Millisecond Forums

As always, thank you, Dave.
Best,
nakayama

Hi, Dave. 
I am wondering whether it is possible to track the position of the target, and erase it at random stimulustime, given that its position and onset varies randomly?  
So that they can appear and be erased randomly.
I guess should I use ontrialbegin? Thank you.

<list erase>
/ items = (2500,2600,2700,2800,2900)
/ selectionmode=random
/ selectionrate = always
</list>

<list targetduration>
/ items = (2100,2200,2300,2400,2500)
/ selectionmode=random
/ selectionrate = always
</list>
<trial timepresent1>
...
/ ontrialend = [trial.timepresent1.resetstimulusframes(); list.targetduration.reset(); ]
</trial>  

             

Yes, and it works exactly like what you've already done. You've used the insertstimulustime() function to display your target(s) at a random onsets. You only need to do the exact same thing for the stimuli that erase the respective target(s).

Thank you for your reply. It works when the position of stimulus was set fixed. However, when the position was set according to a list:

...
/hposition=list.hpos1.nextvalue
/vposition=list.vpos1.nextvalue

How should I set the position of
if I want to erase shape 1?
It didn't erase shape1 if I input:

/hposition=shape.1.hposition
/vposition=shape.1.vposition
And input insertstimulus(shape.erase,list.eraseduration.nextvalue) under the same ontrislbegin with shape1

Store positions etc. in global variables (<values> entries), reference those as needed:

<values>
/ s1h = 0
/ s1v = 0
/ s1onset = 0
/ s1duration = 0
/ s2h = 0
/ s2v = 0
/ s2onset = 0
/ s2duration = 0
</values>

<list onsets>
/ items = (2000,2500,3000,3500,4000,4500)
/ selectionrate = always
</list>

<list duration>
/ items = (100,200,300,400,500,600)
/ selectionrate = always
</list>

<list h>
/ items = (20%, 40%, 60%, 80%)
/ selectionrate = always
</list>

<list v>
/ items = (20%, 30%, 40%, 50%, 60%, 70%, 80%)
/ selectionrate = always
</list>

<block someblock>
/ trials = [1-10=sometrial]
</block>

<trial sometrial>
/ ontrialbegin = [values.s1h=list.h.nextvalue; values.s1v=list.v.nextvalue;
    values.s1onset=list.onsets.nextvalue; values.s1duration=list.duration.nextvalue;

    values.s2h=list.h.nextvalue; values.s2v=list.v.nextvalue;
    values.s2onset=list.onsets.nextvalue; values.s2duration=list.duration.nextvalue; ]
/ ontrialbegin = [trial.sometrial.insertstimulustime(shape.s1, values.s1onset);
    trial.sometrial.insertstimulustime(shape.e1, values.s1onset+values.s1duration);

    trial.sometrial.insertstimulustime(shape.s2, values.s2onset);
    trial.sometrial.insertstimulustime(shape.e2, values.s2onset+values.s2duration); ]

/ ontrialend = [trial.sometrial.resetstimulusframes(); list.h.reset(); list.v.reset(); list.duration.reset(); list.onsets.reset(); ]

/ stimulusframes = [1=info]
/ validresponse = (57)

</trial>

<shape s1>
/ shape = rectangle
/ color = red
/ size = (100px, 100px)
/ hposition = values.s1h
/ vposition = values.s1v
</shape>

<shape e1>
/ shape = rectangle
/ color = white
/ size = (100px, 100px)
/ hposition = values.s1h
/ vposition = values.s1v
</shape>

<shape s2>
/ shape = circle
/ color = green
/ size = (100px, 100px)
/ hposition = values.s2h
/ vposition = values.s2v
</shape>

<shape e2>
/ shape = circle
/ color = white
/ size = (100px, 100px)
/ hposition = values.s2h
/ vposition = values.s2v
</shape>

<text info>
/ items = ("S1: Onset = <%values.s1onset%> | Duration = <%values.s1duration%> | X = <%values.s1h%> | Y = <%values.s1v%>
~nS2: Onset = <%values.s2onset%> | Duration = <%values.s2duration%> | X = <%values.s2h%> | Y = <%values.s2v%>")
/ position = (50%, 5%)
/ erase = false
/ size = (90%, 5%)
</text>

Thank you Dave! this scrip helped a lot!