[Eeglablist] ERP localisation with BESA and DIPFIT with ICA

[IMALI THANUJA HETTIARACHCHI]

Dear EEGLAB list,

While reading through papers for my experiments, I just became curious (with some confusion) on the dipole fitting approach of the ERP data(for a specific task).

According to my understanding the ERP wave consists of several components such as P1,N1, P2 , N2 and P3 mainly (stimulus dependent). As I am intending to use ICA based source localization(using DIPFIT plugin) I wanted to find out on what degree the two dipole fitting approaches are differing in BESA and  DIPFIT with ICA.


1.       Am I correct if I say that with BESA, dipoles can be fitted to individual components of the ERP waveform?

2.       Do independent components for cognitive activity in brain represents ERP components(P1,N1, etc)?

3.       Since I have minimal(correct to say no..) experience in ERP, how do I know my dipole localisations with ICA are correct? For instance, in a visual task I would expect to see one or more dipoles in visual area, but when changing the conditions such as colour or shape where else do I get dipoles? Or simply, how do I have a hypothesis for the ICA component related dipoles?

4.       With very limited neuroscience knowledge how do I get around with localisations to extract a task related neuronal activity?

Sorry about throwing a lot of questions at the list, but I have always found EEGLAB list as very friendly and a very expertized group. So, your advice will be highly appreciated to move forward in my work.

Best regards
Imali

Imali Thanuja Hettiarachchi
PhD Candidate
Centre for Intelligent Systems research
Deakin University, Geelong 3217, Australia.
Email: ith at deakin.edu.au<mailto:ith at deakin.edu.au>
www.deakin.edu.au/cisr<http://www.deakin.edu.au/cisr>

[Description: Description: Description: cid:1216BE20-1800-4A47-8B9F-E7B9D94831CD at deakin.edu.au]




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