[Eeglablist] Are the results more significant on the scalp or inside brain?

[Michal Vavrecka]

Hello,

I do have few simple questions and I am curious about your intuitions 
and arguments:

I am finishing the paper where I did group analysis of two cognitive 
states. I visualized both scalp maps and dipoles and their statistical 
tests. Both visualization are based on fieldtrip monte carlo permutation 
with cluster based statistics (correction for multiple comparison). I 
would like to interpret the difference between results on the scalp and 
inside the brain (DIPFIT). What are your intuitions:

  Should the effect be stronger (in terms of more statistically 
significant electrodes (dipoles) and timeperiods) on scalp electrodes or 
in DIPFIT clusters?

How to interpret the stronger effect on the  scalp?
Does the ICA and DIPFIT calculation somehow weaken the ERSP difference?
My intuition is opposite as the source reconstruction has to clean the 
noise and strengthen the effect that should result in more statistically 
significant timeperiods in the spectrograms compared to scalp data?
Is there any paper that compares these two approaches?

Thanks for your answers.

Michal



-- 
Michal Vavrecka
assistant professor
Biodat Research Group
Incognite Research Unit
FEE CTU
Karlovo nam. 13
Prague 2
phone: +420224357609
cell: +420608661977
personal: http://bio.felk.cvut.cz/~vavrecka/
groups: http://incognite.felk.cvut.cz/
http://bio.felk.cvut.cz/