Wednesday, November 24, 2010

Memristor Brains? No, But Likely a Step in the Right Direction

IEEE

Brian Wang presents a fascinating glimpse at the next stage of attempted machine intelligence -- driven by DARPA grants. The approach will likely involve the use of the Chua memristor -- or similar nano-scaled electronic devices. DARPA has specified its requirements for its new family of scalable and adaptive electronic thinking systems, and it appears that the memristor family of devices may be the best approach for government contractors wishing to collect their fees.
Researchers have suspected for decades that real artificial intelligence can't be done on traditional hardware, with its rigid adherence to Boolean logic and vast separation between memory and processing. But that knowledge was of little use until about two years ago, when HP built a new class of electronic device called a memristor. Before the memristor, it would have been impossible to create something with the form factor of a brain, the low power requirements, and the instantaneous internal communications. Turns out that those three things are key to making anything that resembles the brain and thus can be trained and coaxed to behave like a brain. In this case, form is function, or more accurately, function is hopeless without form.

Basically, memristors are small enough, cheap enough, and efficient enough to fill the bill. Perhaps most important, they have key characteristics that resemble those of synapses. That's why they will be a crucial enabler of an artificial intelligence worthy of the term.

The entity bankrolling the research that will yield this new artificial intelligence is the U.S. Defense Advanced Research Projects Agency (DARPA). When work on the brain-inspired microprocessor is complete, MoNETA's first starring role will likely be in the U.S. military, standing in for irreplaceable humans in scout vehicles searching for roadside bombs or navigating hostile terrain. But we don't expect it to spend much time confined to a niche. Within five years, powerful, brainlike systems will run on cheap and widely available hardware. _IEEE
A step in the right direction? Yes. The memristor family of devices will allow for a nanoscale fabrication of devices which function very much like a inter-neuronal synapse. Creating massively parallel circuits with such devices will allow designers to produce some fascinating -- and possibly quite functional -- computing devices.

But will these devices work anything like the human (or animal) brain? Not anytime soon. Because the designers seem focused on one small, rudimentary aspect of the human brain -- the neuronal synapse -- it is unlikely that they will achieve the "bigger picture" view of how human brains actually work for a long, long time, and after many failures.

But the development of electronic devices which imitate the synapse more accurately will place the pursuit of the machine brain on an entirely different level, above and away from the diminutive local optima which previous AI researchers have been struggling to achieve.

What will it take for memristor family devices to approach human brain level of function? First, it will require the knowledge that the brain has many distinct types of neurons, which form many distinct types of synapses. Next, it will require the awareness that synapses are just the meager beginning of the spark of intelligence. It is actually a vast ensemble of synaptic actions occurring in precise ways at precise times, and affecting precise modular systems of processors, which makes animal-style consciousness and intelligence possible.

Then, it will require the insight that intelligence is "embodied," to start the research down a long, difficult, but final road toward the creation of a rudimentary working machine intelligence.

If you are thinking that there are other approaches to intelligence than the animal or human approach, Al Fin cognitive scientists respond, "of course." But where are these alternative approaches? Where are their proofs of concept, their working prototypes? No closer today, than in the late 1940s and 1950s when absolutely brilliant computer scientists first believed they were within easy reach.

Human level machine intelligence would create a radical revolution of human existence at many levels, in many ways. But such a development does not appear to be very close. Certainly, humans are not ready for it. But a lot of things happen which humans are not prepared to experience. Better start getting ready now.

More: Brain Inspired Computing by Versace (via Brian Wang)

Moneta Neuromorphics Laboratory (via Brian Wang)

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