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Hello everyone,

I am new to EEG analysis with SPM. I have followed the tutorials in the manual carefully and have managed to get reasonably far on my own, but I am stuck when it comes to digging inside the D meeg object for specific pieces of information.

I have fMRI data and EEG data (collected separately) of subjects viewing faces. So far, I have performed the standard SPM analysis on fMRI data. I have identified the clusters of interest and the corresponding coordinates of the centroids of those clusters in MNI space.

Now this is what I want to do:

1. Find the point in the EEG data (vertex or sensor) which most closely corresponds to the centroids of the fMRI activation

2. Extract the time courses for the those points in the EEG data

So far I have entered the coordinates of the fMRI centroids into the "ms or mm" box below the MIP button on the 3D Source Localization window on SPM, then hit the MIP button. This appeared to provide EEG coordinates that were very close to the fMRI coordinates and gave the time (in ms) of peak activity at that coordinate.

For example, if I enter [-39, -46, -23] (obtained from fMRI), the EEG MIP returns [-39, -45, -22] with peak at 195ms.

But now that I have that coordinate (which I assume is the vertex in the EEG data closest to the coordinates I entered), I do not know how to extract the time course of EEG activity associated with it.

This seems like it ought to be easy enough (and there are surely better ways than what I have tried so far), but don't know how to be sure I am getting the correct information.


I would greatly appreciate some help on this. 

Also, if there any straightforward guide out there to the information contained in the D meeg object, I would love to read it.

Thank you!

John