[Eeglablist] Topic discussion (July 2022) [1]

[Makoto Miyakoshi]

So far I have two requests received for the discussion:

   - Physiological interpretation of ICA
   - How the kHz activity in the action potential becomes Hz range in the
   scalp-recorded EEG

Let me start with the first point. Note that of course this is my personal
view.

%%%%%%%%%%%%%%%%%%%%%%%%
%%% Physiological interpretation of ICA %%%
%%%%%%%%%%%%%%%%%%%%%%%%
What I call 'physiological interpretation of ICA' is basically what Scott
established between mid 90's (Makeig, Jung, Bell, Sejnowski., 1996) to mid
2000's (Onton and Makeig, 2006). The core claim of this dogma is the
following:

ICA results can be directly interpreted as physiologically valid
'effective' EEG sources

This sounds almost too good to be true for most of the seasoned
neuroscientists. But he strived to prove it, and I believe it turned out
pretty successful. He devised unique concepts, such as dipolarity,
independence-dipolarity identity (IDID; I named it), the correlation
between dipolarity and mutual information reduction (Delorme et al., 2012),
etc.. He also repeatedly demonstrated that using the ICA-obtained spatial
filter, one can also decompose time-domain activities, for which he
invented percent-variance accounted for (PVAF) used in envtopo analysis
(Lee et al., 2015). The success in the initial launching of the concept
'physiological interpretation of ICA' also overlaps with the most prolific
publication records of SCCN as well, which were often first-authored by
Scott himself. If I select the ICA-EEG papers from SCCN published from
high-impact-factor journals during this period, I can count PNAS (1997),
Philosophical Transactions of the Royal Society B (1999), Science (2002),
Trends in Neuroscience (2002), PLoS Biology (2004), Trends in Cognitive
Science (2004), J Neurosci (1999; 2007), NeuroImage (2005, 2007), etc etc.
And of course, his ICA-centric approach prevailed with the huge success of
EEGLAB (Delorme and Makeig, 2004). I personally believe that the pinnacle
of his 'physiological interpretaion of ICA' can be found in Onton and
Makeig (2006) so I always recommend it to those who are interested in 'why
ICA' . Makeig and Onton (2011) is also a good summary but this was
published much later. So is Delorme et al. (2012)--maybe this is the last
and the final piece of the paper dedicated for ICA's physiological
interpretation.

(Continued--if you have any questions, please post it. By the way, I have a
grant deadline next week. I'll continue it after the deadline.)

Makoto

On Mon, Jul 4, 2022 at 10:17 AM Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
wrote:

> Dear eeglab mailing list subscribers,
>
> I will answer the questions on the list in July.
> There is also a request that I should start a topic discussion for this
> month. Personally, I would be interested in discuss either:
>
>    - Physiological interpretation of ICA (small vs. large patch
>    hypotheses, frequency dependency of independence, why IC rejection always
>    increases gamma power, etc.)
>    - EEG's global theory (traveling and standing waves of synaptic action
>    density field, etc.)
>    - Anything that are discussed here:
>    https://sccn.ucsd.edu/wiki/Makoto's_preprocessing_pipeline#Special_contents_since_100.2C000_page_views
>
> If you are interested, please vote. If no vote, I'll pick up random topic
> for each time.
>
> Makoto
>