New human-brain chip can be adjusted for cannabis effect

Hey, chip for brains!

Researchers at the Massachusetts Institute of Technology have come up with a better way to simulate the processing that goes on in the human brain, and you hardware enthusiasts out there will appreciate this one.

Rather than simulate the firing and spiking of a bunch of neurons in software on massive clusters of computer chips, MIT researchers have created a digital chip with analog properties that emulates the flow of ions between connected brain cells and therefore can directly simulate how neurons actually fire across their synapses.

In a paper published this week in the Proceedings of the National Academy of Sciences, boffins describe a chip consisting of 400 transistors that mimics the ion flows in synapse between two real-world neurons and – they hope – will allow electronic circuits to mimic the "plasticity" that human brains have ­ the ability to process, store, and adapt to new information. (Particularly when you concuss them or when their owners allow them to say something really stupid.)

Guy Rachmuth, a former postdoc Harvard-MIT Division of Health Sciences and Technology, is lead author of the paper, with Chi-Sang Poon, a principal research scientist at the lab, Mark Bear, a professor of neuroscience at MIT, and Harel Shouval of the University of Texas Medical School as co-authors.

The human brain has about 100 billion neurons, more or less (more for El Reg readers, and less for El Reg hacks), and each neuron has multiple synapses between them oozing neurotransmitters as the brain responds to stimuli from the outside world, creating an ion channel of flowing and charged sodium, potassium, and calcium ions in the synapse and eventually allowing an electric signal, called an action potential, to fire from one neuron to the other. When this happens, your brain remembers to do things, like duck a punch or keep your heart beating. (Often at the same time.)

MIT neuron chip

MIT's synapse emulation chip

What Rachmuth and his fellow boffins at MIT and UT have figured out how to do is to create a circuit that allows for current to flow through the transistors in an analog fashion, just like the ions in the ion channel in a synapse. And thus, the synapse chip emulate, in hardware, what a real synapse is doing in your head instead of relying on software to emulate all of this running on a cluster of ARM, Power, or x86 processors.

While other researchers have created chips that emulate the synaptic firing, this one can emulate the ion flows underlying the firing, and therefore do a better job simulating neurons. "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 explained in a statement announcing the paper. "We can tweak the parameters of the circuit to match specific ion channels. We now have a way to capture each and every ionic process that's going on in a neuron."

These ion channels are, explained Poon and Rachmuth in the paper, the key to two underlying pieces of brain microcode: long-term potentiation (LTP) and long-term depression (LTD). No, this is not what you had when you were a teenager and what you get as a grumpy old git when you don't realize it.

Rather, these are the means by which changes in ion flows that strengthen or weaken the links between synapses. Those links are how we learn and forget things. By simulating the ion flows directly, the synapse chip made by MIT will be able to test theories about how LTP and LTD occur.

Some people think we learn based on the frequency of synaptic firing, others think the timing of sequences of firing are more important. Arrays of these synaptic chips will be able to show what works best empirically in hardware simulation and then extrapolate back to what happens in real brains.

Interestingly, there is a whole class of researchers who think that endo-cannabinoids, which have a structure similar to THC – the active ingredient in the pot you never inhaled – and which are involved in many brain functions including appetite, pain suppression, and memory, are affiliated with LTD. First, I knew my brain made its own opiates, but I did not know it made its own pot. And second, of course these endo-cannabinoids make you hungry and forget stuff – like the fact that you already knew that before you started designing the chip.

The MIT boffins are planning to use their synaptic chip to model specific parts of the brain, such as the visual cortex. And the upside is that compared to trying to simulate it in software on a supercomputer cluster, as researchers are now trying to do, by using the analog synaptic chip, the simulation will run faster than your own brain does. (The brain has a 65Hz to 80Hz cycle time, roughly, and it decreases with age, which is very likely why time seems to pass so slowly during grade school and so fast when you have finally got the kids out of the house.)

The interesting thing to ponder is how many synapses could be crammed onto a modern chip. The new "Interlagos" 16-core Opteron 6200 processors from Advanced Micro Devices have 2.4 billion transistors, so in theory, the 32 nanometer processes commonly used today could put at 6 million electronic synapses on the chips.

Forgetting the silicon you would need to interconnect the synaptic modules on the chip, or chip-to-chip interconnects and assuming 8,000 synapses per neuron, you would need around 133 million of these multi-synaptic chips to emulate the full brain and it would burn about 15.3 megawatts just for the chips alone, ignoring any other supporting electronics needed for the chips or the cooling for such a system. You brain does it in 20 watts, but it will think many orders of magnitude slower. Especially considering all the cannabis. ®

Similar topics

Broader topics

Other stories you might like

  • Will this be one of the world's first RISC-V laptops?
    A sneak peek at a notebook that could be revealed this year

    Pic As Apple and Qualcomm push for more Arm adoption in the notebook space, we have come across a photo of what could become one of the world's first laptops to use the open-source RISC-V instruction set architecture.

    In an interview with The Register, Calista Redmond, CEO of RISC-V International, signaled we will see a RISC-V laptop revealed sometime this year as the ISA's governing body works to garner more financial and development support from large companies.

    It turns out Philipp Tomsich, chair of RISC-V International's software committee, dangled a photo of what could likely be the laptop in question earlier this month in front of RISC-V Week attendees in Paris.

    Continue reading
  • Did hoodwink Americans with IRS facial-recognition tech, senators ask
    Biz tells us: Won't someone please think of the ... fraud we've stopped

    Democrat senators want the FTC to investigate "evidence of deceptive statements" made by regarding the facial-recognition technology it controversially built for Uncle Sam. made headlines this year when the IRS said US taxpayers would have to enroll in the startup's facial-recognition system to access their tax records in the future. After a public backlash, the IRS reconsidered its plans, and said taxpayers could choose non-biometric methods to verify their identity with the agency online.

    Just before the IRS controversy, said it uses one-to-one face comparisons. "Our one-to-one face match is comparable to taking a selfie to unlock a smartphone. does not use one-to-many facial recognition, which is more complex and problematic. Further, privacy is core to our mission and we do not sell the personal information of our users," it said in January.

    Continue reading
  • Meet Wizard Spider, the multimillion-dollar gang behind Conti, Ryuk malware
    Russia-linked crime-as-a-service crew is rich, professional – and investing in R&D

    Analysis Wizard Spider, the Russia-linked crew behind high-profile malware Conti, Ryuk and Trickbot, has grown over the past five years into a multimillion-dollar organization that has built a corporate-like operating model, a year-long study has found.

    In a technical report this week, the folks at Prodaft, which has been tracking the cybercrime gang since 2021, outlined its own findings on Wizard Spider, supplemented by info that leaked about the Conti operation in February after the crooks publicly sided with Russia during the illegal invasion of Ukraine.

    What Prodaft found was a gang sitting on assets worth hundreds of millions of dollars funneled from multiple sophisticated malware variants. Wizard Spider, we're told, runs as a business with a complex network of subgroups and teams that target specific types of software, and has associations with other well-known miscreants, including those behind REvil and Qbot (also known as Qakbot or Pinkslipbot).

    Continue reading

Biting the hand that feeds IT © 1998–2022