Description of the problem: I am trying to create a stimulus in which two semi-transparent gratings are presented on top of each other and drift in different directions (one drifts upwards and the other drifts downwards) creating an impression of a fade. Can psychopy do this? It’s for my MSc in psychology.
This should be possible, yes! In Builder view, check out the Grating component - it has an attribute opacity which allows you to make it semi-transparent.
why do you call it flicker in the title and drift in the question body? Marc Green’s work back in 1983 used those terms separately