked through artificial synapses that emulate the real thing, was able to reproduce a classic neuroscience experiment that’s considered the basis of learning and memory in the brain. In other words, artificial neuron and synapse “chips” have progressed to the point where they can actually use a biological neuron intermediary to form a circuit that, at least partially, behaves like the real thing.
That’s not to say cyborg brains are coming soon. The simulation only recreated a small network that supports excitatory transmission in the hippocampus—a critical region that supports memory—and most brain functions require enormous cross-talk between numerous neurons and circuits. Nevertheless, the study is a jaw-dropping demonstration of how far we’ve come in recreating biological neurons and synapses in artificial hardware.
And perhaps one day, the currently “experimental” neuromorphic hardware will be integrated into broken biological neural circuits as bridges to restore movement, memory, personality, and even a sense of self.
The Artificial Brain Boom
One important thing: this study relies heavily on a decade of research into neuromorphic computing, or the implementation of brain functions inside computer chips.
The best-known example is perhaps IBM’s TrueNorth, which leveraged the brain’s computational principles to build a completely different computer than what we have today. Today’s computers run on a von Neumann architecture, in which memory and processing modules are physically separate. In contrast, the brain’s computing and memory are simultaneously achieved at synapses, small “hubs” on individual neurons that talk to adjacent ones.
Because memory and processing occur on the same site, biological neurons don’t have to shuttle data back and forth between processing and storage compartments, massively reducing processing time and energy use. What’s more, a neuron’s history will also influence how it behaves in the future, increasing flexibility and adaptability compared to computers. With the rise of deep learning, which loosely mimics neural processing as the prima donna of AI, the need to reduce power while boosting speed and flexible learning is becoming ever more tantamount in the AI community.
Neuromorphic computing was partially born out of this need. Most chips utilize special ingredients that change their resistance (or other physical characteristics) to mimic how a neuron might adapt to stimulation. Some chips emulate a whole neuron, that is, how it responds to a history of stimulation—does it get easier or harder to fire? Others imitate synapses themselves, that is, how easily they will pass on the information to another neuron.
Although single neuromorphic chips have proven to be far more efficient and powerful than current computer chips running machine learning algorithms in toy problems, so far few people have tried putting the artificial components together with biological ones in the ultimate test.
That’s what this study did.
A Hybrid Network
Still with me? Let’s talk network.
It’s gonna sound complicated, but remember: learning is the formation of neural networks, and neurons that fire together wire together. To rephrase: when learning, neurons will spontaneously organize into networks so that future instances will re-trigger the entire network. To “wire” together, downstream neurons will become more responsive to their upstream neural partners, so that even a whisper will cause them to activate. In contrast, some types of stimulation will cause the downstream neuron to “chill out” so that only an upstream “shout” will trigger downstream activation.
Both these properties—easier or harder to activate downstream neurons—are essentially how the brain forms connections. The “amping up,” in neuroscience jargon, is long-term potentiation (LTP), whereas the down-tuning is LTD (long-term depression). These two phenomena were first discovered in the rodent hippocampus more than half a century ago, and ever since have been considered as the biological basis of how the brain learns and remembers, and implicated in neurological problems such as addition (seriously, you can’t pass Neuro 101 without learning about LTP and LTD!).
So it’s perhaps especially salient that one of the first artificial-brain hybrid networks recapitulated this classic result.
To visualize: the three-neuron network began in Switzerland, with an artificial neuron with the badass name of “silicon spiking neuron.” That neuron is linked to an artificial synapse, a “memristor” located in the UK, which is then linked to a biological rat neuron cultured in Italy. The rat neuron has a “smart” microelectrode, controlled by the artificial synapse, to stimulate it. This is the artificial-to-biological pathway.
Meanwhile, the rat neuron in Italy also has electrodes that listen in on its electrical signaling. This signaling is passed back to another artificial synapse in the UK, which is then used to control a second artificial neuron back in Switzerland. This is the biological-to-artificial pathway back. As a testimony in how far we’ve come in digitizing neural signaling, all of the biological neural responses are digitized and sent over the internet to control its far-out artificial partner.
Here’s the crux: to demonstrate a functional neural network, just having the biological neuron passively “pass on” electrical stimulation isn’t enough. It has to show the capacity to learn, that is, to be able to mimic the amping up and down-tuning that are LTP and LTD, respectively.
You’ve probably guessed the results: certain stimulation patterns to the first artificial neuron in Switzerland changed how the artificial synapse in the UK operated. This, in turn, changed the stimulation to the biological neuron, so that it either amped up or toned down depending on the input.
Similarly, the response of the biological neuron altered the second artificial synapse, which then controlled the output of the second artificial neuron. Altogether, the biological and artificial components seamlessly linked up, over thousands of miles, into a functional neural circuit.
So…I’m still picking my jaw up off the floor.
It’s utterly insane seeing a classic neuroscience learning experiment repeated with an integrated network with artificial components. That said, a three-neuron network is far from the thousands of synapses (if not more) needed to truly re-establish a broken neural circuit in the hippocampus, which DARPA has been aiming to do. And LTP/LTD has come under fire recently as the de facto brain mechanism for learning, though so far they remain cemented as neuroscience dogma.
However, this is one of the few studies where you see fields coming together. As Richard Feynman famously said, “What I cannot recreate, I cannot understand.” Even though neuromorphic chips were built on a high-level rather than molecular-level understanding of how neurons work, the study shows that artificial versions can still synapse with their biological counterparts. We’re not just on the right path towards understanding the brain, we’re recreating it, in hardware—if just a little.
While the study doesn’t have immediate use cases, practically it does boost both the neuromorphic computing and neuroprosthetic fields.
“We are very excited with this new development,” said study author Dr. Themis Prodromakis at the University of Southampton. “On one side it sets the basis for a novel scenario that was never encountered during natural evolution, where biological and artificial neurons are linked together and communicate across global networks; laying the foundations for the Internet of Neuro-electronics. On the other hand, it brings new prospects to neuroprosthetic technologies, paving the way towards research into replacing dysfunctional parts of the brain with AI chips.”
Image Credit: Gerd Altmann from Pixabay Continue reading
When you imagine an exoskeleton, chances are it might look a bit like the Guardian XO from Sarcos Robotics. The XO is literally a robot you wear (or maybe, it wears you). The suit’s powered limbs sense your movements and match their position to yours with little latency to give you effortless superstrength and endurance—lifting 200 pounds will feel like 10.
A vision of robots and humankind working together in harmony. Now, isn’t that nice?
Of course, there isn’t anything terribly novel about an exoskeleton. We’ve seen plenty of concepts and demonstrations in the last decade. These include light exoskeletons tailored to industrial settings—some of which are being tested out by the likes of Honda—and healthcare exoskeletons that support the elderly or folks with disabilities.
Full-body powered robotic exoskeletons are a bit rarer, which makes the Sarcos suit pretty cool to look at. But like all things in robotics, practicality matters as much as vision. It’s worth asking: Will anyone buy and use the thing? Is it more than a concept video?
Sarcos thinks so, and they’re excited about it. “If you were to ask the question, what does 30 years and $300 million look like,” Sarcos CEO, Ben Wolff, told IEEE Spectrum, “you’re going to see it downstairs.”
The XO appears to check a few key boxes. For one, it’s user friendly. According to Sarcos, it only takes a few minutes for the uninitiated to strap in and get up to speed. Feeling comfortable doing work with the suit takes a few hours. This is thanks to a high degree of sensor-based automation that allows the robot to seamlessly match its user’s movements.
The XO can also operate for more than a few minutes. It has two hours of battery life, and with spares on hand, it can go all day. The batteries are hot-swappable, meaning you can replace a drained battery with a new one without shutting the system down.
The suit is aimed at manufacturing, where workers are regularly moving heavy stuff around. Additionally, Wolff told CNET, the suit could see military use. But that doesn’t mean Avatar-style combat. The XO, Wolff said, is primarily about logistics (lifting and moving heavy loads) and isn’t designed to be armored, so it won’t likely see the front lines.
The system will set customers back $100,000 a year to rent, which sounds like a lot, but for industrial or military purposes, the six-figure rental may not deter would-be customers if the suit proves itself a useful bit of equipment. (And it’s reasonable to imagine the price coming down as the technology becomes more commonplace and competitors arrive.)
Sarcos got into exoskeletons a couple decades ago and was originally funded by the military (like many robotics endeavors). Videos hit YouTube as long ago as 2008, but after announcing the company was taking orders for the XO earlier this year, Sarcos says they’ll deliver the first alpha units in January, which is a notable milestone.
Broadly, robotics has advanced a lot in recent years. YouTube sensations like Boston Dynamics have regularly earned millions of views (and inevitably, headlines stoking robot fear). They went from tethered treadmill sessions to untethered backflips off boxes. While today’s robots really are vastly superior to their ancestors, they’ve struggled to prove themselves useful. A counterpoint to flashy YouTube videos, the DARPA Robotics Challenge gave birth to another meme altogether. Robots falling over. Often and awkwardly.
This year marks some of the first commercial fruits of a few decades’ research. Boston Dynamics recently started offering its robot dog, Spot, to select customers in 2019. Whether this proves to be a headline-worthy flash in the pan or something sustainable remains to be seen. But between robots with more autonomy and exoskeletons like the XO, the exoskeleton variety will likely be easier to make more practical for various uses.
Whereas autonomous robots require highly advanced automation to navigate uncertain and ever-changing conditions—automation which, at the moment, remains largely elusive (though the likes of Google are pairing the latest AI with robots to tackle the problem)—an exoskeleton mainly requires physical automation. The really hard bits, like navigating and recognizing and interacting with objects, are outsourced to its human operator.
As it turns out, for today’s robots the best AI is still us. We may yet get chipper automatons like Rosy the Robot, but until then, for complicated applications, we’ll strap into our mechs for their strength and endurance, and they’ll wear us for our brains.
Image Credit: Sarcos Robotics Continue reading