A team from the University of Waterloo have created the world’s largest functioning simulation of the human brain. And it’s called SPAUN.
The Semantic Pointer Architecture Unified Network – or “Spaun”, for short – is a functioning computer simulation of the human brain that can count, remember lists and even solve some basic elements of an IQ test.
The simulation was created by Chris Eliasmith and a team from the University of Waterloo’s Centre for Theoretical Neuroscience and has 2.5 million simulated neurons – or nerve cells – organized to resemble cranial subsystems such as the prefrontal cortex and basal ganglia. A real human brain, by the way, has about 85 billion neurons – in other words, Spaun is quite low-powered in comparison. The system was built using software called “Nengo,” which according to the Nengo website is “a graphical and scripting based software package for simulating large-scale neural systems.”
Spaun sees data via a 28×28 digital eye and uses a robotic arm to write out its responses. For example, when Spaun is shown a series of numbers – “1, 2, 3; 5, 6, 7; and 3, 4, ?” – its robotic arm will write out the answer “5″.
While Spaun is only able to perform basic tasks, the simulation nonetheless requites a considerable amount of resources. Although it’s run on a supercomputer, each second of simulation requires about 2.5 hours of computer time, meaning that it takes Spaun hours to perform a task a human could do almost instantaneously.
Interestingly, Spaun exhibits some of the same characteristics as humans. For example, it’s better at remembering items at the beginning or end of a list than it is at remembering items that fall in the middle and it hesitates before delivering its answers. “We weren’t surprised that it could do tasks, but we were often surprised that subtle features like the time it took or the errors it made were the same as for humans,” Eliasmith told Nature.
Eliasmith hopes to improve Spaun so that it is eventually able to self-learn. “Instead of us giving it strategies for performing these tasks, it would be able to discover strategies based on experience, just like humans do,” he said.
You can see videos of Spaun in action at the Nengo website.