Screen randomly turning gray for some participants

Online experiments
1

URL of experiment: https://run.pavlovia.org/ctaher/atonalmusictimeexp/html

Description of the problem: Some participants are reporting the screen turning gray after completing several experimental trials (no problems with the initial demographic questions or practice trial—which is identical to the experimental trials). They seem to be able to make responses (and see their responses), but no longer able to see the questions (most of them in slider form, except for one that they weren’t able to see either). I know one participant was running the experiment on MacIntel and Chrome, and another one was on Windows10.
I have run the experiment several times on every possible browser using MacOs 10.14.6 without any problems, and participants using Windows32 seem to be able to complete the experiment without issues.
I would be very grateful if you could please help me figure out what the issue could be.
Many thanks!

2

This sounds like a memory issue. Do you have any components updating every frame?

3

Thank you so much! Yes, the slider position is being displayed as text and that needs to be updated every frame. Participants are still able to see this text though (only the slider labels are disappearing). Could you please help me?

4

The slider position shouldn’t be updated on frames where it doesn’t change. Save the old value and only set the value on the screen if it’s different.

5

Thank you very much for all your help! Sorry I am confused (my programming skills are very basic). I am only saving the final slider-position value (for each routine). I need the participants to see the slider-position value every time they move the slider knob (within the same routine). This is why I thought I needed to update a text component (that displays the slider-position value) on every frame.
My code component looks like this:
Begin routine: text_ExpTotalDurResponse.text = ‘’ (JS); text_ExpTotalDurResponse.text = null; (Py)
Each frame: text_ExpTotalDurResponse.text = slider_ExpTotalDurQ.markerPos (JS and Py)
where text_ExpTotalDurResponse is an empty text component.

I would be very grateful if you could help me figure out how to fix the problem. A million thanks for your time!

6 
if slider_ExpTotalDurQ.markerPos != oldMarkerPos:
     text_ExpTotalDurResponse.text = slider_ExpTotalDurQ.markerPos
     oldMarkerPos =  slider_ExpTotalDurQ.markerPos
1 Like
7

A million thanks! I have modified the code and run the experiment (on my computer) without problems. I will post again here once I can confirm the problem has indeed been solved (the experiment always ran fine on my computer, so now I need to wait and see if some participants are still having issues).
Many thanks for all your help. I immensely appreciate your time! HUGE THANK YOU!
:grinning: :clap:

1 Like
8

I would like to thank the Psychopy Team, especially @wakecarter, once again for all their help and support. My experiment seems to be running smoothly on many different machines now! A MILLION THANKS! :grinning: :clap: