OS (e.g. Win10): Win10
PsychoPy version (e.g. 1.84.x): 2021.2.3
Standard Standalone? (y/n) If not then what?: y
What are you trying to achieve?:
Create a grating stimuli with two arbitrary colors (e.g., red and green).
Conceptually, I’m trying to create a method to determine perceptual isoluminance values for red/green using the minimum motion technique. This requires me to sustain a constant luminance for one color (red) while adjusting the luminance of the other color (green) until there is a change in perceived grating motion – http://wexler.free.fr/library/files/anstis%20(1983)%20a%20minimum%20motion%20technique%20for%20judging%20equiluminance.pdf
What did you try to make it work?:
I’ve referred to this google group thread (https://groups.google.com/g/psychopy-users/c/WQfw2PKUHg4), but I don’t think I follow. Jonathan says “No, I’m afraid that gratings alternating between arbitrary colours does require you to create them yourself using an array or an image. PsychoPy’s grating colours are designed to balance around the mean grey.” What does it mean to create an array – how do I create individual pixels such that some are adjustable?
What specifically went wrong when you tried that?:
I don’t know how to follow the above instructions to create a grating (gabor patch) with two arbitrary colors, such that I can manipulate one of them such that it changes from trial to trial. This has also been referred to as “creating a custom texture” in other posts but I cannot figure out how to apply two different colors to a grating.
I’m attaching a sample stimulus I created, except with incorrect colors.