[Eeglablist] Source localization and hippocanpus

Thu Feb 5 15:50:51 PST 2026

Hi all,

If we develop an EEG version of this solution, we can answer the question.
https://urldefense.com/v3/__https://www.sciencedirect.com/science/article/abs/pii/S105381190291102X?via*3Dihub__;JQ!!Mih3wA!HwsurlhLmCGSy6wCiD5l9SSb_thJ_sxE8EJlEsKXD0KDFSdVaEdxAC8dST2UIXhjpckQKpFDlX_vA2AqAYmVO9BujEY$ 
Does anyone object to this claim?

Then, why don't we just do it?

That is because---Komal is already working on it. The project code is 'EEG
impossibility atlas'.

Makoto

On Tue, Feb 3, 2026 at 4:22 AM Cedric Cannard via eeglablist <
eeglablist at sccn.ucsd.edu> wrote:

> Yongxian,
>
> Wow… this looks potentially incredibly groundbreaking. If the claims hold
> up to further validation, it could address so many longstanding limitations
> across neuroimaging modalities. Especially the low temporal resolution of
> fMRI and the recent finding by Epp et al (2025) that ~40% of voxels with
> significant BOLD changes showed oxygen metabolism going in the opposite
> direction to what BOLD indicated (decreased CMRO₂).
>
> I’ll be following the replication efforts closely. Thanks for sharing!
>
> Cedric
>
> Sent from Proton Mail for iOS.
>
> -------- Original Message --------
> On Monday, 02/02/26 at 15:51 Qian, Yongxian via eeglablist <
> eeglablist at sccn.ucsd.edu> wrote:
> Dear Eugen and Makoto,
>
> I am very interested in this discussion about the EEG source localization,
> especially at deep brain regions like the hippocanspus.
>
> Accidentally, we just completed a research work about quantum sensing MRI
> (qsMRI) for detection of neuronal electrical activity (
> https://urldefense.com/v3/__https://arxiv.org/pdf/2601.16423__;!!Mih3wA!A5WTWbxQ1Fe5li2NSeeVa9LvVA5-JOIOgdygiOdvNUggK74DYpMfj4VuVR1y50JThTDHm-jp_iZrnUZdrXmd8Yz2ZPcYNUvvSQ$
> ), in which neuronal firing source localization is definitive through MRI
> imaging.
>
> The qsMRI may help you all to clarify some issues regarding the EEG signal
> source localization.
>
> By the way, our group uses an MRI-compitable EEG system (32Ch, Brain
> Vison) to study sleep impact on CSF flow in normal aging population (25 -
> 100 years old).
>
> Best,
>
> Yongxian
>
> ----------------------------------------------------------------------------------------------------
>
> Yongxian Qian, PhD
>
> Assistant Professor, Center for Biomedical Imaging, Department of Radiology
>
> Investigator, Neuroscience Institute, Department of Neuroscience and
> Physiology
>
> Training Faculty, Vilcek Institute of Graduate Biomedical Sciences
>
> NYU Grossman School of Medicine
>
>
> Editorial Board Member, Scientific Reports, a Nature portfolio journal
>
> Guest Editor, "Quantum Technologies for Healthcare", Scientific Reports, a
> Nature portfolio journal
>
> https://urldefense.com/v3/__https://www.nature.com/collections/bebgeadadf/guest-editors__;!!Mih3wA!A5WTWbxQ1Fe5li2NSeeVa9LvVA5-JOIOgdygiOdvNUggK74DYpMfj4VuVR1y50JThTDHm-jp_iZrnUZdrXmd8Yz2ZPfsJw6mfQ$
>
>
> NYU Langone Health
>
> Center for Biomedical Imaging (CBI)
>
> 660 First Avenue, 4th Floor
>
> New York, NY 10016
>
> T: 212-263-1159
>
> Yongxian.Qian at nyulangone.org
>
>
> ----------------------------------------------------------------------------------------------------
>
> ________________________________
> From: eeglablist <eeglablist-bounces at sccn.ucsd.edu> on behalf of Евгений
> Машеров via eeglablist <eeglablist at sccn.ucsd.edu>
> Sent: Saturday, January 31, 2026 7:10 AM
> To: Makoto Miyakoshi <mmiyakoshi at ucsd.edu>
> Cc: EEGLAB List <eeglablist at sccn.ucsd.edu>
> Subject: Re: [Eeglablist] Source localization and hippocanpus
>
> [EXTERNAL]
>
> The question of what source amplitude is required for a signal from deep
> brain regions to be registered on the scalp arose when Professor Olga
> Grindel, then head of the Clinical Neurophysiology Laboratory, suggested I
> study and use the dipole localization method (Yu. M. Koptelov's BraibLoc
> program) for clinical applications. Preliminary calculations showed
> completely non-physiological amplitude values, and I approached the task
> with extreme skepticism. However, not only were deep brain sources detected
> by this method, but they were also confirmed during surgeries. Since I
> didn't want to portray Admiral Nelson putting a telescope to his missing
> eye and declaring "I see nothing," I also didn't like the explanation that
> the signal from deep brain sources travels along neural pathways to the
> cortex and we see the signal from the cortex, as this contradicted the
> entire mathematical apparatus of localization. I tried to find other
> explanations. One of them is monopole sources, the potential from which
> decreases more slowly than from dipole sources. But then it's unclear why
> they are detected by algorithms that implicitly assume dipoles. It's
> possible that we're dealing with a pair of monopoles with opposite signs,
> so a dipole at the point between them provides a good approximation.
> Another explanation is a system of synchronized dipoles along the surface,
> creating a potential that decreases significantly more slowly at distances
> comparable to the size of the surface. Secondary dipoles arising at the
> boundaries of regions of different conductivity may also contribute. It
> seems to me that all of these mechanisms are at work, along with something
> else that's still unclear. Sources of these two types—monopole and
> dipole—as well as quadrupole, operate in all brain structures, but the
> ability to register a signal from them on the scalp depends on the distance
> and orientation of the source, to varying degrees for these three types,
> but also on the synchronization between them. It seems to me (but this
> doesn't even deserve the title of a full-fledged hypothesis, only a
> suggestion) that monopoles are associated with low-frequency activity (but
> not just delta, possibly up to alpha or even slightly higher) and the
> formation of sinusoidal oscillations, and their physiological role is the
> regulation of biochemical processes, in particular metabolism and ion
> concentration levels. Dipoles are a product of neural activity itself,
> EPSPs and IPSPs, while quadrupoles (not recorded from the scalp, except in
> cases of synchronization of groups of sources) are associated with action
> potentials. Perhaps such a complication of the generation model will not
> only clarify the physiology of the brain but also provide a mathematical
> framework more adequate to the problem.
>
> Eugen Masherov
>
> > Hi all,
> >
> > I've read this discussion with great interest!
> > Here are my thoughts.
> >
> > 1. If I adopt a conventional dogma of generative mechanism of EEG i.e.,
> > all/most of scalp-measured EEG signals entirely generated by
> post-synaptic
> > membrane potential in cortical surface (Electric Fields of the Brain,
> EFB,
> > by Nunez and Srinivasan 2006 adopts this assumption, for example),
> > measuring EEG signals generated in the hippocampus using a conventional
> EEG
> > recorder (i.e., sensitivity limit > 1 microV) would be impossible
> primarily
> > because of the geometry (too small, too deep, rolled shape, etc..)
> > 2. However, a modern electrodiffusive neural-extracellular-glia (edNEG)
> > model indicates the possibility that non-synaptic source activity affects
> > scalp EEG as well, which is much less studied. See Saetra et al. (2021)
> for
> > full details (but this one is super technical).
> >
> https://urldefense.com/v3/__https://journals.plos.org/ploscompbiol/article?id=10.1371*journal.pcbi.1008143*libraryItemId=11397962__;LyM!!Mih3wA!HKOkIU0i7obnN2bi48-tFzXvjoC4GDRCU_PNDuM4JjgXO5eU64BD7_JedfcOwGzJ1sa-MaQUQsJcYI8SaWZ6uQfdIgo$
> > 3. I read the dispute between Joseph's group and Mike's group with great
> > interest. If I stand on the conventional viewpoint, I agree with Mike,
> and
> > I usually stand on it. But that does not mean non-conventional source
> > cannot exist, particularly if it is observed in a low-frequency range
> > (below delta). After all, we do not know EEG phenomenon completely, so we
> > are not there yet to make an a priori prediction that can properly bound
> > the observation (i.e., "If we observe X under certain conditions, it MUST
> > BE noise because it cannot be there from biophysics!")
> > 4. That said, I still want to emphasize that learning the conventional
> > synaptic dogma and EEG's unique scaling law (i.e., volume conductor
> theory,
> > including what I call 'transducer array effect' of a dipole layer) is
> very
> > important. For those who are curious, below I provide two sources of
> > information:
> >
> > The first material to read is an excerpt from EFB 2nd ed page 81-83.
> Here,
> > the authors demonstrate a typical misconception/misuse of both equivalent
> > current dipole model and assumption of EEG source distributions (i.e.,
> > small vs. large cortical patches). As a result, such an incorrect
> > application leads to an implicit conclusion that there was a 5V
> (=5,000,000
> > microV) source inside the brain. The authors' following concluding remark
> > suggests there exists this known pitfall/misconception in literature
> > reporting dipole source models in general (ouch...)
> >
> > *Of course, such extracellular potentials are too large by a factor of
> 1000
> > or more to be physiologically realistic. However, such considerations
> have
> > not prevented reports of such magical dipoles. One wonders if this
> explains
> > why source magnitudes are often not reported.*
> >
> >
> https://urldefense.com/v3/__https://drive.google.com/open?id=1LGyydB9ZucbBG9EQoZDKAg4CEUJlAWon__;!!Mih3wA!HKOkIU0i7obnN2bi48-tFzXvjoC4GDRCU_PNDuM4JjgXO5eU64BD7_JedfcOwGzJ1sa-MaQUQsJcYI8SaWZ6jRpcvKE$
> >
> > The second material to read is my manuscript under review, in which I
> > described what I believe is the correct 'scaling law' of scalp-recorded
> EEG
> > signals. Please find the section "Where did the small patch model come
> > from, and what does it miss?" in Discussion.
> >
> >
> https://urldefense.com/v3/__https://www.medrxiv.org/content/10.64898/2026.01.23.26344529v1*libraryItemId=18612094__;Iw!!Mih3wA!HKOkIU0i7obnN2bi48-tFzXvjoC4GDRCU_PNDuM4JjgXO5eU64BD7_JedfcOwGzJ1sa-MaQUQsJcYI8SaWZ6Qhjxqso$
> >
> > I will submit a separate post about this manuscript, as this 'scaling
> law'
> > is a tool for a larger aim.
> >
> > I have one more thing I wanted to report here, which would make a
> practical
> > (and I believe substantial) contribution to this debate. But because
> Komal
> > wants to keep it a low profile until he comes up with some proof of
> > concept, I cannot tell you what it is ha ha. I believe that this solution
> > provides a clear answer to the question "Can EEG measure the hippocampus'
> > at least within the limitation of the conventional synaptic dogma +
> volume
> > conductor theory.
> >
> > Makoto
> > _______________________________________________
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