Millisecond Forums

Hi Dave - many thanks - I had made a mistake in placing squared brackets around list.waiting.nextvalue, which was producing an error message.

Thanks again!

Yes. It's perfectly possible to do. The proper syntax should be

/ timeout = list.waiting.nextvalue

Hi Dave - hopefully this is my last query - I was wondering if it were possible to use a list element for a timeout attribute? I'm afraid the simple answer might be no - however, I would like to essentially terminate a trial after a random interval, so that I have:

<list waiting>
/items = (300, 400, 500, 650, 800, 1000, 1500)
/poolsize = 7
/replace = true
/selectionmode = random
</list>

<trial waiting_s_1_500>
/stimulustimes = [100 = waitingstim]
/timeout = [list.waiting.nextvalue]
/branch = [trial.selftraining1countdownprac500]
</trial>

etc.

However, as you can imagine, Inquisit tells me that it contains an unknown element or property name - would it be possible to point me in the right direction (and I apologise if the solution is frustratingly simple)?

Many thanks,
Josh

Hi Dave,

I tried various formats, and thankfully .mov did not encounter the error - thanks for your suggestion.

Josh

Hmm, no spontaneous idea.
(1) Is your Inquisit installation up to date?
(2) Have you tried a different video format?

Hi Dave, thank you very much for you assistance - I thought latency and elapsed time would operate similarly in this instance, but your fix has provided relief!

I have another small, unrelated problem that has arisen - I can start another 'Question' or thread if you'd prefer, but, for now, I am having trouble with a video stimulus not fully erasing after presentation. Essentially I present a video stimulus, and whenever it continues to the next screen (whether it's another trial or block), a white shape of the same area/size as the video (in this instance, a medium-sized square) persists and covers up anything presented afterwards. I've tried multiple methods to my knowledge, but I still cannot remove it/prevent it from happening. If you could point me in the right direction if/when you have time, that would be very much appreciated.


<trial 1>
/stimulustimes = [1 = clock; 1999 = whiterectangle]
/correctresponse = (57)
/branch = [trial.2]
</trial>

<trial 2>
/stimulustimes = [1 = connecting2]
/correctresponse = (57)
</trial>

<block FUCK>
/trials = [1 = 1; 2 = 2]
</block>


<item connecting>
/1 = "Now you will begin the main experiment.

Press space to search for another Prolific Academic user."
</item>

<text connecting>
/fontstyle = ("Arial", 3.00%, false, false, false, false, 5, 1)
/txcolor = (black)
/items = connecting
</text>

<trial connecting>
/stimulustimes = [1 = connecting]
/correctresponse = (57)
/branch = [trial.waiting]
</trial>

-----

<video clock>
/items = ("libet0.avi")
/playthrough = false
/loop = true
/size = (20%, 20%)
</video>

<item waiting>
/1 = "Please wait while we connect you to another user..."
</item>

<text waiting>
/fontstyle = ("Arial", 3.00%, false, false, false, false, 5, 1)
/txcolor = (black)
/items = waiting
/position = (50, 80)
</text>

<trial waiting>
/stimulustimes = [1 = clock, waiting]
/timeout = 1000
</trial>

-----

<item connecting2>
/1 = "You are now connected with another Prolific Academic user!

Press the space bar to continue."
</item>

<text connecting2>
/fontstyle = ("Arial", 3.00%, false, false, false, false, 5, 1)
/txcolor = (black)
/items = connecting2
</text>

<trial connecting2>
/stimulustimes = [1 = connecting2]
/correctresponse = (57)
</trial>

-----

<block connecting>
/trials = [1 = connecting; 2 = waiting; 3 = connecting2]
</block>

Many thanks,
Josh

A <trial>'s response property returns the numerical keyboard scancode (see Tools -> Keyboard Scancodes...), not "q". Hence

trial.selfcountdownprac500.response == "q"

will not work.

Moreover,

(trial.selfcountdownprac500.elapsedtime<3850 && trial.selfcountdownprac500.elapsedtime>4150)

makes no sense as a condition. The elapsed time cannot be BOTH smaller than 3850 AND greater than 4150 at the same time, i..e the logical AND (&&) makes no sense here.

In sum, I'd rephrase the /branch a something along the lines of

/branch = [if(trial.selfcountdownprac500.latency>=850 && trial.selfcountdownprac500.latency<=1150 && trial.selfcountdownprac500.response == 16) trial.selfprac500 else  trial.selfclickprac500error]

Side note: The "Q" key is potentially a bad choice. It inhabits different positions on different-language keyboards, and thus will have different scancodes associated with it across languages: The scancode will be 16 on the English QWERTY layout, but not on e.g. a French AZERTY keyboard, where scancode 16 will be associated with the "A" key.. Scancodes reflect physical position of a key on the keyboard, rather than the letter imprinted on it.