[Eeglablist] ICA and eye blink component

[Marco Buiatti]

You can use it also BEFORE ICA but with a higher threshold, so that are
sure that you remove very big artifacts and obtain a better ICA
decomposition.

Best,

Marco


On 6 August 2014 10:55, bjj2909102003 <bjj2909102003 at 163.com> wrote:

> Thank you very much, Mr Marco!
> Regard to  EEGLAB's rejection methods, I admit it is thorough. However,
> in cognitive neuroscience research papers  I ofen see "Rejecting extreme
> values" is used and other rejection methods(abnormal trends, improbable
> data and abnormal spectra) were less. And for me, "Rejecting extreme
> values"   is used after rejecting blink with ICA.
>
> ------------------------------
> bjj2909102003
>
>
> *From:* Marco Buiatti <marco.buiatti at gmail.com>
> *Date:* 2014-08-06 16:35
> *To:* bjj2909102003 <bjj2909102003 at 163.com>
> *CC:* eeglablist <eeglablist at sccn.ucsd.edu>
> *Subject:* Re: Re: [Eeglablist] ICA and eye blink component
> Dear Booer,
>
> even though it's time consuming, my advice is:
> - to find a way to reject very noisy segments of data BEFORE applying ICA
> (for example using EEGLAB's rejection methods and tuning the threshold to
> be as good as possible for all your subjects)
> - to review ICA components marked as artefacted by ADJUST or any other
> method you want to use before blindly accepting automatic classifications.
> In my experience, the time spent in cleaning the data is paid back by much
> clearer results in the analysis!
>
> Best,
>
> Marco
>
>
> On 6 August 2014 09:22, bjj2909102003 <bjj2909102003 at 163.com> wrote:
>
>> Thank you for replying.
>> Actually, before I run ICA, I only filter the data by bandpass filter. It
>> takes too much time to reject some non-stereotypical artifacts,
>> especially when I got many subjects(~100) data.
>> It is painful by visual inspection one by one. Your advice is good.
>> Nonetheless, I believe ICA is robust in many situations.
>>
>> Thanks!
>> Booer
>> ------------------------------
>> bjj2909102003
>>
>>
>> *From:* Marco Buiatti <marco.buiatti at gmail.com>
>> *Date:* 2014-08-06 14:53
>> *To:* bjj2909102003 <bjj2909102003 at 163.com>
>> *CC:* eeglablist <eeglablist at sccn.ucsd.edu>
>> *Subject:* Re: [Eeglablist] ICA and eye blink component
>> Dear Booer,
>>
>> blinks are usually well identified by ICA. You may not easily identify
>> blinks if:
>> 1) your subject blinks really a few times -> not enough for being
>> captured by ICA, you may just discard the few epochs containing the blinks;
>> 2) when your subject blinks, s/he moves so much that the relative
>> artifact spreads over most sensors, and ICA is not able to capture it in a
>> few clear components  -> Also in this case my advice is to  discard the
>> epochs containing the blinks;
>> 3) you are computing the ICA on noisy data -> reject segments of your
>> data containing non-stereotypical artifacts and compute the ICA again.
>>
>> ADJUST works well only if the ICA is computed on clean enough data.
>>
>> Refs:
>> On blinks: Croft, R., & Barry, R. (2000). Removal of ocular artifact from
>> the EEG: A review. Clinical Neurophysiology, 30, 5–19.
>>
>> On removing blinks with ICA:  Jung, T.-P., et al. (2000). Removing
>> electroencephalographic artifacts by blind source separation.
>> Psychophysiology, 37, 163–178.
>>
>> On removing blinks with ADJUST: Mognon A, Bruzzone L, Jovicich J, Buiatti
>> M, ADJUST: An Automatic EEG artifact Detector based on the Joint Use of
>> Spatial and Temporal features. Psychophysiology 48 (2), 229-240 (2011).
>>
>> Hope this helps,
>>
>> Marco
>>
>>
>>
>>
>> On 5 August 2014 08:53, bjj2909102003 <bjj2909102003 at 163.com> wrote:
>>
>>> Hello,
>>> I want to use ICA to reject eye blink. But for some subjects it is easy
>>> to find eye blink component, for others  it is hard to find blink component
>>> even I use the plugin-ADJUST. So does ICA extract eye blink component
>>> without fail??
>>>
>>> Thanks so much!
>>> Booer
>>> ------------------------------
>>>
>>>
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>>
>>
>>
>> --
>> Marco Buiatti, PhD
>>
>> CEA/DSV/I2BM / NeuroSpin
>> INSERM U992 - Cognitive Neuroimaging Unit
>> Bât 145 - Point Courrier 156
>> Gif sur Yvette F-91191  FRANCE
>> Ph:  +33(0)169.08.65.21
>> Fax: +33(0)169.08.79.73
>> E-mail: marco.buiatti at gmail.com
>> http://www.unicog.org/pm/pmwiki.php/Main/MarcoBuiatti
>>
>> ***********************************************
>>
>>
>
>
> --
> Marco Buiatti, PhD
>
> CEA/DSV/I2BM / NeuroSpin
> INSERM U992 - Cognitive Neuroimaging Unit
> Bât 145 - Point Courrier 156
> Gif sur Yvette F-91191  FRANCE
> Ph:  +33(0)169.08.65.21
> Fax: +33(0)169.08.79.73
> E-mail: marco.buiatti at gmail.com
> http://www.unicog.org/pm/pmwiki.php/Main/MarcoBuiatti
>
> ***********************************************
>
>


-- 
Marco Buiatti, PhD

CEA/DSV/I2BM / NeuroSpin
INSERM U992 - Cognitive Neuroimaging Unit
Bât 145 - Point Courrier 156
Gif sur Yvette F-91191  FRANCE
Ph:  +33(0)169.08.65.21
Fax: +33(0)169.08.79.73
E-mail: marco.buiatti at gmail.com
http://www.unicog.org/pm/pmwiki.php/Main/MarcoBuiatti

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