Dear Rick,
No, it's indeed a single fMRI run with ~18 minutes continuous data acquisition. Actually this is a rather short one, there have been experiments with session lengths of up to 45 min at that scanner. Not sure whether scanner drift is the major drawback then, probably it's more of an issue for the subject, as 30 min can be very long without any indication from outside for how much time has already passed, which might lead to frustration and affect behavioral scores & activation, leaving aside head motion.
Best
Helmut
Edited 1 time(s). Last edit at 06/17/2015 01:58PM by Helmut.