[Eeglablist] group level analysis

[Dénes Szucs]

Thank you for your earlier reply.

Another question:
To assess group level data is the process outlined below the right 
one?
- perform ICA on individual data
- identify relevant components (ICs) - ?  according to their relation to 
stimulus onset and response time and similar power spectra?

- identify identical relevant components across subjects -- ? Is it 
usually possible to identify components across subjects? Is there an 
objective method for this or the researcher has to "subjectively" 
judge the similarity of ICs?

- average identical component loadings across subjects
--> is it possible this way to describe "group level" components?

But:
- What if some components are missing in some persons? Sould 
one accept this as an indication of individual variability and simply 
use only components accepted as identical from other subjects? Or 
is it due to data quality not good enough? It it possible to tell the 
quality of the data from the point of view of the ICA algorithm? (apart 
from the No of data points needed)


thank you, denes



Denes Szucs
Lecturer in Neuroscience and Education
University of Cambridge, UK
Shaftesbury Road, Cambridge, CB2 2BX, UK
Tel: +44-(0)1223 369631
Fax: +44-(0)1223 324421