Timing Issues: Picture Overlapping with Fixation Despite Correct Settings

Builder
1

OS (e.g. Win10): Win 10
PsychoPy version (e.g. 1.84.x): 2024.2.0
Standard Standalone? (y/n) :y
What are you trying to achieve?: I’m trying to present pictures immediately after a fixation cross disappears. The pictures should not overlap with the fixation, but in my experiment, they appear to overlap. I’m unsure whether this is caused by an issue with my timing settings, as the fixation duration is quite short and the pictures are set to appear right after it disappears, or if there might be a bug in PsychoPy causing this behavior.

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What did you try to make it work?: I’ve tried setting specific start and end times for the fixation and pictures rather than using a duration for the fixation’s Stop value. However, this leads to the fixation not showing consistently.

What specifically went wrong when you tried that?: no error messages appear.

I attached the experiment(called ‘only_learn.psyexp’) below so you can test it. timing_issues.zip - Google Drive

2

The start time of fix_cross is set to 0 s, with a duration of 0.25 s. I believe this setting is appropriate. I have tested the timing and found that even if I change the start times of objects 1, 2, 3, and 4 to 1 s,fix_cross still overlaps with these objects.

3

I’ve just done some investigation and discovered that the issue is that your image files are too large. For every trial you have four images which are all 2400 x 2400 pixels. For comparison my screen is 1920 x 1080 pixels.

Here are some videos (using ShareX) of a test version using your images and then your images resized to 1000 x 1000 pixels (which is still much more than you need — 500 x 500 would be sufficient.

Original files

Original files (sound disabled)

Images 1000 x 1000 pixels (sound reenabled)

4

thanks! adjusting the size of the images actually solved the problem