Help with stop-signal reaction time task

OS (e.g. Win10): Win10
PsychoPy version (e.g. 2024.2.4 Py 3.8): PsychoPy 2025 1.1

What are you trying to achieve?:

I am attempting to create a stop-signal reaction time task in PsychoPy Builder, but I am new to the software and have a few things I can’t figure out how to do. I haven’t been able to find any explanations for these online or on this forum, but if anyone knows of one, please let me know.

  • how do I make a loop continue endlessly, until participants press the correct button 10 times in a row?
  • how do I randomise when a sound stimuli will occur? (i.e., in the main task, some trialsill include a ‘beep’ and others will not). And following on from this, how do I change the keyboard response that is stored as ‘correct’ for these trials with sound to be no key press?
  • How do I randomise the colour of the polygon stimulus? I know how to randomise images, and am using images of circles as a placeholder at the moment, but cannot work out how to randomise the colour of the polygon stimuli themselves.

Sorry for all the questions, I am finding it difficult to find any answers to these elsewhere! Unfortunately I don’t know enough Python to use the coder option, so advice about Builder would be ideal. Any help is much appreciated.

Hello @daisy.s

I think it would be best to read Building Experiments in PsychoPy, see here Resources for teaching and learning — PsychoPy v2025.2.1. You will find the answers to all your questions there, and more besides.

Best wishes Jens