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So once the neuroscience cell spikers get done analyzing 1000 or 10000 or even a 1M neurons<br>
at a circuit level.. we still won't know why someone makes decisions about the shoes they wear; much<br>
less any other mental function! Hopefully neuroimaging will be relevant again.<br></blockquote><br>This brings me to a point that IMHO is very important : the right level of description of phenomena is hard to find.<br>Sometimes some neuroscience research appears to me completely ill-posed, e.g. studying emotion evoked by music<br>by analyzing intracranial Local Field Potentials or studying memory retrieval by single cell measurements, in my <br>opinion this is not the way to go. Why ?<br>Image the task to understand the underlying mechanism of a water wave, the ups and downs of the water surface. OK. What do physicists<br>do ? They take (at best) the Navier-Stokes equation which considers the macroscopic properties of the fluid (compressibility etc.) <br>and has a evolution variables mesoscopic (also measurable) variables. Nobody would even think to model single H2O-molecules,<br>their properties, their interactions, simulate 1,2,3,10 or even hundreds and essecntially would find (probably) chaos for more than<br>3 molecules --> impressive work but does not answer the original question. But, many neuroscientists think that this is the <br>way to go to answer questions on macroscopic phenomena replacing the H2O-molecules by neurons, e.g. studying single cells<br>to learn more about visual perception of faces or their storage. IMHO this is the wrong concept.<br><br>What we need is the Navier-Stokes-like equation to explain mesoscopic properties on the neural population level. Yes, of course,<br>you may say that the neural structures are too complex, but hey, fluids are complex as well. It just depends what you are <br>looking for. If you want to describe the EEG evoked by high-frequency visual flickers where no cognition is involved or<br>resting state activity, sleep, anaesthesia and others this Navier-Stokes-like model may give you goo answers. If you are more interested<br>in cognitive effects, then things become more complicated and then the Navier-Stokes-like model is not sufficient, but<br>may give you a hint. In physics, this comcept to start from a well-established model for simple systems and extend it<br>in some way to attack more difficult problems has been very successful. A good candidate for such an equation in <br>neuroscience may be a more realistic variant of a neural population model like neural mass/neural field models which<br>already today can describe several features observed in EEG. <br><br>This brings me to another point: would it not be good to invest more effort in neuroscience (as already several of you have said) to <br>understand rudimentary mechanisms and less cognition ? I would like to see more research on fundamental phenomena in neuroscience.<br>For some years now, I work actively in anaesthesia research and realize that people love to investigate effects of new mixtures of drugs,<br>and generate much data in experiments with drugs whose receptor action is very poorly understood and the effects on the brain <br>is far from being understood. Only few people try to describe theoretically what is going on in a neural population, when anaesthetic <br>drugs change the receptor properties in the populations. This is a simple question, but still not answered. Sad enough, the pressure <br>of pharma industry and the public interest in health (of funding agencies) is that high that these fundamental and essential questions<br>are asked too seldom. <br><br>Axel<br><br><br><br><br>-- <br><div><span name="x"></span><br>Dr. rer. nat. Axel Hutt, HDR <br>INRIA CR Nancy - Grand Est <br>Equipe NEUROSYS (Head)<br>615, rue du Jardin Botanique<br>54603 Villers-les-Nancy Cedex<br>France<br>http://www.loria.fr/~huttaxel<span name="x"></span><br></div></div></body></html>