[FieldTrip] ft redefine trials: how to change trigger?

[KatrinH Heimann]

Dear all,

my name is Katrin Heimann, I am phd student at the University of Parma. New
to Fieldtrip.
I am doing an EEG analysis, still in the preprocessing phase.
It is a within trials design. I would like to compare a baseline period
with an experimental condition (visual stimulus).

 I have a trigger after a fixation cross, then a baseline period (approx 1
sec) , then the period of my stimulus (1 sec- starting with a bottom press
(trigger)).

 As I would like to apply the same baseline correction for both (the
fixationcross period)  I planned to first define my trials as long trials
including the timewindows of baseline and the stimulus period, applying
filter and baselinecorrection on those long pieces. However, as I do not
wanna do the artifact detection on the whole pieces (but seperately for
baseline and stimulus, to avoid that I have to throw away too many trials)
I would like to redefine my trials then, cutting out only baseline period
and only stimulus period (starting with another trigger
(triggervalue=resp)..

*Unfortunately I do not understand how I can change the trigger used with
ft redefine trial. *

Anybody who could give me an example how that is done?
Thanks a million
Katrin
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