[Eeglablist] Fix ICA rank deficiency in script

[Makoto Miyakoshi]

Dear Claudia,

> I just wanted to confirm that pop_runica will automatically adjust the
components possible to detect, based on the dataset's rank, as suggested by
the EEGLAB wiki.

No, I confirmed that at least in some conditions it fails. See this article.
https://sccn.ucsd.edu/wiki/Makoto%27s_useful_EEGLAB_code#How_to_avoid_the_effect_of_rank-deficiency_in_applying_ICA_.2803.2F31.2F2021_added.29

If you have further questions, please let me know.
Also, if you are interested in the open EEGLAB mailing list experiment on
the ICA rank issue--please let me know!

Makoto

On Mon, Apr 19, 2021 at 7:31 AM Krogmeier, Claudia M via eeglablist <
eeglablist at sccn.ucsd.edu> wrote:

> Dear list,
>
> I have seen past eeglablist posts concerning how to fix ICA rank
> deficiencies, by changing to PCA parameter in the pop_runica function to
> the appropriate number of components for ICA, with
>
> %EEG = pop_runica(EEG, 'icatype', 'runica',
> 'extended',1,'interrupt','on','pca',numberComps);
>
> with numberComps as the appropriate # to use, especially if EEG is
> averaged referenced or chans are interpolated.
>
> However, I have read on the EEGLAB tutorial page that: "If the rank of the
> data is lower than the number of channels, the EEGLAB pop_runica() function
> should detect it and uses different strategies to do so."
>
> I just wanted to confirm that pop_runica will automatically adjust the
> components possible to detect, based on the dataset's rank, as suggested by
> the EEGLAB wiki.  Other EEGLAB list posts have led me to believe that it
> may be necessary for the user to specify numberComps, rather than let
> pop_runica automatically handle a rank deficiency issue. I am using an
> automated script.
>
> Thank you very much,
> C
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