[Eeglablist] ICA with bad electrodes

[Paolo Andre]

Dear all,
a discussion arised in our lab  (between biologists and engineers) whether, 
having some (in the order of 10 out of 64 ) very bad channels producing a 
lot of different artifacts due two high impedance, bad skin contact or 
movement, the more correct and succesfull solution  is:
A:  to eliminate such channnels (and eventually the controlateral 
symmetrical ones) from the dataset before performing ICA , thus reducing 
the number of channels recorded or
B: perfoming ICA on the all dataset hoping that ICA  will segregate bad 
channels in  separate components.

A further question: theoretically  is it better to have symmetrical 
distributed electrodes for example on the right left side of the brain or 
ICA works as well with unbalanced montages?

Can somebody help. Best Paolo