On the quarter-mile walk between his office at the ÉcolePolytechniqueFédérale de Lausanne (EPFL) in Switzerland and the nerve center of his research across campus, Henry Markram gets a brisk reminder of the rapidly narrowing gap between human and machine. At one point he passes a museumlike display filled with the relics of old supercomputers, a memorial to their technological limitations. At the end of his trip he confronts his IBM Blue Gene/P—shiny, black, and sloped on one side like a sports car. That supercomputer is the center-piece of the Blue Brain Project, tasked with simulating every aspect of the workings of a living brain.
Markram, the 49-year-old founder and codirector of the Brain Mind Institute at the EPFL, is the project’s leader and cheerleader. A South African neuroscientist, he received his doctorate from the Weizmann Institute of Science in Israel and studied as a Fulbright Scholar at the National Institutes of Health. For the past 17 years he and his team have been collecting data on the neocortex, the part of the brain that lets us think, speak, and remember. The plan is to build software that can use fundamental biological rules to make comprehensive, three-dimensional simulations of mammalian brains—including, eventually, that of a human. Such a digital re-creation that matches all the behaviors and structures of a biological brain would provide an unprecedented opportunity to study the fundamental nature of cognition and of disorders such as depression and schizophrenia.
Until recently there was no computer powerful enough to take all our knowledge of the brain and apply it to a model. Blue Gene has changed that. It contains four monolithic, refrigerator-size machines, each of which processes data at a peak speed of 56 tera-flops—a teraflop being one trillion floating-point operations per second. At $2 million per rack, this Blue Gene is not cheap, but it is affordable enough to give Markram a shot with this ambitious project. Each of Blue Gene’s more than 16,000 processors is used to simulate approximately one thousand virtual neurons.
By getting the neurons to interact with one another, Markram’s team makes the computer operate like a brain. The system was built to emulate just a single neocortical unit from a two-week-old rat, but he hopes to make it more powerful, using more design rules to build more accurate and larger models that could eventually attempt to rival the one in its creator’s head. The project is now in the running for 1 billion euros (about $1.4 billion) of funding over the next 10 years, thanks to a big-science initiative backed by the European Union. Markram’s Human Brain Project coalition was selected a semifinalist last spring; the final decisions will be made next year. By ramping up the processing capability to capture more data and derive more rules, a fully functioning model of a human brain can be built by the turn of the decade, Markram believes. By that point, supercomputers should be capable of running a quintillion (10^18) calculations per second, which is what will be necessary for these first simulations. Markram spoke with discover contributor David Kushner to lay out his vision of recasting the brain in digital form.
Most people—even most scientists—still regard the brain’s inner workings as a mystery. Yet you believe not only that you can understand the brain but that you can, in effect, re-create it. What do you see that others do not?
