[Eeglablist] ICA weights blowing up

[Alana Firl]

Hi, my lab has been using ICA to identify blinks and other artifacts.
However I've found that about 20% of subjects appear to have data that ICA
can't find a good solution for. runica takes hours to do just a few steps
and eventually matlab crashes. All of our data after acquisition is
processed in eeglab. The data is 128 channels, which we reduce to 75 using
PCA. After premilinary artifact rejection, each subject has about 30 minutes
worth of epoched data. I use extended runica, although other versions of ica
didn't do any better. I did some troubleshooting with the data and runica.m
and it seems as though, for the "bad" subjects, the weights are blowing up
every time. For some subjects, their data is just poor quality but for
others, their data looks clean, and I don't know why ICA isn't working for
them. Is there anything I can do to get around this problem?
Thanks!
Alana Firl
UC Davis
Imaging Research Center
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