Using ICA on EEG signals for feature extraction
How do I know I am not extracting noise (they are all very similar)?


You should first find or record a well understood set of signals with which you can test your feature extraction code to verify your setup is correct and that the extracted components are as expected.

Then you'll have higher confidence that you're not extracting noise due to errors in your code and you can focus on tuning your algorithms or reproducing other's results.