Connectionists: Brain-like computing fanfare and big data fanfare

[Axel Hutt]

----- Original Message -----

> [...]
> So once the neuroscience cell spikers get done analyzing 1000 or
> 10000 or even a 1M neurons
> at a circuit level.. we still won't know why someone makes decisions
> about the shoes they wear; much
> less any other mental function! Hopefully neuroimaging will be
> relevant again.

This brings me to a point that IMHO is very important : the right level of description of phenomena is hard to find. 
Sometimes some neuroscience research appears to me completely ill-posed, e.g. studying emotion evoked by music 
by analyzing intracranial Local Field Potentials or studying memory retrieval by single cell measurements, in my 
opinion this is not the way to go. Why ? 
Image the task to understand the underlying mechanism of a water wave, the ups and downs of the water surface. OK. What do physicists 
do ? They take (at best) the Navier-Stokes equation which considers the macroscopic properties of the fluid (compressibility etc.) 
and has a evolution variables mesoscopic (also measurable) variables. Nobody would even think to model single H2O-molecules, 
their properties, their interactions, simulate 1,2,3,10 or even hundreds and essecntially would find (probably) chaos for more than 
3 molecules --> impressive work but does not answer the original question. But, many neuroscientists think that this is the 
way to go to answer questions on macroscopic phenomena replacing the H2O-molecules by neurons, e.g. studying single cells 
to learn more about visual perception of faces or their storage. IMHO this is the wrong concept. 

What we need is the Navier-Stokes-like equation to explain mesoscopic properties on the neural population level. Yes, of course, 
you may say that the neural structures are too complex, but hey, fluids are complex as well. It just depends what you are 
looking for. If you want to describe the EEG evoked by high-frequency visual flickers where no cognition is involved or 
resting state activity, sleep, anaesthesia and others this Navier-Stokes-like model may give you goo answers. If you are more interested 
in cognitive effects, then things become more complicated and then the Navier-Stokes-like model is not sufficient, but 
may give you a hint. In physics, this comcept to start from a well-established model for simple systems and extend it 
in some way to attack more difficult problems has been very successful. A good candidate for such an equation in 
neuroscience may be a more realistic variant of a neural population model like neural mass/neural field models which 
already today can describe several features observed in EEG. 

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 
understand rudimentary mechanisms and less cognition ? I would like to see more research on fundamental phenomena in neuroscience. 
For some years now, I work actively in anaesthesia research and realize that people love to investigate effects of new mixtures of drugs, 
and generate much data in experiments with drugs whose receptor action is very poorly understood and the effects on the brain 
is far from being understood. Only few people try to describe theoretically what is going on in a neural population, when anaesthetic 
drugs change the receptor properties in the populations. This is a simple question, but still not answered. Sad enough, the pressure 
of pharma industry and the public interest in health (of funding agencies) is that high that these fundamental and essential questions 
are asked too seldom. 

Axel 

-- 

Dr. rer. nat. Axel Hutt, HDR 
INRIA CR Nancy - Grand Est 
Equipe NEUROSYS (Head) 
615, rue du Jardin Botanique 
54603 Villers-les-Nancy Cedex 
France 
http://www.loria.fr/~huttaxel 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.srv.cs.cmu.edu/pipermail/connectionists/attachments/20140125/c42e64a2/attachment.html>