EEG in E-Prime: Sending triggers during a slide

[Tobias]

Hi there,

I have the following problem: I want to show a slide for 200 ms, allowing responses up to 1500 ms after slide onset. As I am doing an EEG experiment, constant slide presentation time is recommended which is why I set EndResponseAction to "None". Is it possible to send a trigger during the 200 ms interval, i.e. in case a participant pressed the button after 145 ms, there will be a marker in the EEG at that point in time? I only know the procedure of sending triggers with the onset (or offset) of a slide, e.g.

search.OnsetSignalEnabled = True
search.OnsetSignalPort = &HD030

But that doesn't help here since the trigger would obviously wait until the next slide comes no matter when I react in case I selected "None" for EndResponseAction.

Thanks,
Tobias

[David McFarlane]

Tobias,

Try searching this group using the word "trigger", you should find a
thread there that addresses your problem (I know, I just did this
myself -- currently about the 5th one down, but take a look around).

-- David McFarlane