[FieldTrip] Time-frequency analysis without baseline

[Bence Szaszkó]

Hello fellow FieldTrippers, 

I am analyzing steady-state data where I first had to select the first 10s after a certain event and then, within these 10s chunks, create regular epochs of 2s length using the pop_regepoch function of EEGlab. I did the spectral analysis with Fieldtrip and it went just fine; but now, I have to perform time-frequency analysis of the first 2s of those 10s chunks (so the first epoch in every chunk); however, due  to the limitations of pop_regepoch, I do not have a baseline, but only the 2s, with time 0 being the time-locking stimulus.

So now, I cannot perform baseline correction on the data, as I do not have a baseline. Do you have any idea how to circumvent this? Keep in mind that the epoch before the epoch in question is not the preceding epoch in time, so we cannot use that unfortunately. Or is it okay to not correct the baseline at all? 

In the spectral analysis, I used a signal-to-noise ratio instead of raw or log power, where I divided the raw power of Frequency N through the sum of the raw powers of N-1, N-2, N+1 and N+2. Would this also work for the time-frequency domain, doing this for each timepoint and channel?

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/20230721/4e85c732/attachment.htm>