Differential EEG

NMF nm_fournier at ns.sympatico.ca
Tue Mar 9 15:03:33 EST 2004


> I've not been reading in the Neuroscience
> stacks, but I've not seen a single Generalized
> Report of efforts to use EEG to follow the
> 'burning fuses' of action potentials.

That's because an EEG doesn't allow you to track a single action potential.
All it is a gross outcome of activity from millions of neurons.  What your
seeing isn't really action potentials per se, but rather the summation of
activity from a variety of different neurons.    I'm failing to see your
point.

> If it's as you say, then you should contact
> a good Science Writer [say, Natalie Angier,
> William Broad, John Noble Wilford, Kenneth
> Chaing, at The =New York Times= Science
> desk], and get this stuff into the Popular Med-
> ia. [The =NYT= also employs some pretty-Good
> Graphical-depiction Talent.]
>
> It's too-important to sit in the stacks, so I en-
> courage you to get it Communicated.

I don't need to contact the press, this is all well known in the literature
and in the community.  I encourage you to start reading current papers
published in the neurosciences.

>
> Folks need to hook-up with accelerator-
> detector Engineers. That's all.
>
> > Volume
> > conduction and inverse problems will still present a problem in the
> > localization approach you suggested.
>
> Only be-cause folks've not, yet, hooked-
> up with accelerator-detector Engineers.
>

Well all your suggesting here is that technology needs to change, a point
that I agree with you.  I can't comment on your statement that "hooking up
with accelerator-detector Engineers"  will be beneficial.

> If other scanning techniques can see into
> the depths, EEG can, too, and it will, as
> soon as folks hook-up with accelerator-
> detector Engineers.

I agree with you.  This is an engineering question.  Obviously in the
magical world of possibility anything can happen.  The issue is that this
doesn't validate anything you have been previously saying.  If a complete
paradigm shift and technological revolution is required in order for your
theory to be acceptable then fine.  But basing such arguments on  "what
if's" doens't make them verifiable, nor do they make them false.  They just
remain as interesting ideas for arm chair thinking and the occassional pub
discussion.

I agree with you, if the techniques and approaches change then perhaps we
can gain insight using your approach.  However, right now it meaningless.
The same argument can be given to space travel.  One day if we can develop
"warp-speed" we can travel to distant. Sure.  Perhaps we will, however, in
the here and the now the point is irrelevant.

> I do not 'overlook' the fact that there're a hundred
> billion neurons in-there.
>
> It's just that every one of them is directionally-
> mapped within the neural Topology.

Well you have presented these concepts numerous times; however, I still find
them ambiguous.  I don't agree that every single neuron will be mapped
regarding one specific directional mapping within neurotopology.  The
problem with this, at least in my opinion, is that theoretically the loss of
a single unit (if in an appropriate or critical location) can cause the
potential break down in the organization and functionality of the remaining
aggregates.  Furthermore, what will be mapped within the topology will be at
any given moment will be influenced by the activity of all the aggregates
within the brain space at that single moment in time.  I don't think the
directionally mapping is fixated or static, but would rather be dynamic.  (I
may misunderstand what you are saying; however, this is what the data
suggests and what my own work seems to verify).

> If I ever get a chance to work with actual data,
> I Expect that what I'll find is that folks've been
> 'ignoring' this neural-topological-mapping - be-
> cause their approach is Conservative with re-
> spect to the Maths that's been handed-down
> since Berger. I Expect I'll find that folks've
> been Preserving the Maths, rather than doing-
> Neuroscience.

Well I don't know what to say.  Until I see your own mathematical approach,
I will remain skeptical.

> For instance, it would be useful if electrodes
> were embedded in 'patch'-arrays that were
> addressible in the 'same' way that current
> LCDs are addressed. This, alone [which is
> 'immediately'-doable] would =greatly= enhance
> resolution.
>
> Such 'patch-arrays' could be used in localized
> EEG recordings - to look, in focussed ways, at
> particular sub-dynamics, with each patch having
> its own CPU so that analysis could occur in-paral-
> lel, in real-'time'.

I agree; however, the problems stated before still remain.  There has been
some interesting work by Nunez regarding the physics and mathematical
approach regarding source localization from EEG dynamics.

> Then the patch-array-density could be gradually
> increased to 'full'-coverage.
>
> I don't know what, if anything, it'd yield, but I'd
> also like to investigate using electrodes that're
> suspended at distances separating them from
> the brain. I'd want to look for another usable
> energy-gradient - another 'ramp' - another 'dif-
> ferential'. Superficially, it'd be even more 'foggy',
> but that's just-it - a relative-'fog' 'differential' is
> Useful in sorting-out what's 'foggy', but less-
> 'foggy'.

Interesting concept. The data has suggested that the time-varying magnetic
fields generated by the brain that are most important in mediating processes
involved with consciousness  can most likely interact with exogeneous
magnetic fields at a location that are a small distance extending off the
scalp.






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