[Eeglablist] EEGLAB Orientation

Fri Dec 6 07:11:11 PST 2024

Hi Joe,

Thank you for your valuable input. I definitely agree with you, based on my
non-systematic observations too.

It is good to learn that the developers of robust ANOVAs recommended 20%
trimming and your recommendation of 5% trimming.

I think there is a psychological factor here; how much robustness one
requires reflects how deeply traumatized one is from past experiences of
EEG processing. I tend to be on the side of safety, and I have published
EEG datasets recorded from subjects walking around mazes, ticing patients,
and performance of three-ball juggling (in prep), repeated lifting of a
heavy box (in prep), etc. If I know my data are from laboratory recordings,
I would definitely use 5% trimming.

Makoto

On Thu, Dec 5, 2024 at 5:57 PM Joseph Dien via eeglablist <
eeglablist at sccn.ucsd.edu> wrote:

> I think it's an empirical question.  If you're using a median, you are
> in effect relying on a single data point (albeit a median one) and it
> will have some amount of noise too.  The question then is whether the
> noise you throw out with the rest of the points outweighs the signal
> that you throw out with the rest of the points.  Or to put it another
> way, median is a great way to eliminate high amplitude noise, but not
> necessarily low amplitude noise.  A graphic example that comes from my
> non-systematic observations of median averaging for ERPs (using my EP
> Toolkit), at least, is that it can give rise to sharp discontinuities in
> the waveform.  I imagine a similar effect could happen in
> frequency-space.  For robust ANOVAs, the developers (Wilcox, Keselman,
> Lix, Algina, et al) generally also recommend a 20% trim, but after
> mucking around with ERP data (again using my EP Toolkit), I came to the
> conclusion that a modest 5% trim was the better way to go (assuming n>=
> 20).  Still unsystematic, though.
>
> Definitely worth looking at!
>
> Joe
>
>
>
> On 12/5/24 11:30, Makoto Miyakoshi via eeglablist wrote:
> > Hi Cedric,
> >
> > If you decide not to perform any signal processing for so called data
> > cleaning, do you think 20% trimming is trustworthy enough? I know it
> > is an empirical question. But in theory, median's breakdown point is 50%.
> > Since 50%>20%, why not?
> >
> > Cyril once told me that if people assume Gaussian distributions
> everywhere
> > anyway, why not use median? Good point.
> >
> > Makoto
> >
> > On Thu, Nov 28, 2024 at 7:50 AM Cedric Cannard via eeglablist <
> > eeglablist at sccn.ucsd.edu> wrote:
> >
> >>> I have long thought that the averaging process in Welch's method should
> >> be replaced with median because EEG recordings can contain pretty bad
> >> outliers.
> >>
> >> I recommend 20% trimmed mean :)
> >>
> >>
> >> Cedric
> >>
> >>
> >>
> >> On Monday, November 25th, 2024 at 12:25 PM, Makoto Miyakoshi via
> >> eeglablist <eeglablist at sccn.ucsd.edu> wrote:
> >>
> >>> Hi Arno and all
> >>>
> >>> Thanks for your input.
> >>> I recommend people posted here try that plugin and tell me what it
> does.
> >>>
> >>> eegfiltnew() and fir_filt() are close enough, if you just
> >>> need band-specific powers.
> >>>
> >>> Makoto
> >>>
> >>> On Sun, Nov 24, 2024 at 12:43 AM Arnaud Delorme via eeglablist <
> >>> eeglablist at sccn.ucsd.edu> wrote:
> >>>
> >>>> For extracting brainwaves at specific frequencies, I would advise
> using
> >>>> the eegstats EEGLAB plugin.
> >>>>
> >>>> Best wishes,
> >>>>
> >>>> Arno
> >>>>
> >>>>> On Nov 22, 2024, at 22:09, Meha Fatima via eeglablist <
> >>>>> eeglablist at sccn.ucsd.edu> wrote:
> >>>>>
> >>>>> Hi. Thank you for this opportunity. I'd like to join in, too. Can you
> >>>>> please share the Zoom link?
> >>>>>
> >>>>> On Fri, 22 Nov 2024 at 23:34, Makoto Miyakoshi via eeglablist <
> >>>>> eeglablist at sccn.ucsd.edu> wrote:
> >>>>>
> >>>>>> Hi Devvarta,
> >>>>>>
> >>>>>>> Could you please open this zoom session for others as well?
> >>>>>> Sure, gather as many participants as you want and let them ask as
> >> many
> >>>>>> questions as necessary.
> >>>>>> I'll be available after 7:00 am in New York time (EST) which is
> >> 5:30 pm
> >>>>>> in
> >>>>>> Bangalore. I prefer it in the morning rather than the
> >> evening/night.
> >>>>>> I notice that there has been a large and constant need for
> >> extracting
> >>>>>> EEG
> >>>>>> power using EEGLAB, which is only partially supported by GUI.
> >>>>>> After our discussion, maybe I can summarize the requested
> >>>>>> functionalities
> >>>>>> into a solution in the form of EEGLAB plugin. It should be pretty
> >> easy.
> >>>>>> What I want to know is the type of output format you need most. Is
> >> it
> >>>>>> ascii
> >>>>>> or Excel? Do you want a result in linear scale (microV^2) or in
> >> dB? Do
> >>>>>> you
> >>>>>> want a mean power within a frequency band (with SD across sliding
> >>>>>> windows)
> >>>>>> or full freq bin resolution (which is already available in EEGLAB
> >>>>>> spectopo)
> >>>>>> etc..
> >>>>>>
> >>>>>> I like the idea of robust PSD proposed by Melman and Victor (2016)
> >> so
> >>>>>> that
> >>>>>> you do not need to worry too much about data cleaning.
> >>>>
> >>
> https://urldefense.com/v3/__https://pmc.ncbi.nlm.nih.gov/articles/PMC4903894/__;!!Mih3wA!Hc_qvUxHKj94lakBpoAoDLDmyqzks4elWCUSSecAgiLfWsompHx83bc4_GJA8f1FYPh9Rceqb8iycYCC-UFVaSR4uL8$
> >>>>>> I have long thought that the averaging process in Welch's method
> >> should
> >>>>>> be
> >>>>>> replaced with median because EEG recordings can contain pretty bad
> >>>>>> outliers. At least, outcomes from Welch's method by mean and
> >> median can
> >>>>>> be
> >>>>>> compared to evaluate the window-mean PSD's deviation from the
> >>>>>> window-median
> >>>>>> PSD.
> >>>>>>
> >>>>>> Grace, if this selection of time does not work for you, we can set
> >> a
> >>>>>> separate Zoom meeting. Tell me what time zone you are in.
> >>>>>>
> >>>>>> Makoto
> >>>>>>
> >>>>>> On Fri, Nov 22, 2024 at 3:42 AM Devvarta Kumar <
> >>>>>> devvarta.k at nimhans.ac.in>
> >>>>>> wrote:
> >>>>>>
> >>>>>>> Hi Mokoto
> >>>>>>> I assume many of us would be interested in understanding the
> >> process of
> >>>>>>> calculating power in different bands in raw EEG. Could you
> >> please open
> >>>>>>> this
> >>>>>>> zoom session for others as well?
> >>>>>>> Regards
> >>>>>>>
> >>>>>>> Devvarta Kumar, Ph.D.
> >>>>>>>
> >>>>>>> Professor
> >>>>>>> Department of Clinical Psychology
> >>>>>>> M. V. Govindaswamy Building
> >>>>>>> National Institute of Mental Health and Neurosciences,
> >>>>>>> Hosur Road,
> >>>>>>> Bangalore,
> >>>>>>> Karnataka-560029
> >>>>>>> India
> >>>>>>>
> >>>>>>> Ph: +91-80-26995188
> >>>>
> >>
> https://urldefense.com/v3/__http://www.nimhans.ac.in/users/dr-devvarta-kumar__;!!Mih3wA!E8Vsq9Vu8Q4ZAl8UIb5elP9m72UAtG-_h15RsH4N7qURhjnEctf1NKia1NpntFgQlL_UtZbHh_sQjnDjaxBj7B3Oazg$
> >>>>>>> ResearchGate:
> >>>>
> >>
> https://urldefense.com/v3/__https://www.researchgate.net/profile/Devvarta_Kumar/contributions__;!!Mih3wA!E8Vsq9Vu8Q4ZAl8UIb5elP9m72UAtG-_h15RsH4N7qURhjnEctf1NKia1NpntFgQlL_UtZbHh_sQjnDjaxBj8leJO1o$
> >>>>>>> ----- Original Message -----
> >>>>>>> From: eeglablist at sccn.ucsd.edu
> >>>>>>> To: eeglablist at sccn.ucsd.edu
> >>>>>>> Sent: Friday, November 22, 2024 1:51:05 AM
> >>>>>>> Subject: Re: [Eeglablist] EEGLAB Orientation
> >>>>>>>
> >>>>>>> Hi Grace,
> >>>>>>>
> >>>>>>> If your group wants to Zoom with me, I'll be available. Which
> >> time zone
> >>>>>>> are
> >>>>>>> you in?
> >>>>>>>
> >>>>>>> Makoto
> >>>>>>>
> >>>>>>> On Thu, Nov 21, 2024 at 2:50 PM Grace Bang via eeglablist <
> >>>>>>> eeglablist at sccn.ucsd.edu> wrote:
> >>>>>>>
> >>>>>>>> Hello!
> >>>>>>>>
> >>>>>>>> We are 3rd year medical students trying to conduct research
> >> where we
> >>>>>>>> collect brain wave activity data using the CGX Patch 2-channel
> >> EEG.
> >>>>>>>> We've
> >>>>>>>> been having a lot of issues trying to navigate how to use
> >> EEGLAB to
> >>>>>>>> process
> >>>>>>>> the data. We just want to be able to quantify the number of
> >> alpha and
> >>>>>>>> beta
> >>>>>>>> waves present in the raw data. The resources we've read online
> >> have
> >>>>>>>> been
> >>>>>>>> somewhat helpful, but we are looking for someone who can jump
> >> on a
> >>>>>>>> Zoom/phone call to help fill some gaps of knowledge. Neither
> >> of us
> >>>>>>>> have a
> >>>>>>>> background in more complicated softwares/coding/EEGs so any
> >> guidance
> >>>>>>>> would
> >>>>>>>> be greatly appreciated!
> >>>>>>>>
> >>>>>>>> - Grace Bang, OMS-3
> >>>>>>>> _______________________________________________
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> >>>>> --
> >>>>>
> >>>>> * Dr. Meha Fatima BSMT, Ph.D.*
> >>>>> Assistant Professor
> >>>>> Dow Institute of Medical
> >>>>> Technology
> >>>>> Dow University of Health Sciences
> >>>>> mehafatima1 at gmail.com
> >>>>> mehafatima1 at gmail.com.
> >>>>> _______________________________________________
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> --
>
> --------------------------------------------------------------------------------
>
> Joseph Dien, PhD
> Senior Research Scientist
> Department of Human Development and Quantitative Methodology
> University of Maryland, College Park
>
> https://urldefense.com/v3/__http://joedien.com__;!!Mih3wA!EGE2-zRkTBdtoncXH2B0SBkrfuhEPiKTJPw7napVfD_D5-0MyWNtH5yenPuXhv2sO8ypc5xF69eVQxHXlPw$
>
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