[Eeglablist] paradox in whitening

[Mo Khalili]

Hi,



I have a general query about performance of ICA algorithms.
As I know FastICA is trying to estimate sources based on maximizing the non-gaussianity while, infoamx is trying to estimate the components based on minimizing mutual information between sources. What wonders me is , when I calculated the mutual information between ICs, the averaged mutual information between pairs of ICs in  FastICA is lower than ICs estimated by infomax. Additionally when I calculate the correlation between pairs of the estimated ICs, the averaged absolute correlation between ICs obtained by FastICA is significantly lower than infomax.
in my opinion this result speculates, the whitening(sphering) step in the infomax is different from FastICA, and it does not perform the same. 
However, when I look at the codes of FastICA and infomax, both have used the same method (and functions) for whitening.
I appreciate it if anyone can help me through understanding the reason.

Regards,
Mo
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