Cat brain: A step toward the electronic equivalent

Apr 14, 2010
Cat brain: A step toward the electronic equivalent

A cat can recognize a face faster and more efficiently than a supercomputer. That's one reason a feline brain is the model for a biologically-inspired computer project involving the University of Michigan.

U-M computer engineer Wei Lu has taken a step toward developing this revolutionary type of machine that could be capable of learning and recognizing, as well as making more complex decisions and performing more tasks simultaneously than conventional computers can.

Lu previously built a "," a device that replaces a traditional transistor and acts like a biological synapse, remembering past voltages it was subjected to. Now, he has demonstrated that this memristor can connect conventional circuits and support a process that is the basis for memory and learning in .

A paper on the research is published online in and is scheduled to appear in the forthcoming April edition of the journal.

"We are building a computer in the same way that nature builds a brain," said Lu, an assistant professor in the U-M Department of Electrical Engineering and Computer Science. "The idea is to use a completely different paradigm compared to conventional computers. The cat brain sets a realistic goal because it is much simpler than a human brain but still extremely difficult to replicate in complexity and efficiency."

Today's most sophisticated supercomputer can accomplish certain tasks with the brain functionality of a cat, but it's a massive machine with more than 140,000 central processing units and a dedicated power supply. And it still performs 83 times slower than a cat's brain, Lu wrote in his paper.

In a mammal's brain, neurons are connected to each other by synapses, which act as reconfigurable switches that can form pathways linking thousands of neurons. Most importantly, synapses remember these pathways based on the strength and timing of generated by the neurons.

In a conventional computer, logic and memory functions are located at different parts of the circuit and each computing unit is only connected to a handful of neighbors in the circuit. As a result, conventional computers execute code in a linear fashion, line by line, Lu said. They are excellent at performing relatively simple tasks with limited variables.

But a brain can perform many operations simultaneously, or in parallel. That's how we can recognize a face in an instant, but even a supercomputer would take much, much longer and consume much more energy in doing so.

So far, Lu has connected two electronic circuits with one memristor. He has demonstrated that this system is capable of a memory and learning process called "spike timing dependent plasticity." This type of plasticity refers to the ability of connections between to become stronger based on when they are stimulated in relation to each other. Spike timing dependent plasticity is thought to be the basis for memory and learning in mammalian brains.

"We show that we can use voltage timing to gradually increase or decrease the electrical conductance in this memristor-based system. In our brains, similar changes in synapse conductance essentially give rise to long term memory," Lu said.

The next step is to build a larger system, Lu said. His goal is achieve the sophistication of a supercomputer in a machine the size of a two-liter beverage container. That could be several years away.

Lu said an electronic analog of a cat brain would be able to think intelligently at the cat level. For example, if the task were to find the shortest route from the front door to the sofa in a house full of furniture, and the computer knows only the shape of the sofa, a conventional machine could accomplish this. But if you moved the sofa, it wouldn't realize the adjustment and find a new path. That's what engineers hope the cat would be capable of. The project's major funder, the Defense Advanced Research Projects Agency, isn't interested in sofas. But this illustrates the type of learning the machine is being designed for.

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3.8 / 5 (8) Apr 14, 2010
Fascinating, but I wonder, will the cat brain computer contain a circuit that, when it randomly decides to activate, turns the computer from a calm, properly functioning machine into a raging furball of teeth and claws? No cat computer will be complete without that feature.
2.6 / 5 (9) Apr 14, 2010
"We are building a computer in the same way that nature builds a brain,"

It is good to see someone so optimistic but I believe that we don't really know yet how nature builds a brain, any brain matter of fact. But I believe also that trying different approaches can help the neuroscience to understand how the brain works even when the model fails.
1.8 / 5 (4) Apr 14, 2010
I can see where this would have far reaching implications in the field of defense, or in crime investigation, since "cat brains" are excellent at detecting motion. If only we had "The Eye of a Tiger." Perhaps we can begin by JUST understanding how to replicate the function of their brain/eye control. But what is important is to realize that not all cats are alike. They are DEFINITELY not all alike! Breeds each have their own best features. If you want to research the cat brain computer, you should have an idea of which cat breed best serves your interests.
3.5 / 5 (6) Apr 14, 2010
I believe the idea here is to build a CPU that will have as many neuron-like memristors as cat's brain and see will it learn on its own. Cat's brain is just picked for comparison of number of neurons and complexity.
1.5 / 5 (6) Apr 14, 2010
they might succeed in building a disabled mentally retarded cat brain. but there are smart cats out there that would be harder to mimic than some stupid people out there. why not try to build a 'mentally retarded' brain.
2.5 / 5 (4) Apr 15, 2010
just needs a few additional features:
solar collector in the sun
& the ability to purr during S1
3.8 / 5 (4) Apr 15, 2010
they might succeed in building a disabled mentally retarded cat brain. but there are smart cats out there that would be harder to mimic than some stupid people out there. why not try to build a 'mentally retarded' brain.

Not only does that have nothing to do with the subject, it's also more than a little bit inappropriate. One could only assume that you would be "mentally retarded", judging from your writing ability.
1 / 5 (3) Apr 15, 2010
Better yet, maybe they could use zevkirsh's brain. It would be easy to build a computer based upon a single brain cell.
1.7 / 5 (3) Apr 15, 2010
yes, all it would need to be able to do is type poorly.
4.2 / 5 (5) Apr 15, 2010
After reading many of the comments posted here, I can see that a lot a people are really not understanding what is meant by the analogy to a cats brain. They are not saying that this computer will act like your pet cat, but it will have the level of neurological complexity of a cats brain.
not rated yet Apr 16, 2010
Should read Sturgeon's 'Case and the Dreamer'.
1 / 5 (1) Apr 17, 2010
Knowing the history of scientific endeavors, this ambitious yet benign project will probably end up twenty years from now as the world's most intelligent mousetrap.
1 / 5 (2) Apr 19, 2010
Just what we need, an un-trainable robot...
sheesh... (anyone thing that mimicking a trainable animal might be a better choice?)
not rated yet Jun 07, 2010
If the memristor CPU is successful, We can consult the computer on almost everything.