[Eeglablist] Artifact removal using ADJUST plugin (Rabnawaz khan)
13mseerabnawaz at seecs.edu.pk
Fri Apr 28 22:13:24 PDT 2017
Thank you for your response.
After plotting my data using EEGlab plot (scroll plot option), I can see
some portion of my data is very noisy, most of the channels are giving huge
peaks for some duration (I am not sure how to differentiate these noise but
I can guess these are not the eye or muscle artefacts). Moreover, I am
using Emotiv EPOC headset for recordings, which is 14 channels data, and
the duration of my recordings is 180sec.
any good advice dealing with it?
On Wed, Apr 26, 2017 at 4:49 PM, Armand Mensen <research.mensen at gmail.com>
> Dear Rabnawaz,
> A few things here to comment on.
> 1) I think you may be expecting too much from any automatic artefact
> removal (or manual ones for that matter). Which sorts of artefacts any tool
> can remove from your data may depend on a multitude of factors. For
> example, ICA is generally quite good at finding eye blinks and eye
> movements. However even there it depends on the number of channels you
> recorded, and the length of your recording time, whether those sorts of
> artefacts can be removed without taking too much good data with them. So
> what sort of artefacts are you trying to deal with? How many channels do
> you have? How long is your recording?
> 2) It is generally unwise to run multiple ICA analysis one after another.
> There are a couple of reasons for this, but the main one (I think) is that
> you are reducing the rank of your data each run. This rank reduction is not
> always so easily or accurately detectable and will lead to problems.
> 3) I've used ADJUST sparingly in the past, and wasn't overly impressed.
> While examining components manually does take longer than just running some
> automatic script... you will get a good feeling for the quality of your
> data as well as the sorts of strong independent sources that are there
> (whether artefactual or not). I completely see the utility of using the
> same artefact criteria and taking some of the subjective decision making
> out of using ICA to remove artefacts... however only to the extent that
> these standard criteria are really generalisable, and useful in the first
> place [apologies to any ADJUST creator or enthusiast; I'd be happy to be
> convinced otherwise].
> Good luck with your analysis!
>> ---------- Forwarded message ----------
>> From: Rabnawaz khan <13mseerabnawaz at seecs.edu.pk>
>> To: eeglablist at sccn.ucsd.edu
>> Date: Tue, 25 Apr 2017 18:34:43 +0800
>> Subject: [Eeglablist] Artifact removal using ADJUST plugin
>> Dear All,
>> I am using ADJUST plugin for artifact removal from raw data. I follow the
>> instruction listed in the ADJUST manual to process the data. after running
>> ADJUST I get the artifacted ICs in a new pop-up window, I mark these ICs
>> for rejection and then I go to tools to remove these ICs (via EEGlab GUI
>> menu>>tools>>remove components). A new dataset is created (eegdata pruned
>> with ICA ), according to ADJUST tutorial this is the clean eeg data, but I
>> see from the plots that there is still artifact present in the data. When I
>> run ICA again and then again run ADJUST I get a new pop-up window in which
>> some other ICs are identified as artifacts. I remove these ICs again. But
>> still, artifact are present in data. I repeat running ADUST many time and
>> each time I get new ICs marked as an artifact.
>> I would be happy if you guide me with this problem.
>> Best Regards,
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