Hi there, hoping for some guidance,

A trial in my task looks like this:

<trial square_distractpos>

/stimulustimes = [1=focus; 800=distractpos; 1000=targetsquare; 1150=distractpos; 1550=white_out]

/correctresponse = ("j")

/validresponse = ("f","j")

/timeout = 2750

</trial>

The participant is to respond after presentation of the targetsquare and I'm interested in the latency between the presentation of the targetsquare and their response.  When I get my data back, all the latencies are 1200 except for the ones that had an incorrect response.  At the moment I haven't specified data at all - just getting the default.  Is there something you can suggest I specify in the data to get the latency info I need?

Many thanks, hope this makes sense.

Naomi

By default Inquisit starts polling for response after the *last* stimulus specified has been displayed, i.e., white_out at 1550. Latency is relative to that, and any prior key presses will be ignored. To change that, see the documentation for the /responsetime attribute.

Thanks Dave.  That explains it.  I've been trying to find the documentation you are referring to and cant.  Would you mind telling me where to look?  I've honestly been searching!

You can access the Inqusit docs on your computer via Inquisit's 'Help' menu. Alternatively, the docs are available online as well as for download in a variety of formats via http://www.millisecond.com/support/docs/.

You'll want to study the language reference for the /responsetime attribute as well as the "How to Control Response Timing" topic. I'd also recommend working through the "How to Control Trial Duration and Inter-Trial Intervals" as well as all tutorials (in case you haven't done so yet).

Thanks Dave.  

  Very helpful.  After your advice, my trials now look like this:  

<trial circle_distractprac>

/stimulustimes = [1=focus; 800=distractprac; 1000=targetcircle; 1150=distractprac]

/correctresponse = ("f")

/responsetime = 1000

/validresponse = ("f","j")

/posttrialpause = 1550

/timeout = 2750

</trial>

Yes.

Stimulus display depends on the systems display refresh rate. Onset's may vary according to that (i.e., what is the closest start of a refresh cycle available). Is this something to worry about: No, not in general. It's a natural consequence of how display technology works.

That is something only you can answer. I would recommend you generate some test data and perform your planned analyses on that data to ensure you've got everything you need.

Thanks so much Dave.

Hello,

I'm having trouble specifying one particular thing in the data.  My trials something like this:

<trial square_distractpos>

/stimulustimes = [1=focus; 800=distractpos; 1000=targetsquare; 1150=distractpos]

/correctresponse = ("j")

/responsetime = 1000

/validresponse = ("f","j")

/posttrialpause = 1550

/timeout = 2500

</trial>

I would like a record of which distractpos is used for each trial (the pics are chosen randomly from a bunch of distractpos.   when I ask for stimulusitem it gives me the focus cross, and when i asked for stimulusitem2 it says it doesn't exist.  I am getting trialcode which is helpful, but stimulusitem would let me know which particular picture was used and would be helpful too.  Can you advise?  I've looked at the column attributes.

Many thanks.

As detailed in the documentation, its

/ columns = [..., stimulusitem, stimulusitem, stimulusitem, ...]

for as many times as you need. No numbering.

Sorry about that.  Got it.  One more quick question:  Is there a way for the response not to interrupt the presentation of the following stimuli?  The participant is to respond to the targetsquare but at the moment, their response will cut short the final stimuli (distractpos). i.e.  It will only appear for the full 400ms if they haven't responded.  Is there a way for their response to be registered (measured) but to allow the next stimuli to appear for the full duration regardless of their RT?  

Big thanks 

<trial square_distractpos>

/stimulustimes = [1=focus; 800=distractpos; 1000=targetsquare; 1150=distractpos]

/correctresponse = ("j")

/responsetime = 1000

/validresponse = ("f","j")

/posttrialpause = 1550

/timeout = 2500

</trial>

See the documentation for the /responseinterrupt attribute.