oscillations RETRACTION & CLARIFICATION

Kenneth Collins k.p.collins at worldnet.att.net
Wed Aug 7 04:43:18 EST 2002


RETRACTION & CLARIFICATION

Kenneth Collins wrote in message ...
>Hi Dr. Jones,
>
>Your post is Beautiful, and I've no problem with anything that's
>in-it except with respect to the final sentence.

RETRACTION & CLARIFICATION:

Your post is Beautiful, in its entirety.

I've 'called-myself-to-task', and, while I stand on what I've posted,
elsewhere in the NG, 'agree' that "synchrony implies
cross-correlation.

I'll even admit that, =macroscopically=, there's "oscilation"
in-there. It occurs in the form of convergrnce upon TD E/I(min)
'states' - in which TD E/I traverses, 'back-and-forth', a 'U'-shaped
range of values, until TD E/I(min) occurs.

At more-detalied 'levels', though, there's nothing that's
'steady-state'.

Part of =my= 'problem' is that I use the term "oscilation" to connote
'steady-state' periodicity, and refer to what actually happens within
the 'brain' as [Topologically-Distributed [arrayed]] "damped harmonic
motion". Others use "oscilations" without any explaining the
convergence-mediating "damping" that's =always= in-there. Within the
'brain', the 'damping' is 'just' TD E/I-minimization. When it's
maximized, convergence is maximized. The 'brain' is
relatively-precisely-"tuned", but everything is still 100%-dynamic.
Loop-circuits running-their-relays.

A lot that's in my disagreement derives, mostly, in my 'rebellion'
against the oft-occurring 'band-wagon' stuff in which
relatively-small subsets of what goes on in the nervous system are
held to 'determine-everything', when =everything= in the nervous
system is responsible. My 'rebellion' is with respect to the way
folks 'ignore' great-gobs of what actually underpins this or that
that they're attributing to a small-'subset'. The rest of my 'angst'
with respect to the way "oscillations" are invoked is related, but
has to do with the way folks 'equate' this or that 'subset' stuff
[ie. "oscillation"] with "Eureka!", without explaining all that
underpins the formation of "oscilations" [as above].

Just, "Oscillations!", and "that's the end" of having to explain
anything else.

Doing so is like, if an alien came to Earth, picked up a
capacitive-discharg ignition circuit, and called it a "car".

The other thing is that all of what's in the "oscillations" stuff,
and much-more, has been reified in AoK for the better part of two
decades. Yet, although, such hasn't been acknowledged [I've never
encountered a footnote, for instance], it's been flat-out Obvious,
for decades, that it's NDT that underpins convergence within all of
Neuroscience.

So, when I encounter stuff like this "oscillations" stuff there's the
appearance of its 'gist' having been 'borrowed' from the work I've
done, and its having been 'gussied-up' with 'fancy' nomenclature, and
'experiment', so that the same thing that's been in NDT all along
'can be said', without crediting the work I've done.

Of course, this Assertion is gravely-serious, but it's what has
underpinned my Choice to seek a hearing in some small group, and it's
what has underpinned the fact that I've pretty-much refrained from
public discussion of experimental results.

Since a couple of years after beginning to work online, I've gone,
time after time, to collect papers in the Neuroscience stacks, to
collect refs for discussion in this or that online 'place'. I did so
the other day. But I've always refrained from discussing refs I
select because my trips to the Library have become
increasingly-'heart'-breaking.

Like the other day. I didn't do any searches. I just went to the
Neuroscience stacks, picked-up two issues of one Journal, and found
50 pages of stuff that was all reified, and discussed in AoK, all
along.

It's been like this for nearly two decades.

So, since, if I discuss such refs online, what's going-on will be
obvious to everyone, not wanting to provoke 'scandal', I've refrained
from discussing refs.

And I get-'hammered' for wanting to 'hold the door open' to folks.

And it's seemed that no one will meet with me in-person because folks
know what's going on, and are co-operating within such.

With respect to myself, such 'hurts', but I can
'take-it-on-the-chin'. I did the work of my own volition, after all.

But how can I not CryOut! on behalf of the folks who Siffer-Greatly
be-cause NDT's understanding has been actively withheld from them,
even as it has so obviously been 'borrowed' by folks operating under
the 'publish-or-perish' 'Gun'?

And, what's really awful, is that I can See-Right-Through all the
'obfuscation' that's been heaped-up against the possibility of
Lay-folks' understanding what's been going-on.

So, I've said it.

If anyone demands that I Verify what's here, I will, in-person,
before Fair Witnesses, in a place nearby a good Neuroscience Library.

'Lock the doors', nobody leaves until the dust settles.

K. P. Collins

>
>While what's being referred to as 'synchrony' does reflect
>'cross-correlation' with respect to activation [of course], it
>doesn't reflect anything with respect to specific
>information-content, so 'synchrony' says nothing about 'percept'
>other than the trivial fact that, yeah, 'thought' happens.
>
>In the future, as monitoring techniques continue to become
>more-precise, folks'll see that everything is, in fact,
asynchronous,
>fleetingly-dynamic, energy-flow gradients.
>
>My 'point' is subtle, and I don't expect anyone to agree, but the
way
>that 'oscillations' have come to be routinely invoked makes me want
>to 'throw-up', because of the 'herd-mentality' inherent, and the way
>it gives short-shrift to almost all of what's in the functional
>Neuroanatomy.
>
>It's been a 'pet-peeve' of mine. I'm Sorry  that such has
>'rubbed'-against you.
>
>Cheers, k. p. collins
>
>Matt Jones wrote in message ...
>>mats_trash at hotmail.com (mat) wrote in message
>news:<43525ce3.0207240235.5989ab74 at posting.google.com>...
>>> Im  reading around the literature on nerual oscillations given
the
>>> current vogue for explaining many aspects of function (binding
>>> problem, consciousness) through them.  However, I'm a little
>confused
>>> as to what is actually referred to by 'oscillation' (i.e. what is
>>> oscillating?).  Is it the fluctuation of resting membrane
>potentials
>>> or is it more about the sequential firing of spatially
distributed
>at
>>> certain frequencies.  i.e. given neurons A, B Is the oscillation
>>> A-B-A-B-A-B
>>>
>>> Cheers for any explanations or refs to that effect.
>>
>>
>>Hi mats,
>>
>>When people talk about oscillations in the brain, they essentially
>>mean rhythmic activity that can be detected at the EEG level. The
>EEG
>>(electroencephalogram) works by recording synchronous activity
>across
>>fairly large populations of neurons.
>>
>>As you know, neural electrical activity is comprised of changes in
>the
>>membrane conductance of individual neurons. When ion channels open
>>(e.g., during synaptic transmission or during an action potential),
>>current flows across the membrane. This has two related effects: 1)
>it
>>changes the cells membrane potential, and 2) it causes a small
>change
>>in the distribution of charges inside and outside the cell.  If you
>>perform a "single unit" recording in a living animal, what you are
>>doing is placing a small wire -outside- a neuron. Since you're
>>outside, you can't see small changes in membrane potential the way
>you
>>could if you were making an intracellular recording. But you -can-
>>detect the small change in extracellular charge distribution that
>>occurs when the neuron fires a spike. This is because during a
>spike,
>>a truly huge number of ion channels are doing the same thing all at
>>the same time. The tiny local effects of each channel all sum up
>>together to give a just-barely-detectable change in the
>extracellular
>>charge. This change in charge results in a small, quick change in
>the
>>local voltage, and if your electrode is near enough (i.e., a few
>>microns), you can measure it.
>>
>>However, the small local voltage change from a single cell, even
>>during a spike, is too small to be seen with the EEG, which is
>usually
>>an array of electrodes farther away in the tissue, or most often,
at
>>the surface of the scalp. But if you can get -many- neurons to fire
>>spikes at the same time, then the local extracellular potentials
all
>>add up together, and you can detect it. This change in potential
>from
>>many synchronous individual neurons goes by many names: local field
>>potential (LFP), event-related potential (ERP), or
>>electroencephalogram (EEG).  The core idea is that you are
recording
>>simultaneous (but not necesserily rhythmic) activity from many
>cells,
>>usually hundreds, thousands, or millions in the case of the scalp
>EEG.
>>
>>
>>Now, oscillations:  During many different behaviors, it turns out
>that
>>the EEG does in fact display some rhythmic behavior. That is, if
you
>>look at it, you can actually see repeating wiggles at certain
>>frequencies. In practice, you would take the wiggly signal and pass
>it
>>through a spectrum analyzer or FFT, and note where the peaks
>occurred.
>>For example, during exploration in rats, the EEG recorded near the
>>hippocampus develops a prominent peak around 4-14 Hz (so called
>theta
>>rhythm). During certain other behaviors (usually involving that
>>"binding" thingy), the prominent rhythm in various parts of cortex
>is
>>around 20-80 Hz (so called gamma rhythm). There's a bunch of other
>>greek letter rhythms too, but I forget when and where they occur.
>>
>>What these rhythms signify is that lots and lots of neurons are
>doing
>>whatever they're doing in a roughly synchronous concerted manner.
>THIS
>>DOES NOT MEAN THAT EVERY NEURON IS FIRING AT 20 Hz !!!!  In fact,
>I'm
>>pretty sure that what EEG, ERP and LFP are most often measuring is
>>-not- spike firing, but rather the slower subthreshold potentials
>>associated with synaptic potentials. In a "single-unit" recording,
>you
>>can also see these synaptic potentials from large numbers of cells,
>>but typically one is interested in the spikes, so one high-pass
>>filters out anything slower than spikes. It is possible to get both
>>the spike infrmation and the LFP information by passing the same
>>signal throu two different filters.
>>
>>OK, so that's what people -really- mean when they talk about
>>oscillations. But nowadays, people are always talking about
>>synchronous spiking in the same way that they talk about
>oscillations,
>>so what's up with that?  Well it turns out that you can try and
>>determine whether two neurons (possibly in different regions of the
>>brain) are participating in oscillations with the same frequency
and
>>phase, by analyzing the crosscorrelation between their spiketrains.
>>The idea is that if the two spike trains are crosscorrelated with
>each
>>other, one way of getting such a crosscorrelation (xcorr) would be
>if
>>they were both firing spikes at approximately the same times. This
>>shows up as a peak near zero milliseconds in the xcorr.  If you see
>>such a peak, you might be tempted to shout from the rooftops that
>>these two cells were spiking together, and since one is in the
>>auditory system and the other one is in the visual system (for
>>example), you might conclude that they were both encoding part of
>the
>>same complex "percept" (e.g., the sound of screeching tires and the
>>image of a rapidly approaching truck). This is the idea behind the
>>whole business of synchrony, oscillations, and the "binding"
thingy.
>>
>>And maybe this is indeed what's going on.
>>
>>However, there are also other possibilities. For example, there are
>>other ways of getting two spiketrains to be correlated besides
>>synchronizing the spikes between two neurons. One way is to simply
>>have both neurons -start- firing at the same time, but fire each
>spike
>>randomly (i.e., correlated latency, without synchrony). Another way
>is
>>to have both neurons fire at random times but have their mean spike
>>rates be correlated. So crosscorrelataion does not imply synchrony
>>(which is in fact the title of a very nice paper on the subject by
>>Carlos Brody - do a medline search on him for more info on the
these
>>issues). On the other hand, I believe synchrony -does- strongly
>imply
>>crosscorrelation.
>>
>>Cheers,
>>
>>Matt
>
>





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