IBM's claim that it has designed the first brain simulation to exceed the scale of a cat's cortex is being dismissed as "a hoax and a PR stunt" by a rival scientist.
IBM researcher Dharmendra Modha last week hailed his company's new simulations as a "tremendous historic milestone" that will ultimately point the way to human scale brain simulations. But his boast was criticised in an open letter issued by Henry Markram, director of the Blue Brain Project in Switzerland, which is also attempting to reverse-engineer mammalian brains.
"This is light years away from a cat brain, not even close to an ant's brain in complexity," Markram wrote in an open letter which was sent to IBM Fellow and CTO Bernard Meyerson and reprinted on IEEE Spectrum. "It is highly unethical of Mohda to mislead the public in making people believe they have actually simulated a cat's brain. Absolutely shocking."
IBM voiced support for Modha’s work in a statement.
"IBM stands by the scientific integrity of the announcement on cognitive computing led by IBM in collaboration with Stanford University, University of Wisconsin-Madison, Cornell University, Columbia University Medical Center, University of California-Merced and Lawrence Berkeley National Laboratory," the IBM statement reads. "The cognitive computing team has achieved two milestones that indicate the feasibility of building a computing system that requires much less energy than today's supercomputers, and is modeled after the cognition of the brain. This is important interdisciplinary exploratory research bringing together computational neuroscience, microelectronics and neuroanatomy, and this work has been commented on favorably by others in the scientific community."
Despite the disagreement between Markram and Modha, the Blue Brain Project counts IBM as one of its technology partners. Modha is the lead researcher on IBM's cognitive computing project. In an interview before last week's announcement, Modha did clarify that the cat cortex simulation falls short of totally replicating a feline's brain.
"It's really not as powerful as a cat's brain in terms of function," he said. "What we have developed is an instrument of scientific discovery that can allow us to test various hypotheses of structures, dynamics and functions about the algorithms of the brain."
The cat brain simulation involved 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. Modha said the point is not to create robots that act like humans, but rather to use brainlike capabilities to create systems that can analyse streams of continually changing raw data in real time and thus help businesses make better decisions.
"This is a tremendous historic milestone," Modha said before last week's IBM announcement. "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."
Markram, however, said the cat brain simulation involves only "point neurons," which are "missing missing 99.999% of the brain, no branches, no detailed ion channels, the simplest possible equation you can imagine to simulate a neuron, totally trivial synapses."
A paper on the cat cortex simulation titled "The Cat is Out of the Bag," authored by Modha and several colleagues, was awarded the Gordon Bell Prize at last week's SC09 supercomputing conference. The prize, issued by the Association for Computing Machinery, recognises achievement in high performance computing applications.
Markram objected to the Bell Prize decision, writing that "I never realized that such trivial and unethical behavior would actually be rewarded."
He went on to call the cat brain research an "outright deception of the public."
"All these kinds of simulations are trivial and have been around for decades," Markram wrote. "There is no qualified neuroscientist on the planet that would agree that this is even close to a cat's brain."
Markram reiterated that he believes IBM's announcement is "a clear case of scientific deception of the public" and gave additional reasons supporting his contention.
"They claim to have simulated over a billion neurons interacting," Markram wrote. "Their so-called 'neurons' are the tiniest of points you can imagine, a microscopic dot. Over 98% of the volume of a neuron is branches (like a tree). They just cut off all the branches and roots and took a point in the middle of the trunk to represent a entire neuron. In real life, each segment of the branches of a neuron contains dozens of ion channels that powerfully controls the information processing in a neuron. They have none of that. Neurons contain tens of thousands of proteins that form a network with tens of millions of interactions. These interactions are incredibly complex and will require solving millions of differential equations. They have none of that."
Markram went on to say that "These points they simulated and the synapses that they use for communication are literally millions of times simpler than a real cat brain. So they have not even simulated a cat's brain at one millionth of its complexity."