Millisecond Forums

I see what you are saying.

This is what I want:

Fixation 3 sec, Prime word 400ms, Mask 3 sec, Target word 




Ashley

The corresponding /stimulustimes definition, then, would look like this:

/ stimulustimes = [0=fixation; 3000=prime; 3400=mask; 6400=target]

i.e. display "fixation" at t0,
display the "prime" 3000ms into the trial,
display the "mask" 400ms later, i.e. 3400ms into the trial,
display the "target" 3000ms later, i.e. at 6400ms into the trial.

If you wish to erase any prior stimuli in-between, you can do

/ stimulustimes = [0=fixation; 3000=blankscreen, prime; 3400=blankscreen, mask; 6400=blankscreen, target]

where "blankscreen" is a <shape> covering the previous stimuli

<shape blankscreen>
/ shape = rectangle
/ color = white
/ erase = false
/ size = (100%, 100%)
</shape>

Hope this helps.

Thank you, that did help! I have it programmed in a test experiment that is abbreviated to just a few practice trails to get it right before changing my entire program. I have ran this twice and it works, however after the two trials are complete the screen appears to "freeze"- Control Q is not working. Any idea what is causing this?


Ashley

I'd have to see the code.

One guess: You've mistakenly specified something like

/ stimulusframes = [... ; 6400=target]

in some <trial> element(s), which works out to _much_ longer timings (between 10 and 20 times longer), which can easily give the appearance of "freezing." Double-check if you've used /stimulustimes throughout.

My apologies, I meant to attach it. Here it is. 

Here's the problem:

<trial quininescript_Norbert>
/validresponse = ("E", "I")
/correctresponse = ("E")
/ stimulustimes = [0=fixation; 3000=blankscreen, quininescript; 3400=blankscreen, mask; 6400=blankscreen, Norbert]

/beginresponseframe = 6400
/posttrialpause = 1500
</trial>

You've instructed the <trial> to only start accepting responses starting in its 6400th _frame_, i.e. between 1 to 2 _minutes_ into the trial (depending on the display's refresh rate). Your two trials should read:


<trial quininescript_Norbert>
/validresponse = ("E", "I")
/correctresponse = ("E")
/ stimulustimes = [0=fixation; 3000=blankscreen, quininescript; 3400=blankscreen, mask; 6400=blankscreen, Norbert]
/beginresponsetime = 6400
/posttrialpause = 1500
</trial>

<trial NORmanTM_NORbertTM>
/validresponse = ("E", "I")
/correctresponse = ("E")
/stimulustimes = [0=fixation; 3000=blankscreen, NORmanTM; 3400=blankscreen, mask; 6400=blankscreen, NORbertTM]
/beginresponsetime = 6400
/posttrialpause = 1500
</trial>

So when should the response time begin? I chose 6400 since that was the last time I had. 

Depends on when you _want_ it to begin. If you wish to measure latency _relative_ to the appearance of the target, theb /beginresponsetime should be set to 6400ms. If you wish to measure latency relative to the appearance of the prime, then /beginresponsetime should be set to 3000ms.

I want the next trial to begin immediately following the response to the current trial.