[Eeglablist] Transferring ICA weights from pruned data to original (moderately cleaned) dataset results in non-smooth activity power spectrum

[Arnaud Delorme]

Dear Amélie,

Look at your plots and you will see that the scale is very difference which should explain the difference you observe.
Best wishes,

Arno

> On Oct 2, 2018, at 1:27 AM, Roi, la, A. <a.la.roi at rug.nl> wrote:
> 
> Dear list,
> 
> When preprocessing my EEG data, I run ICA on a heavily cleaned dataset. Subsequently, I transfer the ICA weights to the original dataset, which is only moderately cleaned. The number of channels in the two datasets are the same and both are re-referenced to average reference (therefore, I use the 'pca', [number of channels in dataset - 1] settings when running ica). 
> 
> Component 1 and 6 probably reflects blinks and horizontal eye movements, respectively. When I plot the components in the pruned dataset, the activity power spectrum looks fine (see attachment: ptc5_component1_pruneddata.png and ptc5_component6_pruneddata.png). However, when I plot the components in the original dataset, the activity power spectrum of both components contains bumps, while the scalp plot remain the same (see attachment: ptc5_component1_originaldata.png and ptc5_component6_originaldata.png). Does anyone know what's going wrong here? The component activations when plotted in the original dataset still indicate that component 1 and 6 reflect blinks and horizontal eye movements, respectively, although the component activation plot does contain a bit more noise than the component activation plot of the pruned data.
> 
> Any comments are welcome!
> 
> Kind regards,
> Amélie la Roi
> 
> -- 
> Amélie la Roi, MA
> PhD student CLCG, Semantics and Cognition
> University of Groningen, the Netherlands
> Harmony building, room 1311.0412 | Phone: +31 50 363 6683
> 
> <ptc5_component1_originaldata.png><ptc5_component1_pruneddata.png><ptc5_component6_originaldata.png><ptc5_component6_pruneddata.png>_______________________________________________
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