Millisecond Forums

In Inquisit, a <trial> registers a *single* response. Thus, it is not possible to do this. The next-best thing you can do is run two trials in sequence -- one to register the 1st button press, another one to register the 2nd.

Thank you. I guess I'll have to make due with the one

Is it possible to have the participant press one button and be required to press another button within x number of milliseconds in order to give the correct response?

Yes, but as with your initial request above, you need two <trial> elements to do that. You can do the response evaluation via /iscorrectresponse a la

/ iscorrectresponse = [... && trial.2ndtrial.latency < 2000]

Is this what you mean? I want it so the valid response is this [("m") && trial.late.latency < 2000] but it wont allow me to put that in the validresponse

<trial late>
/ validresponse = ("z")
/timeout = 15000
</trial>

< trial  era >
/stimulusframes = [1=era, erastim]
/timeout = 3500
/validresponse = ("m")
/ iscorrectresponse = [("m") && trial.late.latency < 2000]
/responsetrial = ("m", method)
</trial>

Your syntax in the /iscorrectresponse attribute is incorrect. It ought to be

/ iscorrectresponse = [trial.late.response == *ENTER THE NUMERICAL KEYBOARD SCANCODE FOR M HERE* && trial.late.latency < 2000]

For the appropriate scancode to enter above, see the "Keyboard Scan Codes" topic in the documentation as well as Tools -> Keyboard Scancodes...

I got an error that says invalid text

<trial late>
/ validresponse = (50)
/timeout = 15000
</trial>

< trial  era >
/stimulusframes = [1=era, erastim]
/timeout = 3500
/validresponse =  [trial.late.response == (44) && trial.late.latency < 2000)]
/responsetrial = ("m", method)
</trial>

#1: You need to use */isvalidresponse*, not */validresponse*
#2: Your syntax is still wrong. It ought to be:

/ isvalidresponse =  [trial.late.response == 44 && trial.late.latency < 2000)]

no more error messages but pressing the buttons at the same time does nothing. 

<trial late>
/isvalidresponse = [(50)]
</trial>

< trial era >
/stimulusframes = [1=era, erastim]
/timeout = 15000
/ isvalidresponse = [trial.late.response == 44 && trial.late.latency < 2000]
/responsetrial = (" ", method)
</trial>

< trial method >
/stimulusframes = [1=iorm, iorm2]
/timeout = 15000
/ validresponse = ("z" "m")
/branch = [(openended.open)]
</trial>