Frame not drawing properly


I have an image, that i rotate in the ‘Begin Routine’ section that I then interchange with another image every 0.5 seconds. I do this for about 10 seconds. I noticed that sometimes the frame does not proceed in the order mentioned and i notice ghost images in the incorrect order. I checked the time. It is supposed to run for 10 seconds and it runs exactly 10 seconds. But what can i do to ensure the ghosting (because the image did not rotate in time) does not happen i.e. it rotates itself and shows up for the job in its allocate 0.5th second?


It only happens in the online version and it looks like it is the first frame only. The draw on the first frame is shorter than the rest, not allowing all the instructions to complete before the draw call , perhaps? I don’t know how to explain it better just yet.

Fixed. Cut down as much drawing in the ‘Begin’ section. Moved textstim creation code earlier into the ‘Experiment’ section.