Display of stimuli

Online experiments
1

Hi there

I have a couple of experiments that do not behave as expected when I run them on Pavlovia. I am using PsychoPy version 2024.2.3. Unless I set all stimuli to a fixed duration, some stimuli are not displayed or are skipped. For example, the typical sequence I use is fixation cross, word stimulus. The response ends the routine. Without a fixed display duration and a fixed reaction duration, the fixation cross is not displayed. However, a fixed timing makes the experiment “awkward”. The fixed duration of the trial creates a rhythm in the experiment that I would like to avoid. I suspect that this is due to the version I am using, as earlier versions did not show this behaviour.

Do you have any suggestions as to which version to use or how to resolve this issue? A fixed routine duration has not really helped. Please note that I use embedded surveys in my experiments.

Thanks in advance.

Best wishes, Jens

2

There is a problem with t (routine timer) in 2024.2. This is now fixed in the dev version but the workaround I’ve been using in the current release is to set up a custom clock. However, this doesn’t help with components set to start after the routine start unless you also control them with the clock. Here’s Each Frame code from an experiment I’ve been working on.

mouseloc = mouse.getPos()
if myClock.getTime() > 2: # End on 2 seconds
    continueRoutine = False
elif myClock.getTime() > 1 and fixation.text == '': # Hide square and display fixation (for next trial) after 1 second
    fixation.text = '+' 
    target_square.setPos([2,2])
# following code is related to touchscreen response
elif mouseloc[0]==mouserec[0] and mouseloc[1]==mouserec[1]: 
    pass
elif blue_circle.contains(mouse) and rt == 0:
    blue_circle.setFillColor(bluer)
    rt = round(myClock.getTime()*1000)

Alternatively, for your fixation cross issue, could you put it in a prior routine? I couldn’t above because I wanted to capture responses after the square had disappeared.

If you have VS code (or similar) then you could try running from the latest release or dev branch, or you could set version to 2024.1.4.

3

Hello @wakecarter

Thanks a lot for the info and the code. Moving the fixation cross to a different routine did not help. I switched back to version 2024.1.4. which helped.

I hope that this will be fixed soon as this is a basic function.

Best wishes Jens