What it is:
Some would argue that replicating the human brain in silicon is impossible. However, the folks over at Brains in Silicon of Stanford University might disagree. They’ve created a circuit board capable of simulating one million neurons and up to 6 billion synapses in real-time. Yes, that’s billion with a “B”. They call their new type of computer The Neurogrid.
The Neurogrid board boasts 16 of their Neurocore chips, with each one holding 256 x 256 “neurons”. It attempts to function like a brain by using analog signals for computations and digital signals for communication. “Soft-wires” can run between the silicon neurons, mimicking the brain’s synapses.
Be sure to stick around after the break, where we discuss the limitations of the Neurogrid, along with a video from its creators.
What it is not:
Though very neat and impressive, The Neurogrid fails at addressing a key component of Artificial Intelligence – the software architecture. Developing the hardware to replicate the vast interconnections of neurons is a great start, but we must also develop an understanding of how the brain is intelligent from a software side in order to use the hardware to its fullest potential.
Consider the problem with computers and pattern recognition. The human brain does this almost effortlessly. But this is a very difficult thing for a computer to do. Typically, we would start off by making some sort of template. Then we would compare the incoming data to the template, and make the appropriate decisions based on the comparison. What does it matter if you use an x86 machine, an FPGA or a Neurogrid board to carry out this task? The idea of comparing incoming data to a template is not how the brain recognizes patterns. There are no templates in your head.
So you argue “Well, the brain is a massively parallel analog computer, so once we can replicate this parallel structure in hardware, our current software models will work much better.”
Maybe. But consider the following analogy. You have one hundred stones that you need to move to the other side of a desert. And it takes one million steps to cross the desert. So you hire one hundred people to carry the stones across the desert. Hiring more than 100 people will not get the stones across the desert any faster. You still have to walk one million steps. *
There comes a point when simply adding more parallel processes will no longer equate to increased efficiency. We should ask ourselves if there are other ways to get across the desert, rather than trying to make the old way (walking) more efficient.
*Parallel analogy borrowed from “On Intelligence” by Jeff Hawkins.