Millisecond Forums

StroopTask - How to repeat practice block, how to randomize items, How to program a fixation cross?

https://forums.millisecond.com/Topic28185.aspx

By DannyPilgrim - 1/29/2020

Hello everyone,

I have never worked with Inquisit before so These are actually more General Questions, I suppose:
I have programmed a Stroop Task so far with a Practice block which consists of 8 items. How can I repeat the block, when the subjects have made 4 Errors? (50/50)

Also I would like to know how I can ​randomize all my items within the blocks

Is it possible to Show a Fixation cross to the subjects before every Trial for 500ms?

Thank you for your help!

​​​​​​​​​​​
By Dave - 1/29/2020

DannyPilgrim - 1/29/2020
uHello everyone,

I have never worked with Inquisit before so These are actually more General Questions, I suppose:
I have programmed a Stroop Task so far with a Practice block which consists of 8 items. How can I repeat the block, when the subjects have made 4 Errors? (50/50)

Also I would like to know how I can randomize all my items within the blocks

Is it possible to Show a Fixation cross to the subjects before every Trial for 500ms?

Thank you for your help!


Generally, see the tutorials if you're new to creating tasks with Inquisit. Those will introduce you to the most important concepts: https://www.millisecond.com/support/docs/v5/html/tutorials/tutorials.htm

To repeat a <block> based on performance, you can use built-in performance metrics or build your own, more complex ones using <values> and /ontrialend logic. Then /branch based on the performance. In a nutshell:

> How can I repeat the block, when the subjects have made 4 Errors? (50/50)

<block practice>
...
/ trials = [1-8 = noreplace(congruenttrial, incongruenttrial)]
/ branch = [ if (block.practice.percentcorrect <= 50) block.practice]
...
</block>

https://www.millisecond.com/support/docs/v5/html/language/properties/percentcorrect.htm

> Also I would like to know how I can randomize all my items within the blocks

To randomize the order of trials, use the noreplace() selection mode in the block's /trials attribute

/ trials = [1-8 = noreplace(congruenttrial, incongruenttrial)]

To randomize items displayed by a <text> element in your trials, set the <text> element's /select attribute to noreplace

https://www.millisecond.com/support/docs/v5/html/language/attributes/select.htm

> Is it possible to Show a Fixation cross to the subjects before every Trial for 500ms?

You typically simply do this by displaying a fixation stimulus per the <trial>'s /stimulustimes as needed:

<trial congruenttrial>
/ stimulustimes = [0=fixation; 500=clearscreen, congruentstimulus, ....]
...
</trial>

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

https://www.millisecond.com/support/docs/v5/html/language/attributes/stimulustimes.htm

Also see the various Stroop scripts available in the library: https://www.millisecond.com/download/library/stroop/
By DannyPilgrim - 2/12/2020

Dave - 1/29/2020
DannyPilgrim - 1/29/2020
uHello everyone,

I have never worked with Inquisit before so These are actually more General Questions, I suppose:
I have programmed a Stroop Task so far with a Practice block which consists of 8 items. How can I repeat the block, when the subjects have made 4 Errors? (50/50)

Also I would like to know how I can randomize all my items within the blocks

Is it possible to Show a Fixation cross to the subjects before every Trial for 500ms?

Thank you for your help!


Generally, see the tutorials if you're new to creating tasks with Inquisit. Those will introduce you to the most important concepts: https://www.millisecond.com/support/docs/v5/html/tutorials/tutorials.htm

To repeat a <block> based on performance, you can use built-in performance metrics or build your own, more complex ones using <values> and /ontrialend logic. Then /branch based on the performance. In a nutshell:

> How can I repeat the block, when the subjects have made 4 Errors? (50/50)

<block practice>
...
/ trials = [1-8 = noreplace(congruenttrial, incongruenttrial)]
/ branch = [ if (block.practice.percentcorrect <= 50) block.practice]
...
</block>

https://www.millisecond.com/support/docs/v5/html/language/properties/percentcorrect.htm

> Also I would like to know how I can randomize all my items within the blocks

To randomize the order of trials, use the noreplace() selection mode in the block's /trials attribute

/ trials = [1-8 = noreplace(congruenttrial, incongruenttrial)]

To randomize items displayed by a <text> element in your trials, set the <text> element's /select attribute to noreplace

https://www.millisecond.com/support/docs/v5/html/language/attributes/select.htm

> Is it possible to Show a Fixation cross to the subjects before every Trial for 500ms?

You typically simply do this by displaying a fixation stimulus per the <trial>'s /stimulustimes as needed:

<trial congruenttrial>
/ stimulustimes = [0=fixation; 500=clearscreen, congruentstimulus, ....]
...
</trial>

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

https://www.millisecond.com/support/docs/v5/html/language/attributes/stimulustimes.htm

Also see the various Stroop scripts available in the library: https://www.millisecond.com/download/library/stroop/

Thank you very much!

I programmed it with your instructions and now it works!

Thank you for your help!​​

​​​​​​