I am new Brainstorm so , I apologize if the answer is basic or already answered.
I have done the following steps:
- Import MRI, surfaces, sensors (Ecog)
- Create an BEM head model
- Create N scouts. (N=100)
- Affect randomly 2 signals to 2 different scouts (2 chosen in the 100 availabled)
- Simulate Ecog recordings from the 2 scouts.
And now, I'd like to have the possibility to observe the reconstructed time series on the 2 selected scouts after beamforming.
I followed the steps: Computes sources-->LCMV Beamformer-->Cortical activation--> scout time series.
However, I observed that all the scouts own a non zero time series.
Is your question: why all the sources in the brain have non-zero values while only two ROIs were supposed to show activity?
This is expected: the minimum norm estimates or beamformer solutions always affect some activity, even very low, to all the dipoles in the source space in input.
If you need more details about these inverse methods, please refer to the literature cited in the Source estimation tutorial:
You should however be able to observe the estimated sources mostly concentrated around the ROIs in which you simulated data.
For a list of the simulation processes, please refer to this tutorial:
thank you for your reply!