Alternating Stimuli with Rating pages

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Alternating Stimuli with Rating pages

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ashaw	ashaw posted 11 Years Ago Topic Details Share Topic
Group: Forum Members Posts: 5, Visits: 22	Hi! I'm working on an experiment whereby I'm trying to alternate a stimuli page with a rating page. I know how to do this manually in the block element as follows: <block> /trials = [1,3= noreplacenorepeat(practiceTrial); 2,4= likertpracticeTrial] </block> However, I'm trying to automate this alternation using a counter since the number of pages that I have to alternate is quite large. I tried to define a count using the following code outside of the block: <values> count = 1 </values> Then I edited the trial code as follows: <trial practice> /stimulusframes = [1=practice] /ontrialbegin = [ values.count + 2] </trial> I then edited my block code from above as follows: <block> /trials = [values.count= noreplacenorepeat(practiceTrial); 2,4= likertpracticeTrial] </block> This count method did not work because Inquisit did not recognize values.count as being an integer and returned an error saying that trial1 was undefined. I I would appreciate any help in figuring out a simpler count method that can automate alternation of the pages. Thank you!
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Dave	Dave posted 11 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 108K	<block> /trials = [values.count= noreplacenorepeat(practiceTrial); 2,4= likertpracticeTrial] </block> The above is not possible -- it's invalid syntax and variables as trial numbers are not allowed. Why don't you simply do: <block> /trials = [1-2 = sequence(practiceTrial, likertpracticeTrial)] </block> ? Note that noreplacenorepeat(practiceTrial) makes no sense if you only have one element (here:practicetrial). Other options: #1: Use /branch to run the likerts as in <trial practicetrial> ... / branch = [likert.likertpracticetrial] </trial> <block someblock> / trials = [1-2=practicetrial] </block> #2: If you require really complex selection, use <list> elements. <list triallist> ... </list> <block someblock> / trials = [1-2=list-triallist] </block> For details, refer to the language reference on the <list> element. Unrelated addendum: <trial practice> /stimulusframes = [1=practice] /ontrialbegin = [ values.count + 2] </trial> is invalid syntax and ought to read <trial practice> /stimulusframes = [1=practice] /ontrialbegin = [ values.count += 2] </trial> '+=' is the increment operator; for details please refer to the 'operators' topic in the documentation.
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ashaw	ashaw posted 11 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 5, Visits: 22	The sequence command is perfect for what I need. Related to your branch suggestion however, if I did do a branch, could I time the trial and the branch within the trial separately? Additionally, I had one more quick question. Since I am dealing with a large number of picture stimuli, do I have to hardcode the name of each one individually in my item element, or is there a file reader that can pull in image files from a specified path ( something similar to the python capability)? Thanks again for the help!
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Dave	Dave posted 11 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 108K	> Related to your branch suggestion however, if I did do a branch, could I time the trial and the branch within the trial separately? A /branch is executed when the parent <trial> element terminates. So the answer is "no". > Since I am dealing with a large number of picture stimuli, do I have to hardcode the name of each one individually in my item > element? Yes. The reason is that Inquisit must make sure that every file the script needs actually exists and is available to avoid catastrophic runtime failures on optimize performance.
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