[FieldTrip] help for statistics on ERD/ERS

Tzvetan Popov tzvetan.popov at uni-konstanz.de
Tue Oct 7 21:07:37 CEST 2014


Hi Giulia,


> Dear Fieldtrippers
> I'm writing to ask you some help on data in a single subject study.
> I did a time frequency decomposition and I would like to do a statistic to state whether the average TFR has significant ERD/ERS or not.
> I'm not sure how to proceed
What you are referring to is a “between trial experiment” which is described in this tutorial:
http://fieldtrip.fcdonders.nl/tutorial/cluster_permutation_freq
One possible way to go is to compute the TFR’s with cfg.keeptrials = ‘yes’. Next you’d treat the baseline and the task interval as two conditions by separating them using ft_selectdata. After this you can compute the statistical comparison in a similar fashion as described in the tutorial. 
Keep in mind that you have to cut the data into equal lengths. Please have a look at this post : 
http://mailman.science.ru.nl/pipermail/fieldtrip/2007-July/001303.html 
> , as a first step I compared the single trial baseline with the respective event, with a t-test for each condition and band of interest but I'm not really sure if this is enough and anyway if it is the correct way.
Also please type “actvsblT” in the search bar and then click on “Search the FieldTrip mailing list”. There you’ll find some info about this.

best
tzvetan





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