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Studying consciousness had been seen as mystical or unscientific

Francis Crick, the co-discoverer of the DNA double helix, defined consciousness as the greatest unsolved problem in biology. The first major international conference of the Human Brain Project, held recently in Barcelona, has focused on the challenges and advances in its study. Jesús Méndez, of the scientific news agency SINC, spoke with the local organiser of the conference, Mavi Sánchez Vives.

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What role does the study of consciousness play within the Human Brain Project? There are many groups in the project that coincided on dealing with the issue of consciousness, whether on the basis of basic, clinical research and even of philosophy. This has made it become a main axis and that this theme has been chosen for the first major international conference of the Human Brain Project. At what stage are we in the study of consciousness? How much do we really know? Well, if we compare it, for example, with the great theories of physics, we must admit that we’re just starting. It was a topic that science was almost unwilling to deal with in the twentieth century; it was much disregarded among scientists because it was seen as unscientific, more typical of the religious field. But we must also bear in mind that problems of the alteration of consciousness such as those suffered by patients in a coma are a matter that some clinicians face daily, and in that sense there are advances: we are trying to standardize measures that tell us of a patient’s state of consciousness or even allow us to communicate with them through brain-computer interfaces. Right now there are two great models that try to explain consciousness. What do they consist of? (Sánchez Vives shares the question with Johan Storm, professor at the University of Oslo and organizer of the meeting). “There are many models, but it is true that two of them are the most famous,” explains Storm. “One is that of the Global Neural Network, which studies the neural networks and the areas of the brain needed for consciousness to emerge. The second is the so-called Integrated Information Theory, which is more ambitious and tries to explain consciousness in its entirety through mathematical models. There’s a lot of debate about which one is better: I think the answer will lie somewhere in between,” says Storm. (Returning to Sánchez Vives). The latter model seems to have been the basis for one of the tools that have been developed to measure the level of consciousness, including patients in coma, the so-called ‘disturbance complexity index’, which in a way quantifies the echo that a magnetic stimulation produces in the brain. What does it consist of? Yes, you have to think of the brain cortex as a network. If the network is very segregated, if everything acts very locally, there is no awareness. But if it’s too integrated, if everything connects with everything else, the response is very stereotyped and there is no awareness either. Consciousness occurs when there is a balance between integration and segregation - according to the Integrated Information Theory model. What we do is disrupt the network with an electrical or magnetic stimulus: if the network is segregated, the response to the stimulus (the echo) is very short, not very complex; if it’s very integrated, there will be a general response that disappears very soon. But if that balance occurs, relationships are established between the nodes of the network that produce a much more complex response. This index has been validated in studies in people who are awake, asleep, under anaesthesia, in patients with different levels of coma ... The good thing for the doctor is that this index is an objective number that correlates quite well with the level of consciousness. This is particularly valuable in situations in which the patient doesn’t respond but may be conscious, which is why it’s necessary to identify objective measures of consciousness… Full article here: