The style file was located in the same folder as my input file, and, using the method you proposed, I discovered the file was not being changed when I edited it through Edit > Edit Default Styles > Options in the DirectRT window. What I had to do was open up the style file directly from a Windows explorer window, and from there I was able to change the resoultion for the experiment, so now my display times for the experiment are lower. I am still seeing a flash on the screen, however, and have tried the fixes proposed here on the forum and in the help files, and I'm starting to think that I have reached the hardware limit of the system DirectRT is installed on, though I'm open to any other ideas.