I'm currently using Psychtoolbox to attempt to write a visual task on top of a video background, and looking at EEG patterns and response times. I'm currently attempting to adapt the Demo function "DetectionRTInVideoDemo" to do this and not having much luck. Could anyone tell me if there is a way to either 1. create a transparent screen where stimuli can be placed while still viewing the video underneath, or 2. placing small pictures (e.g. small circles) over top of the texture at certain times in the video?