Problem in epoching

Hi!
I have a problem with epoching.
I can't epoch my data in a time range of -200 t0 500 ms. it is automatically epoched in 0-1000 ms windows.
how should I fix it?

Thank you!
Shadi

Please share some more explanations, screen captures showing your database, the input files, the option windows...


Hi Francois,
this is an image of my raw data. here the epochs are automatically set in1 second but I intended to set them in 500 ms. I think according to this preset by the software, there is no possibility to have -200 ms in epochs.

and here as you can see, when I want to set the epochs, the epoch time section is locked and cant be changed.( it happens when I choose my events)
by importing the data, I have epochs in 1 second (0-1000 ms post stimulus).

is my explanation enough? if not, I should send you my raw data in EDF format.

Best
Shadi

These are "extended events", their duration is explicitly defined.
When importing these events to the database, all the block is imported, there is no need (and no possibility) to define an extra time window around them.

If you want to change their duration, you need first to convert them to simple events (you'll find this as a menu in the Record tab, or as a process in the Events category).
Once their are defined as simple events, you'll be able to epoch them using the time window you want around the marker.

Hi!
now it's solved!

thank you Francois.

Shadi