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If statements within trial's /stimulusframes?

DCole9 — Fri, 31 Oct 2014 10:26:53 GMT

Hi Inquisiters,
I'm running into a problem with a task-switching paradigm in which subjects have a choice between 2 colored patches. The patches are randomly assigned a high demand and a low demand condition which effects the display color of a number. The color of the number will effect whether they make an "even or odd" decision or a "> 5 or < 5" decision.

What I'm trying to do is setup my stimulus frames to display from the high demand number list when the certain criteria are true (random position variable = 1, they selected patch1, etc).

My question is: Do I need to set up individual trials for each possibility? (e.g. trialA for random position 1, select.patch1. trialB for random position 2, select.patch1. etc. etc.)

Or is it possible to use something like
"/ontrialbegin = [if((values.XX == 1( && (values.YY == 2 )) values.stimframes = "displaytext, displaynum, patch1, patch2]
/stimulusframes = values.stimframes"

or "/stimulusframes = [if ((values.XX == 1) && (values.YY == 2)) 1 = displaytext, displaynum, patch1, patch2]" ?

Thank you for your help!

RE: If statements within trial's /stimulusframes?

Dave — Fri, 31 Oct 2014 10:26:53 GMT

No, you do not. You need to use curly braces to bundle all the statements to be executed under the if-condition;

/ ontrialbegin = [if (true) { do stuff; do more stuff; do even more stuff; }]

Also, it's not clear to me why you use setstimulusframe() in both statements. You would only use it in the 1st and then insertstimulusframe() in all subsequent ones:

<list fixationduration>
/ items = (500, 5000, 10000)
</list>

<trial mytrial>
/ ontrialbegin = [if (true) {trial.mytrial.setstimulustime(text.a, list.fixationduration.nextvalue);
trial.mytrial.insertstimulustime(text.b, list.fixationduration.nextvalue); }]
/ ontrialend = [trial.mytrial.resetstimulusframes()]
/ stimulustimes = [0=fixation]
/ validresponse = (57)
</trial>

<text fixation>
/ items = ("+")
</text>

<text a>
/ items = ("A")
/ position = (45%, 50%)
</text>

<text b>
/ items = ("B")
/ position = (55%, 50%)
</text>

<block myblock>
/ trials = [1-3=mytrial]
</block>

RE: If statements within trial's /stimulusframes?

DCole9 — Fri, 31 Oct 2014 10:15:48 GMT

Ah got it. It's working now.

For your previous post I need to declare each stimulus frame as a separate line correct? When I separated them by semi-colons it didn't work.

For example)
"/ontrialbegin = [if ((values.randomposition == 1) && (trial.InitialSelect.response == "patch1") && (values.randomdemand == "lowpatch1")) trial.patchtrial.setstimulusframe(focus, 1);]
/ontrialbegin = [if ((values.randomposition == 1) && (trial.InitialSelect.response == "patch1") && (values.randomdemand == "lowpatch1")) trial.patchtrial.setstimulusframe(choose, 1);]"

RE: If statements within trial's /stimulusframes?

Dave — Fri, 31 Oct 2014 09:53:19 GMT

This won't work / is invalid syntax:

<text highnumber>
/items = ("")
/position = (50%, values.numbery)
/fontstyle = ("Arial", values.focussize, true, false, false, false, 5, 0)
/txcolor = (values.highnumcolor)
/txbgcolor = (white)
/select = values.numberget
</text>

The way to do this is defining

<text highnumber>
/items = ("")
/position = (50%, values.numbery)
/fontstyle = ("Arial", values.focussize, true, false, false, false, 5, 0)
/txbgcolor = (white)
/select = values.numberget
</text>

and then doing

/ ontrialbegin = [text.highnumber.textcolor=values.highnumcolor]

Also, you need to get rid of the double-quotes in

<list highdemandcolor>
    /items = (yellow, blue)
    /replace = false
    /selectionrate = trial
</list>

for the items to be interpreted as colors.

RE: If statements within trial's /stimulusframes?

DCole9 — Fri, 31 Oct 2014 09:25:23 GMT

My mistake I had since fixed that error. The other error is unrelated to that I think.

It is the element "text.highnumber" showing the error.

RE: If statements within trial's /stimulusframes?

Dave — Fri, 31 Oct 2014 09:16:57 GMT

/ontrialbegin = [if ((values.diceoutcome > 50 ) values.highnumcolor = list.highdemandcolor.nextvalue]

Notice the additional (superfluous / unmatched) parenthesis.

RE: If statements within trial's /stimulusframes?

DCole9 — Fri, 31 Oct 2014 09:12:53 GMT

That's perfect Dave!

One other (I think simple) question: In my code do you know why I am receiving the 'Expression " is invalid. Expression is empty.' error message? I have a text element declared that gets filled when a list cycles values, which I've done before, but it isn't working this time.

RE: If statements within trial's /stimulusframes?

Dave — Fri, 31 Oct 2014 09:05:42 GMT

Yes, it's possible. You need to use the <trial> element's insertstimulustime() etc. functions to do this. You cannot use <values> in the way you sketched.

See e.g. https://www.millisecond.com/forums/Topic10374.aspx#bm11148

For further details, see the language reference for the functions mentioned above.