[Eeglablist] (ask) about averaging and ICA

[Andrew Hill]

On Dec 23, 2010, at 4:09 AM, Bagas Isadewa wrote:

> hello,
> 
> i have several questions, 
> 
> 1. if I wanted to average EEG data to yields good ERP, how many minimum trials do I needed ? is there any paper or journals that explained about it ?

I suggest Steve Luck's book (An Introduction to the ERP Technique), and the documentation/tutorial that is part of ERPLab (an EEGLab plugin).

> 2. then, if I wanted to run ICA to extract ERP, do I need many trials or only single-trials in one epoch will be enough ??

Not really sure what you are asking... by definition an epoch will only have one trial.

> 3. is it necessary to run ICA first then do averaging or it is enough to use only one technique for extracting ERP ?

ICA first - averaging will transform the data in a way that will make ICA results not make sense.  I'm fairly certain this is true, but perhaps someone else will have a more well-reasoned answer.

Best,
Andrew 



> 
> if you don't mind please give me an explanation
> thank you very much
> 
> 
> regards,
> bagas isadewa
> 
> 
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