Source estimation of certain frequency

1

I am trying to localize the onset of a seizure. This seizure is a likely to be frontal in origin and thus the EEG showed sudden diffuse attenuation on raw EEG. I did TF analysis using wavelet transform. I projected that data on the scalp for certain frequency that seemed interesting on the TF plot. The scalp map is not smooth which might reflect multiple source of that frequency. What I did, I did source localization of the raw EEG, applied TF analysis to the source space EEG then visualized the map on the cortex. It doesn't look right. Now my question, is it possible to localize such a frequency if the scalp map is not uniform?is there a way to smooth the map or to do source imaging of certain region?Is that advisable?
*I used sLORETA for source imaging.

Waleed

2

What do you mean with:

  • "projected that data on the scalp"
  • "The scalp map is not smooth"
  • "It doesn't look right"
  • "the scalp map is not uniform"?
    Please post screen captures illustrating your questions.

Have you followed the EEG/Epilepsy tutorial entirely, using the example dataset provided?

is there a way to smooth the map

I'm not sure I understand what you'd like to smooth.

do source imaging of certain region?

No, you can't restrict the minimum norm source estimation to a smaller source space. Otherwise, you would get all the EEG activity explained in this region only.