Final Report Summary - NERVI (From single neurons to visual perception)
The NerVi project has allowed to ground neuroscience on solid mathematical foundations. This is important because of the challenges that need to be addressed in order to cure neurodegenerative diseases that affect the world aging populations. We are convinced that in order to extract information from the gigantic data bases that are collected everyday in hospitals one needs guiding lights, i.e. theoretical tools, to help the clinicians make sense out of these data. These theories are also important to better understand the functioning of the healthy brain and to help us in our search for discovering what makes us humans.
Working in this direction we have developed a theory that allows to describe the activity of very large populations of individual neurons such as those found in the functional areas of the human brain. This theory is similar in spirit to what has been achieved by physicists in fluid mechanics where the equations that describe the fluids, e.g. the Navier-Stokes equations, are derived from the description of the motion of their molecules, ignoring many of the details of their interactions that are irrelevant at the scale of interest. It is useful in that it can make predictions about the activity of brain areas that can be measured with the methods of neuro-imaging (functional magnetic resonance imaging, magneto-encephalography, electro-encephalography). This activity is believed to be the stuff our perceptions, feelings, decision-making processes are made on. One of the fascinating prediction of this theory is that the noise that is overwhelmingly present at the level of the individual neurons (e.g. the ion channels or the synapses) is in effect necessary for the brain to be functional.
We have also confronted our theoretical, mathematical, work to experimental measurements. For example we have used it, working in collaboration with experimenters, to account for certain aspects of the human perception of visual motion. This example was chosen for several reasons. One is the fact that the perception of visual motion is fundamental in our every-day life, another one is that previous work by others indicates that the laws that govern visual perception are similar to those that govern many other mental processes. Our work has uncovered one facet of this seemingly ’universal’ principle that requires that the neuron populations operate close to what mathematicians call a bifurcation, i.e. a sudden change in the behavior of the system under study, for reasons of efficiency and flexibility. Potentially and in the long term this could be used to help visually impaired people. Another example of the confronting our theoretical work to the real world is in the area of one neurological disorder, epilepsy. Using again the bifurcation idea we have shed new light on the neural processes that may be at the origin of epileptic seizures. This has also potential long term applications in the treatment of some epileptic patients.
An important outcome of the project has been to contribute creating and putting on the map a new field, mathematical neuroscience, which we hope will continue entertaining a rich dialog with experimenters and clinicians in order to fasten the pace toward a better understanding of what remains largely a terra incognita, the human brain.
Working in this direction we have developed a theory that allows to describe the activity of very large populations of individual neurons such as those found in the functional areas of the human brain. This theory is similar in spirit to what has been achieved by physicists in fluid mechanics where the equations that describe the fluids, e.g. the Navier-Stokes equations, are derived from the description of the motion of their molecules, ignoring many of the details of their interactions that are irrelevant at the scale of interest. It is useful in that it can make predictions about the activity of brain areas that can be measured with the methods of neuro-imaging (functional magnetic resonance imaging, magneto-encephalography, electro-encephalography). This activity is believed to be the stuff our perceptions, feelings, decision-making processes are made on. One of the fascinating prediction of this theory is that the noise that is overwhelmingly present at the level of the individual neurons (e.g. the ion channels or the synapses) is in effect necessary for the brain to be functional.
We have also confronted our theoretical, mathematical, work to experimental measurements. For example we have used it, working in collaboration with experimenters, to account for certain aspects of the human perception of visual motion. This example was chosen for several reasons. One is the fact that the perception of visual motion is fundamental in our every-day life, another one is that previous work by others indicates that the laws that govern visual perception are similar to those that govern many other mental processes. Our work has uncovered one facet of this seemingly ’universal’ principle that requires that the neuron populations operate close to what mathematicians call a bifurcation, i.e. a sudden change in the behavior of the system under study, for reasons of efficiency and flexibility. Potentially and in the long term this could be used to help visually impaired people. Another example of the confronting our theoretical work to the real world is in the area of one neurological disorder, epilepsy. Using again the bifurcation idea we have shed new light on the neural processes that may be at the origin of epileptic seizures. This has also potential long term applications in the treatment of some epileptic patients.
An important outcome of the project has been to contribute creating and putting on the map a new field, mathematical neuroscience, which we hope will continue entertaining a rich dialog with experimenters and clinicians in order to fasten the pace toward a better understanding of what remains largely a terra incognita, the human brain.