[FieldTrip] ERPs "the other way round"

[Bence Szaszkó]

Dear Group Members,

I am struggling a bit with an ERP analysis in Fieldtrip - calculating distractor positivity (Pd), I subtracted ipsilateral from contralateral effects. I get an effect, but exactly the opposite as expected. I looked at my code multiple times and did not find any mistakes. 

However, when looking at channel positions in data.elec.chanpos, it appears that the coordinates for Biosemi 128 are „flipped“ between X and Y, so instead of XYZ it is YXZ. Is this common or could this be the reason for my results?

Kind regards,
Bence

-- 
Bence Szaszkó, BSc MA MSc
University Assistant (prae doc)

Vienna Doctoral School CoBeNe 
PhD Representative

University of Vienna
Faculty of Psychology
Department of Cognition, Emotion, and Methods in Psychology

Liebiggasse 5
A-1010 Wien/Vienna
Austria

e-mail: bence.szaszko at univie.ac.at

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20230713/1b47b647/attachment.htm>