Hello all,
I'd like to use SPM 8 to carry out exploratory group level statistics on MEG data collected on a 306 channel Elekta system. I have a couple of questions; (1) I've preprocessed my data according to the SPM 8 manual up to the point of artifact rejection. I would like to use the peak-to-peak algorithm on the planar gradiometers only with a threshold value of 3000fT/cm. When I set up a batch process to implement the artifact detection module with values 3000 or 3e-10 I get discrepant and/or worrying results, i.e., rejecting nothing or every trial in the dataset. I assume I am not entering the correct value translating to 3000ft/cm. As a side note, I get different results with the MNE software peak-to-peak algorithm on the planar gradiometers (>3000ft/cm), albeit with different filters and sampling rates between the software. Any ideas? (2) Is it possible to carry out 2-nd order sensor level statistics on preprocessed, trial-averaged data (e.g., my MNE pre-processed fif data) after converting to SPM and creating images?
Thanks in advance
Kambiz
|