By Lucie1043 - 12/22/2015
Hi,
I am running an experiment that shows a picture in the middle of the screen. The participant has to click X times on this picture in order to have access to a subsequent task.
I would like the size of the picture to be divided by half every time the participant clicks on it.
Do you have any idea on the way to configure that?
Thank you,
Lucie
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By Dave - 12/22/2015
The /size attribute accepts variables (<values> entries), i.e. you can simply set those to the desired value after each click using /ontrialend logic.
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By Dave - 12/22/2015
Example based on the previous ones I gave you in another thread:
<values>
/ aclickcount = 0
/ arequiredcount = 1
/ ahpos = 0%
/ bhpos = 0%
/ asize = 40%
</values>
<expt>
/ blocks = [1-4=choiceblock]
</expt>
<block choiceblock>
/ onblockbegin = [if (block.choiceblock.totalcount > 0) values.arequiredcount = 2 * values.arequiredcount; ]
/ trials = [1-10=choice]
</block>
<trial choice>
/ ontrialbegin = [if (values.aclickcount <= 0) {values.ahpos=list.indicehposition.nextvalue; values.bhpos=list.indicehposition.nextvalue; values.asize=40%}; ]
/ ontrialend = [if (trial.choice.response=="astim") {values.aclickcount+=1; values.asize=values.asize*0.5; }; ]
/ stimulusframes = [1=astim, bstim, debug]
/ validresponse = (astim, bstim)
/ inputdevice = mouse
/ branch = [if (trial.choice.response=="bstim") trial.b]
/ branch = [if (trial.choice.response=="astim" && values.aclickcount>=values.arequiredcount) trial.a else trial.choice]
</trial>
<list indicehposition>
/ items = (25%, 75%)
/ selectionrate = always
</list>
<trial a>
/ ontrialend = [values.aclickcount=0]
/ stimulusframes = [1=mytext, debug]
/ validresponse = (57)
</trial>
<trial b>
/ ontrialend = [values.aclickcount=0]
/ stimulusframes = [1=mytext, debug]
/ validresponse = (57)
</trial>
<text astim>
/ items = ("A")
/ txbgcolor = (blue)
/ vposition = 50%
/ hposition = values.ahpos
/ size = (values.asize, values.asize)
</text>
<text bstim>
/ items = ("B")
/ txbgcolor = (green)
/ vposition = 50%
/ hposition = values.bhpos
/ size = (40%, 40%)
</text>
<text mytext>
/ items = ("<%script.currenttrial%>")
</text>
<text debug>
/ items = ("A clicks required: <%values.arequiredcount%> | A clicks made: <%values.aclickcount%>")
/ position = (50%, 10%)
/ erase = false
</text>
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