The reason the stim repeat so much is that the paradigm entails switching between two pictures and a blank screen really quickly to create a flicker effect. Since DirectRT doesn't use recursion, I'm just going to have the two pictures and mask in a row such that the subject can jump to a response row at any time. In terms of my old problem, where the screen would not advance until a button press, I think changing the style so that the eligible response times overlap with the time the stimuli is presented will do the trick, though please correct me if I'm wrong.