by Nicolas Guyon
It is an exciting time to be studying the brain. In the last one hundred years, we have acquired a deeper understanding of how its 100 billion neurons are born, grow, and connect. But as the discovery of DNA changed the larger field of biology, giving a physical structure to how building blocks of life are encrypted, neuroscience is waiting for a similar breakthrough. How are thoughts encoded and how do they emerge from the neuronal circuitry of our brains? Which laws govern the way neurons are connected and the dynamics of their interactions? How are these translated into our intricate mental processes?
In a quest to answer these kind of questions, as well as to develop more high-tech tools to study the brain, the European Commission has given an unprecedented 1 billion euros to the Human Brain Project (HBP). This collaborative project, that spans over one hundred neuroscience and technology groups across the world, aims to build a large-scale computer simulation of the entire brain using data collected from experimental studies. Both the United States (with the BRAIN initiative) and China have since followed suit, with their own highly funded neuroscience initiatives focused on brain mapping and neurological diseases.
More recently, the HBP has been the subject of controversy as some of the scientists involved in the program are concerned that this type of research is diverting funding from more realistic studies, towards a kind of highly unrealistic Utopian dream. In an Open Letter to the European Commission, these skeptical scientists expressed their concern about the current course of the Human Brain Project and are calling for the close examination of both the scientific policy and management of the HBP. They are worried about the decision to stop funding the experimental neuroscience part of the project, which had the task to collect data from non-human-primates, rodents and humans and instead focus solely on the computer modeling. “Numerical simulations and ‘big data’ are essential in modern science, but they do not alone yield understanding. Building a massive database to feed simulations without corrective loops between hypotheses and experimental tests seems, at best, a waste of time and money”, wrote Yves Frégnac and Gilles Laurent, two eminent European neuroscientists, in an article published in Nature about the change of focus of the HBP.
One of the authors of the contestation letter, Zachary Mainen, a neuroscientist at the Champalimaud Center for the Unknown in Lisbon, is not only concerned about the transparency behind the administration of the project but also its feasibility. “It’s like a moonshot, but before we knew how to build an airplane,” he said to the New York Times. “We can’t simulate the 302 neurons in a nematode brain. It’s a bit premature to simulate the 100 billion neurons in a human brain”, he added, in reference to the mapping of the C. elegans nervous system back in 1986, which has not yet been able to give us information about how the nematode behaves.
One thing is certain, the director of the project, Henry Markram, will have the task of making the program more open and to show that it can, like a Jules Verne novel, leave the realm of science fiction and make it to the Moon.