Variable inter-trial interval in Alcohol Dot Probe Script

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Variable inter-trial interval in Alcohol Dot Probe Script

Variable inter-trial interval in Alcohol Dot Probe Script

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Leni	Leni posted 7 Years Ago Topic Details Share Topic
Group: Forum Members Posts: 2, Visits: 15	Hello, I´m currently adapting the Alcohol Dot Probe Script the way I want my experiment to work. I need help on how to compute a variable inter-trial interval. I want the inter-trial trial to vary randomly between the three values 500, 1000 and 1500ms. In the script the inter-trial value is set to 0 ( <values> /iti=0 </values> ) and integrated in the trial via the posttrialpause attribute (/posttrialpause = values.iti) How can I compute the variable inter-trial interval? What I tried so far: Created a list that randomly selects one of the three iti-durations </list itidurations / items = (500, 1000, 15000) /replace = true </list> I tried a few things but cannot figure out how to integrate it into the trial element. Thanks a lot in advance. Best regards, Leni
	Reply Like 70
Dave	Dave posted 7 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 104K	+x Leni - Friday, January 20, 2017 Hello, I´m currently adapting the Alcohol Dot Probe Script the way I want my experiment to work. I need help on how to compute a variable inter-trial interval. I want the inter-trial trial to vary randomly between the three values 500, 1000 and 1500ms. In the script the inter-trial value is set to 0 ( <values> /iti=0 </values> ) and integrated in the trial via the posttrialpause attribute (/posttrialpause = values.iti) How can I compute the variable inter-trial interval? What I tried so far: Created a list that randomly selects one of the three iti-durations </list itidurations / items = (500, 1000, 15000) /replace = true </list> I tried a few things but cannot figure out how to integrate it into the trial element. Thanks a lot in advance. Best regards, Leni In the <trial> elements, do / ontrialbegin = [values.iti = list.itidurations.nextvalue] i.e., sample a value from the <list> you specified and store it in the global variable values.iti Leave / posttrialpause = values.iti as is.
	Reply Like 79
Leni	Leni posted 7 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 2, Visits: 15	+x Dave - Friday, January 20, 2017 +x Leni - Friday, January 20, 2017 Hello, I´m currently adapting the Alcohol Dot Probe Script the way I want my experiment to work. I need help on how to compute a variable inter-trial interval. I want the inter-trial trial to vary randomly between the three values 500, 1000 and 1500ms. In the script the inter-trial value is set to 0 ( <values> /iti=0 </values> ) and integrated in the trial via the posttrialpause attribute (/posttrialpause = values.iti) How can I compute the variable inter-trial interval? What I tried so far: Created a list that randomly selects one of the three iti-durations </list itidurations / items = (500, 1000, 15000) /replace = true </list> I tried a few things but cannot figure out how to integrate it into the trial element. Thanks a lot in advance. Best regards, Leni In the <trial> elements, do / ontrialbegin = [values.iti = list.itidurations.nextvalue] i.e., sample a value from the <list> you specified and store it in the global variable values.iti Leave / posttrialpause = values.iti as is. Thanks a million for the fast reply! You helped me a lot!
	Reply Like 79