By Kolfers - 11/3/2014
Hi,
I'm trying to build a Useful Field of View Task. One of the requirements is a background like this
: 
As we have very little control over the participants monitors (size, ratio, resolution etc), I'd rather not use an image for this.
I know I can control the canvassize and ratio, but I'm afraid there might still be artifacts from up- or down scaling the image to fit the monitor.
Not to mention the difficulty to line it up with the actual stimuli
Therefore I'd like to use the shape element (either square or circle) and present this at the required positions.
I think ideally that would mean 1 shape element and a list with all the positions. However the following does not work (only presents the shape at one position):
<trial 2>
/ stimulusframes = [1 = shape1, shape1, shape1, shape1;]
/ timeout = 2000
</trial>
I guess it is because the trial loads the shape once, instead of reloading for every presentation?
Of course, I can branch the trial to itself and use a counter, which makes the shape appear at the different positions.
<trial 2>
/ stimulusframes = [1 = shape1;]
/ timeout = 0
/ branch = (if(values.counter < 4) trial.2)
</trial> But then for 64 circles it would over a second to set up the background for every trial (I can't just leave it on screen between trials because other stimuli will overlap it)
I also though of making the background once, take a picture using screencapture and then load that picture on every subsequent trial. But I understood that that
won't work on the webversion (plus I guess there is no way of naming it)
Would you perhaps know a way to tackle this challenge? Or is the only way to create 64 different shapes?
Thank you!
|
By Dave - 11/3/2014
Indeed, the way to do this is to create 64 <shape> elements.
|
|