Millisecond Forums

Hi all,

I've been working on an experiment in which participants have to respond by pushing or pulling a joystick. In order to continue to a next trial, participants have to pull the joystick completely towards themselves. However, the size of a stimulus on the screen should gradually increase while pulling the joystick, creating some sort of zoom-effect. My plan was create a block that starts out with a trial in which the size of the stimulus is average. If a participants responds by pulling the joystick to the 25-threshold, the next trial, in which the size of the stimulus is increased, automatically starts (using the "/branch" attribute). In that trial, the participant continues pulling the joystick, and upon reaching the 50-threshold, the following trial starts (again with a larger stimulus), and so on untill they reach the 75 and the 100-threshold. When participants reach the 100-threshold, a following block starts. The total reaction time can then be calculated by summing the RT's for the entire block. (Note that, technically speaking, I would use blocks as trials and trials as stimuli, if that makes sense :o) )

The question is pretty easy: Is this possible in Inquisit (2 or 3, doesn't really mather)? I've tried programming the experiment in the way I just described, but one important problem seems to be that the "/joystickthreshold" attribute has to be defined in the defaults, and can not be redefined on a trial-by-trial basis. Any suggestions?

Thanks in advance!

Bram

Hi Bram,

Alas, joystickthreshold is not a dynamic property that can be changed mid-experiment. It wouldn't be hard to add this feature, however, so I can try to sneak it into the next update. That would be a few months away, however.

Regards,
Sean

Hi Sean,

Is there no other way to get past this problem? I really need this feature too, preferably within 2 weeks : ) Do you have suggestions to create a kind of 'zoom'-effect in Inquisit in another way?

Best,

Tessa