Different channels: noise covariance and recordings?

[sgirgen1]

Hi Francois,

Apologies - I am also a beginner on Brainstorm, and I am also receiving a similar error that I don't quite understand. I was able to calculate the head model and the noise covariance from the recording segments, but when I try to compute the sources, this error is telling me the noise covariance and recordings have different bad channels?

Thanks for any advice,
Sophia

[Raymundo.Cassani]

Hi Sophia,

As the error indicates, there is a difference in the bad (and therefor the good) channels in the noise-covariance and the recordings. This could happen in this situation:

• The noise covariance contains bad channels that were good when doing SSP/ICA artifact removal on the recordings.

Detailed information on this can be found in here:

Scout time series visualisation error

The difference in bad channels, does explain it. They must have the same bad channels, the fact that it works for the good folder is only chance. This is the long explanation: one difference between the good and the bad folders is that in the first, one SSP component is removed, and in the second no component is removed when doing EOG artifact removal. When computing the inverse model the noise covariance is loaded, and as expected, the rows and columns for the bad channels (PO3 and POz) are …

Can you provide more details on the steps that were taken to compute the noise covariance, and how the pre-processing of the recordings was performed?

If you are a new Brainstorm user, we recommend you start by following the introduction tutorials first (section "Get started" on the tutorial page), using the example dataset that is provided.
https://neuroimage.usc.edu/brainstorm/Tutorials

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The post was moved to its own thread as it was not pertinent to the other thread