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Jens Bölte	Jens Bölte posted 9 Years Ago HOT Topic Details Share Topic
Group: Forum Members Posts: 78, Visits: 60	Hello, I am programming a dot-probe experiment. Probes will be "F" or "J" and appear either on the left or the right side of the screen. I like to check for the correctness of the answer which I tried to achieve in the following manner. <text probe.right> / items = ("F","F","F","F","F","F","F","J","J","J","J","J","J","J","F","F","F","F","F","F","F","J","J","J","J","J","J","J") / select = noreplace </text> <trial t.pos.word.right> / ontrialbegin = [if (list.posi.probe.pos.right.nextvalue == 1) {text.probe.right.hposition = values.links; values.pos = values.links} else {text.probe.right.hposition = values.rechts; values.pos = values.rechts}] / ontrialbegin = [if (text.probe.right.nextvalue == "F") {values.korrekt = 33} else {values.korrekt = 36}] / stimulusframes = [ 1 = fixation; 30 = maske; 31 = pos.word.right.tar, pos.word.right.dis; 42 = maske; 43 = probe.right] / validresponse = ("F", "J") / iscorrectresponse = [trial.t.pos.word.right.response == values.korrekt] / timeout = 3000 </trial> However, values.korrekt evaluates always to 36 probably because "if(text.probe.right.nextvalue == "F") is always wrong. Suggestions are welcome. Best wishes Jens
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Jens Bölte	Jens Bölte posted 9 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 78, Visits: 60	Hello, I keep on finding a solution. The following seems to work: <list probe.right.l> / items = ("F", "J") / poolsize = 14 </list> <trial t.pos.word.right> / ontrialbegin = [if (list.posi.probe.pos.right.nextvalue == 1) {text.probe.right.hposition = values.links; values.pos = values.links} else {text.probe.right.hposition = values.rechts; values.pos = values.rechts}] / ontrialbegin = [if (list.probe.right.l.nextvalue == "F") {values.korrekt = 33} else {values.korrekt = 36}] / stimulusframes = [ 1 = fixation; 30 = maske; 31 = pos.word.right.tar, pos.word.right.dis; 42 = maske; 43 = probe.right] / validresponse = ("F", "J") / iscorrectresponse = [trial.t.pos.word.right.response == values.korrekt] / timeout = 3000 </trial> Am I mistaken? Best wishes Jens
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Dave	Dave posted 9 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 104K	For stimulus elements (<text>, <picture>, etc.) the nextvalue property is identical to the nextindex property. I.e., what it returns is not the item ("F", "J"), but the item's numerical index (e.g. 1 for the 1st item listed, 17 for the 17th, etc.). Hence your check / ontrialbegin = [if (list.probe.right.l.nextvalue == "F") {values.korrekt = 33} else {values.korrekt = 36} necessarily fails and values.korrekt is always set to 36. Only in for <list> elements do nextvalue and nextindex reflect different things.
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Jens Bölte	Jens Bölte posted 9 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 78, Visits: 60	So, / ontrialbegin = [if (list.probe.right.l.nextvalue == "F") {values.korrekt = 33} else {values.korrekt = 36} as well as / ontrialbegin = [if (text.probe.right.nextvalue == "F") {values.korrekt = 33} else {values.korrekt = 36}] fail? Best Jens
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Dave	Dave posted 9 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 104K	No. As I said in my previous response, nextvalue does what you want in case of <list> elements. It returns the item, not the index number. nextindex returns the index. Another way to fix your code is to use the <text>'s currentitem property in /iscorrectresponse. <text probe.right> / items = ("F","F","F","F","F","F","F","J","J","J","J","J","J","J","F","F","F","F","F","F","F","J","J","J","J","J","J","J") / select = noreplace </text> <trial t.pos.word.right> / stimulusframes = [ 1 = probe.right] / validresponse = ("F", "J") / iscorrectresponse = [if (text.probe.right.currentitem == "F") {values.korrekt = 33} else {values.korrekt = 36}; trial.t.pos.word.right.response == values.korrekt] </trial> <values> / korrekt = "" </values> <block myblock> /trials = [1-28 = t.pos.word.right] </block>
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Jens Bölte	Jens Bölte posted 9 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 78, Visits: 60	Hello, thank a lot. I misunderstood your first reply. Best Jens.
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