I was wondering whether one could implement the following using when:
say a subject is presented with a fast event-related design with randomized inter-trial-intervals. Moreover, what is of interest is the thinking time before making a response. For example, lets say a trial starts at time 120 seconds into the run and the subject deliberates until 122.6 seconds and then makes a response. I am interested in creating a reference function that "turns the regressor on" between 120-122.6 seconds and leaves is "off" otherwise. Finally, if there are several different conditions, I would like to turn these individual regressors "on" or off based on the subject's data.