[FieldTrip] Decreased baseline level after using ICA in ERP data

[Beom Jun Min]

Dear all,

I have ERP data and now I am dealing with ICA to remove muscle and eye
artifacts.
However, I found that after ft_rejectcomponent, the baseline level of the
segmented epoch decreased. (The baselinewindow is [-0.2 0].)
The baseline level decreased even though I rejected only one component.

My script is shown below.

*%% Removing the Artifacts*
*cfg = [];
*
*cfg.component = [ ]; % to be removed component(s)*
*post_ICA_temp6 = ft_rejectcomponent(cfg, comp_detrand, data_raw);*
*
*
*%% timelocking*
*
*
*cfg = [];*
*timelock_temp6 = ft_timelockanalysis(cfg, post_ICA_temp6);*
*
*
*%% Plot*
*
*
*figure;*
*cfg = [];*
*cfg.layout = lay;*
*cfg.interactive = 'yes';*
*cfg.channel = ['all', {'-EKG', '-EMG'}];*
*ft_multiplotER(cfg, timelock_temp6)*

Is there something that I missed?

Thanks.

BJ

-- 
BeomJun Min, M.D.

Department of Medical System Engineering (DMSE)
Gwangju Institute of Science and Technology (GIST)
261 Cheomdan-gwagiro(Oryong-dong), Buk-gu, Gwangju
500-712, Republic of Korea (South)
Phone: +82-62-715-3266 / Fax: +82-62-715-3244
E-mail: mbj0310 at gmail.com, http://bmssa.gist.ac.kr
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