[Eeglablist] Frontal Alpha Asymmeytri Score Problem

[Cedric Cannard]

Hi,

I believe you don’t need to remove baseline as high pass filter does it.
Average-referencing is generally done before ICA yes, with different ways to avoid rank-deficiency: https://sccn.ucsd.edu/wiki/Makoto's_preprocessing_pipeline#Re-reference_the_data_to_average_.2808.2F02.2F2020_Updated.29

https://sccn.ucsd.edu/wiki/Makoto's_preprocessing_pipeline#Re-reference_the_data_to_average_.2808.2F02.2F2020_Updated.29However, you need at least 64 channels for average reference. REST-referencing (https://urldefense.com/v3/__https://eeglab.org/tutorials/05_Preprocess/rereferencing.html__;!!Mih3wA!QwRQLdES0NHwOOyLx7EJoyOk8I-135EeWVT2VLmlmVi0c7NaGcLtJAj0KwlFt4nZNHyJCg$ ; bottom) can be done with at least 16 channels, not sure what happens with 14.
I am not aware of a paper testing it on this EEG setup. Comparing how asymmetry scores are affected by the referencing with another system with 16 channels could help.

More info on EEG asymmetry and referencing for your other questions: https://urldefense.com/v3/__https://www.sciencedirect.com/science/article/abs/pii/S016787601630784X__;!!Mih3wA!QwRQLdES0NHwOOyLx7EJoyOk8I-135EeWVT2VLmlmVi0c7NaGcLtJAj0KwlFt4nQuT5JOQ$ 

https://urldefense.com/v3/__https://www.sciencedirect.com/science/article/abs/pii/S016787601630784XC**Adric__;w6k!!Mih3wA!QwRQLdES0NHwOOyLx7EJoyOk8I-135EeWVT2VLmlmVi0c7NaGcLtJAj0KwlFt4no7t76jg$ 

On Sat, Feb 20, 2021 at 05:28, gökhan alper figen <gokhanalper at gmail.com> wrote:

> Hi everyone,
> i have phd project. My eeg device is emotiv epoc + 14 channel.
> I applied on EEGLAB for raw egg preprocess:
> 1-remove baseline(for time)
> 2-select channel
> 3-load channel location
> 4-remove epoch baseline(DCOFF)
> 5-1-45 Hz Fır-filter
> 6-???? i dont apply re-reference. Because my device reference is
> Mastoid(P3-P4). But i am not sure for this step. I tried
> re-reference(average), but this time ICA calculate one a component is under
> calculated. HELP ME. Is it necessary to re-reference?
> 7- ICA
> 8-Remove for Artifact applied ADJUST
> 9- Last one on matlab, i applied frontal alpha asymmetry algorithm(8-13Hz).
> But i have got another problem in here. I got AF3-AF4, F7-F8, F3-F4,
> FC5-FC6 dipole electrode on frontal lobe. Which dipole is important frontal
> alpha asymmetry? Used one by one at different times in the literature.İn
> addition i have different score same trial(for example: AF3-AF4-->positive,
> F7-F8--> negative, F3-F4-->positive, FC5-FC6-->negative ). is it possible?
>
> FAA SCORE:
> AF4-AF3 F8-F7 F4-F3 FC6-FC5 MeanFAA
> 0,835219 1,803982 0,768355 1,929266 1,334206
> 1,552542 0,523332 1,283658 0,662677 1,005552
> 0,212559 0,767369 -0,09146 0,533678 0,355537
> 2,695686 0,651778 0,208955 1,1194 1,168955
> 0,021023 0,745326 0,28 1,529339 0,643922
> 0,400539 0,693247 0,435739 1,952571 0,870524
> 0,069624 0,294606 1,358425 0,82884 0,637874
> 0,646927 0,528689 0,728926 1,521723 0,856566
> 0,260962 -0,12185 1,093646 1,173347 0,601527
> 1,228531 1,233191 1,044209 1,793257 1,324797
> 0,020307 0,647727 1,570798 1,414552 0,913346
> -0,58441 0,484781 0,804384 1,398788 0,525887
> 1,199436 1,282988 0,766968 1,721898 1,242822
> -0,2001 -0,69111 0,976038 1,513998 0,399708
> 0,184563 1,183316 1,678075 2,736944 1,445725
> -0,10969 0,93127 0,343262 0,51734 0,420546
> -0,22403 0,445983 -0,2119 0,763368 0,193354
>
> thanks
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