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I'm creating an experiment using inquisit 3.0: i let people listen to positive, negative and neutral soundfiles, and simultanously record their brainactivity with an fMRI scanner. The reason i'm using inquisit is just to be synchronised with the fMR-scanner. 

I'm working with dutch and french people, and also with men and women, and each of these (four) groups have their 'own' soundfiles. There are two conditions: in condition A people listen the soundfiles in the next order: Positive - Negative - Neutral, in condition B people listen to the soundiles in the next order: Negative - Positive- Neutral.

I'm wondering if it's possible in Inquisit to 'group' these people, so that the program begins with the question 'French or Dutch?', 'Male or Female?', and then puts each of the participants in the A or B condition so that really 50% of the participants of each group is in the A or B condition (NOT RANDOMIZED: i'm working with a small sample of participants).

?

thank you!

Sure, that's perfectly possible. I suggest you set your script up to start with a <surveypage> that let's you select the different options (nationality, gender, condition) via dropdown menus or the like -- think of it as a configuration page. Then just have the surveypage /branch to an <expt> element that's set up to run the specified condition.

Best wishes from a fellow Inquisit user,

~Dave

Hi Dave,

thanks for your fast reply!

And how can I specify which trial follows from a multiple of conditions?

Would that be something like

/ branch=[if (dropdown.sex = male AND dropdown.language = French AND dropdown.condition = A) block.soundblockA]

with the branching made in the  <surveypage>menu?

kindest regards,

pauwel.

The branches should probably look somewhat like this

/ branch = [if(dropdown.sex.selectedcaption=="male" && dropdown.language.selectedcaption=="French" && dropdown.condition.selectedcaption=="A")block.soundblockA]

and so on for the remaining (combination of) conditions .

~Dave

Hi Dave!

thanks for your reply. I don't know why, but it just doesn't want to work. Can you have a small look to what i've programmed and tell me why he doesnt play the files? If it demands too much from your time... then so be. You've allready helped me a lot. Inquisit: ain't easy...

greetings,

pauwel.

<dropdown sex>
/ caption = "Sex"
/ options = ("female", "male")
</dropdown>

<dropdown language>
/ caption = "Language"
/ options = ("French", "Dutch")
</dropdown>

<dropdown condition>
/ caption = "Condition"
/ options = ("A", "B")
</dropdown>

<surveypage demographics>
/ caption = "Please answer the following questions"
/ fontstyle = ("Verdana", -16, true, false, false, false, 5, 0)
/ questions = [1=sex; 2=language; 3=condition]
/ branch = [if(dropdown.sex.selectedcaption=="male" && dropdown.language.selectedcaption=="French" && dropdown.condition.selectedcaption=="A")item.sounditemA]
/ branch = [if(dropdown.sex.selectedcaption=="male" && dropdown.language.selectedcaption=="French" && dropdown.condition.selectedcaption=="B")item.sounditemB]
</surveypage>

<survey demographics>
/ pages = [1=demographics]
/ responsefontstyle = ("Verdana", -12, false, false, false, false, 5, 0)
/ itemfontstyle = ("Verdana", -13, false, false, false, false, 5, 0)
/ itemspacing = 2%
/ showpagenumbers = false
</survey>

/ font = ("Courier New", -19, 700, 0, 49)
/ screencolor = (175, 175, 175)
/ txbgcolor = (255, 255, 255)
/ txcolor = (0, 0, 0)
/ validresponse = ("a" " ")
/ pretrialpause = 500
/ posttrialpause = 500
</defaults>

<item sounditemA>
/ 1 = "critic male NL.wav"
</item>

<item sounditemB>
/ 1 = "critic male FR.wav"
</item>

Pauwel,

Inquisit may not be easy, but it ain't that hard either. I suspect you're just starting out and haven't quite wrapped your head around Inquisit's basic design philosophy. I therefore suggest you take a step back and complete a few of the tutorials contained in the Inquisit helpfile *before* proceeding with designing your own procedures from scratch. In any case, here's a quick overview of the language's structure:

Generally, you're dealing with two broad classes of elements -- stimulus elements and container elements. Stimulus elements (<text>, <picture>, <sound>, etc.) and their respective attributes define which stimuli to use (e.g a set of pictures stored on your PC), how they should look like on screen (their position, size, etc.) and how they should be selected (e.g. randomly without replacement). Note that the <item> element is not a stimulus element per se, but rather an array-like data structure which stores items to be used by stimulus elements.

Container elements (<trial>, <block>, <expt>, etc.) on the other hand define the procedural flow and temporal structure of your experiment. A <trial> displays one or several stimulus elements in temporal order and collects a single response from the participant. A <block> element bundles a set of trials and defines in which temporal order they should be run. The <expt> element then bundles a set of <block> elements and defines in which order they should be run. Since conditional branching (/ branch) is one way to steer the experimental flow, it should be clear that only container elements can be used in branches.

At this point it should be evident why the code you posted cannot work: You're trying to branch to an <item> element and not a container element (e.g. <trial>). So, to solve the issue, set up proper <sound> stimulus elements for the wav-files and -- most importantly --  a set of <trial> elements to display the sounds (and collect responses). Then use these <trial> elements in your '/ branch' commands.

Best wishes from a fellow Inquisit user,
~Dave