[Eeglablist] Is this what we see in the EEG?

[Makoto Miyakoshi]

Hi Yevgeny,

> when the Tsar ordered Dmitri Mendeleev to discover the secret of French
smokeless powder, he examined the factory dump.

I like that.
Let's use this example. Now, imagine that Dmitri uses a stethoscope to hear
the sound of the factory instead of examining the factory dump. This
hypothetical example, which is a poor choice and more challenging, may be
closer to the situation of scalp EEG measurements. Instead of getting
quantitative and qualitative information of chemical compounds used, he
would learn temporal dynamics of the manufacturing process and types of it
by performing time-frequency analysis, etc.. With a microphone array
attached to the factory wall and roof, he may be able to estimate locations
of different types of processing machines and their sizes. But he would
never know the precise ratio of ingredients, processing temperature, etc..
Most importantly, some processes that make little noise would be
transparent to his measurement such as electrolysis.

My point is that God did not create EEG as an official window to study the
brain. Instead, we hack the brain's hypothetically epiphenomenal byproduct
to estimate its function. Thus, there is no guarantee on what brain
functions can measure: spatial distribution of EEG's sensitivity is uneven,
unlike BOLD signals. Hence we cannot use Gaussian random field theory in
inferential statistics.

Another analogy that may be interesting and useful is that EEG research is
more like open-source intelligence (OSINT) than signal intelligence
(SIGINT). OSINT is basically data mining on open information. In contrast,
molecular biology is an example of biological SIGINT because it deals with
the DNA's (de)coding principle.

Makoto


On Tue, May 19, 2026 at 4:11 AM Евгений Машеров <emasherov at yandex.ru> wrote:

>
>
> > Hi Yevgeny and Jack,
> >
> >> True brain activity manifests itself in the higher frequency range and
> >
> > over a very broad frequency band (which corresponds to the conclusions of
> > information theory regarding bandwidth and information transmission
> > intensity).
> >
> > Mathematics captured the universe, but did information theory so too?
> There
> > seems to be different types (definitions) of information than that in
> > Shannon's sense. People talk about brain's interregional 'connectivity'
> by
> > showing phase coherence etc., but has anyone proven what is communicated
> > between the regions? What is the principle of brain's calculation?
> >
> > I even think these questions are perhaps wrong in Wittgenstein's sense.
> >
> > Another random skepticism: Electric fields in the extracellular space is
> > mostly epiphenomenal in the sense that they do not carry any functions
> (an
> > exception is ephaptic coupling, which occurs in much smaller
> > spatial scale). Am I correct? I always think that measuring EEG to
> estimate
> > brain's state is like using a stethoscope to diagnose a car engine. A car
> > engine makes noise, but its purpose is to drive a car. If this is the
> case,
> > then how can we be so sure that critical information must be, and always,
> > contained in the signal? In fact, we already know that scalp
> > EEG's sensitivity to various brain functions and states are patchy.
> >
> Information is what can change our actions. Shannon's definition, through
> probability, is simply a way to make measurable what is intuitively
> estimable. In this case, it's a way to poorly measure something that can't
> be measured otherwise. Clearly, any analogies with technology are
> imprecise, but nevertheless, similar problems sometimes generate similar
> solutions.
> It seems to me that electric fields are secondary to ionic concentration
> (I'd say "epiphenomenon," but I'm afraid to confuse epileptologists). And
> in this sense, changes in the field at one point can be related to the
> field at another, albeit indirectly. As for the analogy with listening to
> the knock of an engine to detect a malfunction, that's a good one, but I
> can offer another: when the Tsar ordered Dmitri Mendeleev to discover the
> secret of French smokeless powder, he examined the factory dump.
>
> Eugen Masherov
>