strange sensor signals in the baseline

Michael Wibral wibral at BIC.UNI-FRANKFURT.DE
Fri May 9 16:55:11 CEST 2008

Dear Fieldtrippers,

I have some data from a 275ch CTF system, that were (in each single subject) preprocessed in Fieldtrip with baseline correction and detrending. If I now look at the grandaverage ERP some sensors have a nonzero signal that is entirely on one side (either completely above or completely below) of the baseline, while most sensors oscillate around zero as I would expect. Is this an effect of detrending, i.e. is detrending performed AFTER baseline correction AND on the whole datapiece, instead of just the specified baseline interval?

Any suggestions welcome.


The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also and
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Michael Wibral.vcf
Type: text/x-vcard
Size: 443 bytes
Desc: not available
URL: <>

More information about the fieldtrip mailing list