Image flash at the start of a routine

URL of experiment: Cave_v000009 [PsychoPy]

Description of the problem: This happens only online. There is a brief flash of images at the start of a routine (‘chests’) that displays many images that are modified by a mouse click during the course of the routine. The images in the brief flash are enlarged versions of some that show up, by design, later in the routine. I read about other flash problems and tried inserting a blank pause in the loop just before the routine with flashes. I tried moving the code component to the start and to the end of the routine. To no avail. The flashes are most pronounced and reliable in the first use of the routine and less so in later passes. There appears to be no hint of flashing in the local python version. I don’t know what code would be useful to post. Thanks

If you have something set to update every frame then it’s possible that something is going wrong on the first frame. I think lIve experienced one Frame of information from a previous trial unless I reset the contents in Begin Routine first (with the code component above the stimuli).

Please take an example of one stimulus that is flashing and show how its parameters are set and how they change.

I was able to eliminate the flashes by switching to another (more sensible) method of starting & stopping images. I had been manipulating the size so [0,0] was invisible and [.1,.1] was visible. There seemed to be a reason to do that at the time but it’s probably not valid. I am now using the “condition” switch built into images in Builder. I have other problems now but there is no flashing.

I have deleted all the prior attempts to solve the flashing problem to avoid misleading anyone. The message here is - You may want to avoid using size as a way to hide images. It worked fine in python but not online in javascript.