[FieldTrip] Comparing ICA methods between toolboxes (BESA vs. Fieldtrip)

Fri Jan 29 04:25:47 CET 2016

Hi Harald,

I did the ICA based on the continuos recorded block (~7 minutes), including
100 trials, with PCA option on. The attached file is the ICA topography and
waveform (ICA 22). The spectrum showed that the peak power was at ~11Hz.
I suspected it is a neck movement artifact, because the generator seems to
be in the front of the neck. Also, I got another similar ICA component from
another subject, and the topography seems to be centered at the back of the
neck, would it be considered as neck movement too.

Thank you very much once again!

Best,
Andrew

On Mon, Jan 18, 2016 at 7:49 AM, Harald Bornfleth <Harald.Bornfleth at besa.de>
wrote:

> Dear Andrew,
>
>
>
> A couple of questions popped up.
>
> 1)      The neck movement artifact, is this something with low frequency,
> or is it a muscle artifact?
>
> 2)      Did you calculate the ICA on one data screen (e.g. 10 seconds or
> 20 seconds), or over the whole data set?
>
>
>
> If you could send us screen shots showing the ICA wave forms and the
> accompanying topographies, then we could comment on the classification. (In
> BESA, you right-click on the label of a component and select “Map
> topography” to show the topography map of that component.)
>
> I include my colleague and ICA expert Nicole Ille on CC.
>
>
>
> Best regards,
>
> Harald
>
>
>
>
>
> *From:* c.andrew123 at gmail.com [mailto:c.andrew123 at gmail.com] *On Behalf
> Of *Andrew Chang
> *Sent:* 17 January 2016 19:57
> *To:* Harald.Bornfleth at besa.de; FieldTrip discussion list <
> fieldtrip at science.ru.nl>
> *Subject:* Re: [FieldTrip] Comparing ICA methods between toolboxes (BESA
> vs. Fieldtrip)
>
>
>
> Hi Dr. Bornfleth,
>
>
>
> Thanks for your reply very much.
>
> I would like to use ICA to remove eye blinks and eye movements, neck
> movements, as well as cardiac and powerline artifacts. The segment I have
> is a continuous EEG recording for 10 minutes, which is one block of my
> experiment including many trials.
>
> Before ICA, the segment have been high-pass (0.3 Hz) and low-pass (100
> Hz). The components showing activities around the eyes, the back of the
> neck, and 60 Hz were removed. As for the cardiac artifact, I it is based on
> visual inspection on the waveform to see whether it looks like an EKG.
>
> Any further comments are appreciated!
>
>
>
> Best,
>
> Andrew
>
>
>
> On Fri, Jan 15, 2016 at 8:35 AM, Harald Bornfleth <
> Harald.Bornfleth at besa.de> wrote:
>
> Dear Andrew,
>
>
>
> Thanks for bringing this up. I can try to shed some light on the ICA
> method used in BESA Research; however, I can not comment on the
> implementation in FieldTrip.
>
>
>
> The method behind ICA analysis in BESA Research is the extended infomax
> ICA algorithm (Lee TW et al.: Independent component analysis using an
> extended infomax algorithm for mixed sub-Gaussian and super-Gaussian
> sources. Neural Computation 11(2), 1999, 409-433). This algorithm is very
> well suited to remove cardiac and powerline artifacts.  Depending on the
> data, it may also be used to remove ocular (blink) and electrode artifacts.
> To assess whether your artifact removal is trustworthy more information
> about your processing steps are needed. What types of artifacts are you
> trying to correct? What segments are you using to determine the artifact
> topographies and what segments are you finally correcting?
>
>
>
> Best regards,
>
> Harald
>
>
>
>
>
> *Dr. Harald Bornfleth*
>
> Product Manager BESA Research
>
>
>
> *BESA GmbH*
>
> Freihamer Strasse 18
>
> 82166 Graefelfing/Germany
>
> http://www.besa.de
>
>
>
> E: Harald.Bornfleth at besa.de
>
> T: +49 89 8980 9968
>
>
>
>
>
> HRB Munich 109956
>
> CEO: Dr. Tobias Scherg, CFO: Theodor Scherg
>
> Director of Research: Dr. Michael Scherg
>
>
>
>
>
>
>
>
>
>
>
>
>
> *From:* fieldtrip-bounces at science.ru.nl [
> mailto:fieldtrip-bounces at science.ru.nl <fieldtrip-bounces at science.ru.nl>] *On
> Behalf Of *Andrew Chang
> *Sent:* Sonntag, 10. Januar 2016 21:18
> *To:* fieldtrip at science.ru.nl
> *Subject:* [FieldTrip] Comparing ICA methods between toolboxes (BESA vs.
> Fieldtrip)
>
>
>
> Dear Fieldtrip users,
>
>
>
> I am wondering whether anyone has compared the performances of the ICA
> methods among M/EEG toolboxes. Especially, how is the performance of ICA in
> BESA Research 6.0, compared to Fieldtrip?
>
> I have an EEG data set which has been processed in BESA, including
> removing artifact using ICA. I am wondering whether I can trust it, or
> I should reprocess it in Fieldtrip. Any comments will be appreciated!
>
>
>
> Happy new year!
>
>
>
> Best,
>
> Andrew
>
>
>
> --
>
> Andrew Chang
> Ph.D. Candidate
> Auditory Development Lab
>
> Department of Psychology, Neuroscience & Behaviour
> McMaster University
>
> http://changa5.wordpress.com/
>
>
> _______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>
>
>
>
>
> --
>
> Andrew Chang
> Ph.D. Candidate
> Auditory Development Lab
>
> Department of Psychology, Neuroscience & Behaviour
> McMaster University
>
> http://changa5.wordpress.com/
>

-- 
Andrew Chang
Ph.D. Candidate
Auditory Development Lab
Department of Psychology, Neuroscience & Behaviour
McMaster University
http://changa5.wordpress.com/
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