Researchers at the University of Waterloo, Canada, have built the world’s most sophisticated artificial brain to date.Known as ‘Spaun’, (short for Semantic Pointer Architecture Unified Network), the model is able to simulate complex brain behaviour and is capable of thinking remembering, seeing and interacting with its environment using a mechanical arm.
Although Spaun currently exists in the simulated world inside a computer, it is one of the most advanced models ever created by scientists to understand how the human brain functions.
Unlike previous brain models, such as the 'million processor computer', which feature large networks of neurons with generally limited functions, Spaun’s 2.5 million neurons are designed to mimic our own brain’s structure with a prefrontal cortex, basal ganglia, and thalamus that allow it to ‘think’ about its environment and respond to the patterns it encounters.
"It has been interesting to see the reactions people have had to Spaun," says Chris Eliasmith, a professor in the department of philosophy at Waterloo University.
Even seasoned academics have not seen brain models that actually perform so many tasks. Models are typically small, and focus on one function."
A collaboration between neuroscientists and software engineers, Spaun receives its visual input via a 784 pixel digital camera this is relayed to its ‘thalamus’ which performs the same function it would in a human brain: processing the data it receives.
Once processed, the data is stored in Spaun’s neurons and directed to its basal ganglia which selects the appropriate action it should perform. Using this system, Spaun has been able to perfom well in a variety of IQ-testing tasks, including a test which demonstrates its understanding of numerical concepts.
However, Spaun’s mental abilities are not something to get too worried about just yet. As Eliasmith explains, they’re still a long way off being able to replicate anything like the sorts of tasks the human brain is able to perform.
"People are enormously more complicated," he says, "[Spaun] is nowhere near as intricate or sophisticated as human brains…it’s miles away."
It is hoped, however that Spaun could provide insights into what happens when parts of the brain become diseased and stop functioning. The researchers have already looked at what happens when you ‘kill’ some of the synthetic neurons.
"There are not only deep philosophical questions you can approach using this work — such as how the mind represents the world – but there are also very practical questions you can address about the diseased brain," Eliasmith said.
I believe that critical innovations are going to come from basic research like this. I can’t predict what specific industry or company is going to use this work or how — but I can list a lot that might."
The study is published in the current issue of the journal Science.