[Eeglablist] Polarity after ICA
arno at salk.edu
Tue Jul 10 06:18:50 PDT 2007
I apologize for the late reply.
> We are using fastICA to extract sources of somatosensory EPs and use the
> Dipfit2 function in EEGLab to localise the extracted sources.
> We import data and the ICA weight matrix using File->Import Data.
> Given that ICA weight matrix has undetermined polarity (sign), how does
> dipfit2 in EEGLAB handle the estimation of the orientation of the extracted
> dipolar source in this particular context ?
For component with inverted polarities, Dipfit will find dipoles
pointing in the opposite direction. This is that simple.
Hope this helps,
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