[Eeglablist] Data rank and ICA results

[shiva khoshnoud]

Hello everyone,

I have a question regarding EEG data rank and ICA analysis. I have an EEG
set file with 31 channels recorded with Fz electrode as the reference. I
did the average re-referencing with adding the initial reference with zero
data value to the data by appending one channel  Fz, setting it as
reference and adding current reference back to Fz while re-referencing.
This procidure gave me a set file with 32 channels including Fz with data
rank 32.
Then I did ICA with AMICA. In most sets I got 31 components but in some I
got 32 components. Considering this fact that my data rank is now 32,
shouldn't I get 32 ICs?

Thank you so much,
Shiva






-------------------------------------

Shiva Khoshnoud

Postdoctoral researcher,

Institut für Grenzgebiete der Psychologie und Psychohygiene

Wilhelmstr. 3a
79098 Freiburg
Germany


Tel. +49 761 20721-71
Fax. +49 761 20721-91