"Flashes" between tasks

Dear Lisa,

I have tried to set up what you describe (I used the code from the endo-exo attention cueing which features fix-points animation made up from 4 images of cross getting bigger and bigger). The code goes as following (I have cut stuff before and after this part of the code):

task exogenous
keys kp5 kp4 kp8 kp6 kp2
##############################################
show bitmap fixpoint1
delay 150
show bitmap fixpoint2
delay 150
show bitmap fixpoint3
delay 150
show bitmap fixpoint4
delay 150

I thought the problem could be that the animation is maybe different in each frame (the center of the cross, however big it is is featured in the same position so the flash is maybe masked by this) so I used different bitmaps:

task endogenous
keys kp5 kp4 kp8 kp6 kp2
##############################################
show bitmap press5
delay 150
show bitmap happy
delay 150
show bitmap sad
delay 150
show bitmap fixpoint4
delay 150

and got the same result: I did not see a flash, that is all of the pictures ran smoothly one over another. However, since the press5 was the biggest image I noticed that I did not clear it and then I tried to clear it thinking maybe this caused a flash. Even after clearing it, the images ran smoothly... I tried changing the resolution of the experiment - still good.

I am viewing the experiment from the Mozilla browser and my screen resolution is 1920x1080 (if this could in any way be related with the problem). Also, maybe the images are too large to be quickly screened by the Psytoolkit (I tried to replicate Your problem by using small fixpoints and smiley faces).

Prof. Stoet will definitively provide You with the better answer (I am also a beginner in this and had some difficulties of my own) but maybe this will also help You a bit

Best, Matia