[Eeglablist] microstate analysis

[Maruti Mishra]

I am interested in knowing this as well. I recently found a special issue,
but would really like to know the current trends and views here.
https://urldefense.com/v3/__https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10884048/__;!!Mih3wA!H1GphCJroPky7TZ5pBsvM8CF05xy2TlkptVyjq0lAYXqUGfdBThslpNuWZsktWpPT8ld_w1pqRNXrFFwZ-ZBDmh3-xbLVPw$ 

Thank You,
Maruti


On Mon, May 6, 2024 at 10:54 AM Kevin Spencer via eeglablist <
eeglablist at sccn.ucsd.edu> wrote:

> Hello EEGers,
>
> Another couple of posts brought up the issue of microstate analysis, which
> has been bothering me recently. I'm not sure if I'm missing something, but
> the basic approach with ERPs, clustering topographies across the epoch into
> discrete "states", seems to ignore the well-established fact that the
> topography of the EEG across the scalp at a given time point represents the
> sum of numerous spatially and temporally overlapping activity patterns.
> That's why people originally applied PCA to ERP data, to disentangle these
> overlapping patterns. A classic example is that the "late positive complex"
> consists of several ERP components that overlap each other in time and
> space (e.g., P3a, P3b, classic Slow Wave, etc.).
>
> If you apply some type of cluster analysis to the topographies of epochs
> of EEG single trials or ERPs, you are going to get clusters that represent
> maxima in global field power, but which say nothing about the multiplicity
> of activity patterns that contribute to these clusters. In contrast, if you
> apply say ICA to the data, you decompose the data into distinct activity
> patterns that do overlap in various dimensions. So I don't see what is so
> useful about microstate analysis. But perhaps I'm missing something. I'd be
> interested in what people who know this method better than I do have to say.
>
> There is also the whole issue of what a brain "state" is. I'm not aware of
> any reason to think that a scalp topography that lasts for X ms constitutes
> a brain state. But again, maybe I'm not aware of research that supports
> this idea.
>
> Kevin
>
>
> ---------------------------------------------------------------------------------
> Kevin M. Spencer, Ph.D.
> Research Health Scientist, VA Boston Healthcare System
> Associate Professor of Psychiatry, Harvard Medical School
>
> ---------------------------------------------------------------------------------
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>