Probabilistic Feedback

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Probabilistic Feedback

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wessa	wessa posted 9 Years Ago Topic Details Share Topic
Group: Forum Members Posts: 2, Visits: 8	Hi, in a learned helplessness task I would like to insert a probabilistic feedback after a response is given by the subject, i.e. a feedback that is not contingent to the accuracy of the response. More precisely, the subject should receive a "punishment" feedback (in our case waiting for 12 sec until the next trial starts) in 75% of the trials and a "reward" feedback (waiting for only 2 sec until the next trial starts) on 25% on the trials but always irrespective of the correct or incorrect answer the subject has given. Any idea on how I could implement that in the script? Is there any option by using the select attribute? Or by using a counter? If yes, how would I concretely write it in the script? Thanks a lot for your help and looking forward to hopefully quick answers, Michèle
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Dave	Dave posted 9 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	You can, for example, enter your "punish" and "reward" trials into a <list> in the desired proportions and then /branch from your "main" trial(s): <block myblock> / trials = [1-100=mytrial] </block> <trial mytrial> / stimulusframes = [1=mytext] / validresponse = ("d", "k") / correctresponse = ("k") / branch = [list.feedbacklist.nextvalue] </trial> <trial punishment> / stimulusframes = [1=punishtext] / validresponse = (0) / trialduration = 12000 </trial> <trial reward> / stimulusframes = [1=rewardtext] / validresponse = (0) / trialduration = 2000 </trial> <list feedbacklist> / items = (trial.punishment, trial.reward) / poolsize = 100 / itemprobabilities = (.75, .25) </list> <text mytext> / items = ("Press D or K") </text> <text punishtext> / items = (":( Wait for 12 seconds.") </text> <text rewardtext> / items = (":) Wait for 2 seconds.") </text>
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wessa	wessa posted 9 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 2, Visits: 8	Thanks a lot Dave, that helped a lot. Best, Michèle
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