What you described could be done using a combination of your input file and the MinMax field of your styles.drt file.
To be able to record a press of the spacebar for any of the four stimuli in a single series as you described, type
rt: 57
in the time cell for each of the four stimuli. This will tell DirectRT to record any press of the spacebar.
To ensure that the stimulus stays onscreen for 250 ms, you need to make use of the the rows of the styles.drt file, particularly the MinMax field. In the first row of the styles.drt file, type
250!
in the MinMax field. This tells DirectRT that for any stimulus that anything in the .csv input that uses the same number as in the Styles cell of that row of the styles.drt should be displayed for 250 ms and then move on to the next stimulus in the same row of the .csv input file.
Jason Reed
Empirisoft Software Support Specialist