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Cannot set a Prime image in a stop signal task on Pavlovia

URL of the experiment: Pavlovia

Description of the problem: @wakecarter @dvbridges @jon I have designed a stop signal task (green circle as the stop signal) with 4 blocks. It also has a prime image (facial expressions) which come up after the fixation. However, the prime image is not set during the trials in Block 1 although it is present in the HTML resource folder.

Any way to resolve this?

Please be more specific.

Are you getting an error or is the screen just blank?

Please show screenshots of the relevant components and code.

Hello @wakecarter,

This is the sequence of the routine: fixation, prime (face image) on all trials, go signal with X or N, stop signal with a green image on some trials, key response on go trials.

I am able to see the stop signal i.e. the green image but the prime face image is not visible. I have left the ‘image’ property of the Prime1 component blank. There is no error message i.e. the trials run till the block ends. This is the code I am running in the ‘begin routine’ of code1 component:


I am not able to narrow down the issue here.

Try print(trialN, emo1[trialN], eFace[emo1[trialN]-1]) to see if the variables are as expected.

Looks like this:


Hi @wakecarter,

Could you please suggest something? I am still not able to figure this out.

Does it work if you increase the duration of the prime image?

No, I increased it by 500 ms and 1000 ms to check. But, it did not work.

I don’t have any more suggestions that come to mind, but I’d be happy to delve in deeper if you’d like to commission me to fix that bug.

Okay. Just one last query. Could it be related to the ‘.setAutoDraw’ function of the prime image and the stop signal?

I can’t see you setting autoDraw for the prime image in your code.

However, I agree that it could be that.

I would either

  1. set the start and stop times in the image components or
  2. not have image components in this routine and then start and stop using autodraw in code or
  3. have image components which start at the beginnig of the routine and you show or hide by either changing the image, size, location or opacity.