<div dir="ltr"><div>Thank you for your response. However, I believe and am almost sure that it is not related to the data (P.S. it is from an open EEGdateset which has already been published). By the way, I also tried to perform fastica in EEGlab toolbox and attach the result of it as well. Red line represents after ica, and I put 2 rectangles to show the differences. Is it normal or not? <br></div><div><br></div><div>Moreover, I repeat my second question "
Also I wonder one more thing, what is the mission of cfg.updatesens parameter in ft_ componentanalysis function?
"</div><div><br></div><div>many thanks again</div><div><br></div><div>Elif<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Aug 5, 2022 at 2:12 PM Tineke Grent-'T-Jong via fieldtrip <<a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">I feel something might be wrong with your input data. It is very unlikely that an eyeblink shows up with a similar amplitude across all channels. Typically, it has a topographic distribution, with smaller amplitudes the further away from the source, in this case the eyes.<br>
<br>
Hope this helps,<br>
Best wishes,<br>
Tineke Grent-'t-Jong<br>
<br>
-----Original Message-----<br>
From: fieldtrip <<a href="mailto:fieldtrip-bounces@science.ru.nl" target="_blank">fieldtrip-bounces@science.ru.nl</a>> On Behalf Of <a href="mailto:fieldtrip-request@science.ru.nl" target="_blank">fieldtrip-request@science.ru.nl</a><br>
Sent: Freitag, 5. August 2022 12:35<br>
To: <a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a><br>
Subject: fieldtrip Digest, Vol 141, Issue 4<br>
<br>
Send fieldtrip mailing list submissions to<br>
<a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a><br>
<br>
To subscribe or unsubscribe via the World Wide Web, visit<br>
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" rel="noreferrer" target="_blank">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
or, via email, send a message with subject or body 'help' to<br>
<a href="mailto:fieldtrip-request@science.ru.nl" target="_blank">fieldtrip-request@science.ru.nl</a><br>
<br>
You can reach the person managing the list at<br>
<a href="mailto:fieldtrip-owner@science.ru.nl" target="_blank">fieldtrip-owner@science.ru.nl</a><br>
<br>
When replying, please edit your Subject line so it is more specific than "Re: Contents of fieldtrip digest..."<br>
<br>
<br>
Today's Topics:<br>
<br>
1. Why does applying fastica change the form of EEG data?<br>
(Elif Tülay)<br>
<br>
<br>
----------------------------------------------------------------------<br>
<br>
Message: 1<br>
Date: Fri, 5 Aug 2022 13:34:50 +0300<br>
From: Elif Tülay <<a href="mailto:e.eliftulay@gmail.com" target="_blank">e.eliftulay@gmail.com</a>><br>
To: FieldTrip discussion list <<a href="mailto:fieldtrip@science.ru.nl" target="_blank">fieldtrip@science.ru.nl</a>><br>
Subject: [FieldTrip] Why does applying fastica change the form of EEG<br>
data?<br>
Message-ID:<br>
<CALtq08VJsc_qb2dm+cPSA=<a href="mailto:zKhW_sphCXDgEbe7ws7y5R8Yeh-g@mail.gmail.com" target="_blank">zKhW_sphCXDgEbe7ws7y5R8Yeh-g@mail.gmail.com</a>><br>
Content-Type: text/plain; charset="utf-8"<br>
<br>
Dear Fieldtrippers,<br>
<br>
Now, I work on EEG data which is exported from EEGlab as segmented data. I try to remove eye blinks from the data and I wonder something about ft_componentanalysis function. When I performed fastica to remove the eye blink component, I realized that it changes the form of EEG in addition to removing the related component (please see the attached files, before and after; scales are the same). I cannot understand the reason. It is not because demean application, I checked it.<br>
<br>
Do you have any other idea? By the way, I used averaged referencing on EEGlab. Also please find the script that I used below.<br>
<br>
<br>
<br>
cfg = [];<br>
<br>
cfg.method = 'fastica';<br>
<br>
cfg.channel = {'all', '-VEOG'};<br>
<br>
comp = ft_componentanalysis(cfg, data);<br>
<br>
<br>
<br>
cfg = [];<br>
<br>
cfg.component = [5];<br>
<br>
data = ft_rejectcomponent(cfg, comp, data)<br>
<br>
<br>
<br>
Also I wonder one more thing, what is the mission of cfg.updatesens parameter in ft_ componentanalysis function?<br>
<br>
<br>
<br>
Many thanks in advance,<br>
Elif<br>
-------------- next part --------------<br>
An HTML attachment was scrubbed...<br>
URL: <<a href="http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment.htm" rel="noreferrer" target="_blank">http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment.htm</a>><br>
-------------- next part --------------<br>
A non-text attachment was scrubbed...<br>
Name: after_fastica.jpg<br>
Type: image/jpeg<br>
Size: 174680 bytes<br>
Desc: not available<br>
URL: <<a href="http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment.jpg" rel="noreferrer" target="_blank">http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment.jpg</a>><br>
-------------- next part --------------<br>
A non-text attachment was scrubbed...<br>
Name: before_fastica.jpg<br>
Type: image/jpeg<br>
Size: 179226 bytes<br>
Desc: not available<br>
URL: <<a href="http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment-0001.jpg" rel="noreferrer" target="_blank">http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20220805/86a934ed/attachment-0001.jpg</a>><br>
<br>
------------------------------<br>
<br>
Subject: Digest Footer<br>
<br>
_______________________________________________<br>
fieldtrip mailing list<br>
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" rel="noreferrer" target="_blank">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
_______________________________________________<br>
fieldtrip mailing list<br>
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" rel="noreferrer" target="_blank">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
<a href="https://doi.org/10.1371/journal.pcbi.1002202" rel="noreferrer" target="_blank">https://doi.org/10.1371/journal.pcbi.1002202</a><br>
<br>
<br>
------------------------------<br>
<br>
End of fieldtrip Digest, Vol 141, Issue 4<br>
*****************************************<br>
<br>
_______________________________________________<br>
fieldtrip mailing list<br>
<a href="https://mailman.science.ru.nl/mailman/listinfo/fieldtrip" rel="noreferrer" target="_blank">https://mailman.science.ru.nl/mailman/listinfo/fieldtrip</a><br>
<a href="https://doi.org/10.1371/journal.pcbi.1002202" rel="noreferrer" target="_blank">https://doi.org/10.1371/journal.pcbi.1002202</a><br>
</blockquote></div>