IBM's quest to build a computer that can mimic the human brain has reached a new milestone, with what IBM calls the first brain simulation to exceed the scale of a cat's cortex.   The simulation involves 1 billion spiking neurons and 10 trillion individual learning synapses, and was performed on an IBM Blue Gene/P supercomputer with 147,456 processors and 144TB of main memory.   "This is a tremendous historic milestone," said Dharmendra Modha, the lead researcher on IBM's cognitive computing project. "It shows that if we build a supercomputer with 1 exaflop computing power and 4 petabytes of main memory -- which might be possible within the decade -- then a human-scale simulation in real time will become possible."   Ultimately, IBM wants to build a computer that "simulates and emulates the brain's abilities for sensation, perception, action, interaction and cognition, while rivaling the brain's low power and energy consumption and compact size." The goal is not to create robots that act like humans, but rather to create systems that can analyze streams of continually changing raw data in real time, and thus help businesses make better decisions.   "We are trying to build intelligent business machines," Modha said. "As the amount of raw sensory data we create continues to grow massively and the world becomes instrumented and interconnected, businesses will need intelligence to monitor, prioritize, adapt and make rapid decisions."   The project will last multiple decades, Modha said. Today, simulations are as powerful as 4.5 percent of a human cerebral cortex. But with current technology a human simulation would require a billion times more energy than is consumed by the human brain itself, a statistic that illustrates just how remarkable our brains really are.   [Fujitsu aims for 10-petaflop supercomputer]   [China aims for petaflop computer in 2010]   "Mother nature has discovered a computing architecture that we have yet to invent," Modha said. The brain "is more efficient than our computers by a factor of a billion, and it has the uncanny ability to integrate sight, hearing, taste, touch, smell, and to integrate this ambiguous streaming torrent of data and act on it."   Eventually, researchers believe they can build a computer that not only mimics the function of the human brain but does so in a package of roughly the same physical size. "One of our goals is to build a chip with 1 million neurons and 10 billion synapses per square centimeter," Modha said. "It is extremely challenging but you don't change the world by solving simple problems."   The cognitive computing project started more than four years ago, and is part of the Systems of Neuromorphic Adaptive Plastic Scalable Electronics (SyNAPSE) program led by the Defense Advanced Research Projects Agency, which has provided IBM $21 million in funding.    In addition to IBM, the project involves researchers at Stanford University, Cornell University, Columbia University, University of Wisconsin-Madison, and UC-Merced. The Blue Gene/P supercomputer that performed the cat cortex simulation is based at the Lawrence Livermore National Laboratory.