Cat owner Amy Morgan says that her cat, Ruki, often hangs out on her laptop. “I think he figures I spend so much time staring at it that if he sits there he’ll get more attention.”
Lonely Ruki’s plan is a clever one, and it illustrates ways in which a cat can use logic and memory to get its needs met. Ruki remembers that Morgan often stares into her computer screen and figures that if he sits in that spot, he too will garner her deepest affection. Ruki’s behavior is not quite the stuff of science fiction, but what if another computer could manage to emulate Ruki’s actions, or at least the learning and memory part? Below, University of Michigan computer engineer Wei Lu weighs in on his latest project, a computer that’s modeled after the feline brain.
How the Catputer Works
Lu’s project, the “catputer,” has at its stem a device called a memristor — a gizmo that replaces the more traditional transistor and works like a biological synapse in your pet’s brain (and, for that matter, in yours). Synapses connect brain cells. Their connections are altered by experience. In mammals, the formation of new connections is what we call “learning.” If a computer can make new connections on its own based on experience (or electric voltages, in the case of the memristor), it can be said to have learned and remembered.
Secondly, traditional computers execute code linearly, or one thing at a time. Lu’s computer, like a mammalian brain, will perform multiple tasks simultaneously. “We’re building a computer in the same way that nature builds a brain,” he says. “The idea is to use a completely different paradigm than conventional computers.”
Why the Cat Brain?
“A cat’s brain is much simpler than a human brain,” explains Lu, adding that it is still “extremely difficult to replicate in complexity and efficiency.”
Cats may not be able to connect you to the Internet or help with a PowerPoint project, but they can, for example, recognize a face with greater speed and efficiency than a supercomputer. Even the most high-tech and powerful machines perform 83 times slower than the brain of your furry friend on tasks requiring multiple, simultaneous processes, like facial recognition, according to Lu.
Evolution of the Catputer
The end device Lu envisions is still several years from being complete. However, he has already demonstrated that his memristor can learn like a cat, using a process neuroscientists call “spike timing dependent plasticity,” which basically refers to the changing and strengthening connections between brain cells.
“We’ve shown that you can use voltage timing to increase or decrease the electrical conductance in this memristor-based system,” he explains. “In our brains, similar changes essentially give rise to long-term memory.”
The end result may not be anything you want to cuddle up with, but if Lu gets it right, it would be able to do things like find its way from your front door to your sofa in your crowded living room, even if you moved the sofa to the other end of the room. And unlike Morgan’s cat, Ruki, there will probably be no guilty feelings in the relationship.