Dear Mariyadasu,

You will have to be a little bit more specific, I don't really understand what you are asking about. You want to "take EEG signal" as input to what? And what would an "EEG database" be?

You can try browsing through Brainstorm software website https://neuroimage.usc.edu/brainstorm/Introduction . Another resource you can make use is Mike X Cohen lectures http://mikexcohen.com/lectures.html .

hello Madam,

Thank you for your concern. I want to take EEG signal as input for implementing PCA, ICA algorithms.

Ah, I see! I thought you are after the preprocessing and trying to analyse the data. In that case you can either 1) write your own tools to implement the ICA and PCA if you wish, 2) use existing tools to do so. I would strongly recommend the second, especially if you are new to the field. There are commercial solutions out there, for example Brain Vision Analyzer, which offers easy and user-friendly graphical interface, but is quite costly. You can also use the free toolbox EEG LAB for MATLAB (which itself isn't free but universities usually offer licences for it). There are plenty of tutorials online, just google them.

There are a few other steps you should perform on your raw data in the pre-processing other than ICA. Look for example at the answers in this question: https://www.researchgate.net/post/How_to_evaluate_N170_N200_P300_N400_and_P600_from_EEG_signals#view=5bea9e8ca7cbafb3466a5635 for some overall ideas.

Good luck!