Sustained Operations (SUSOPS) research in the Information Processing Sector at DCIEM tests human ability to work for prolonged periods under harsh conditions, such as sleep deprivation. Subjects perform cognitive tasks as well as others that simulate the position of an operations duty officer in a brigade command post.
NTT Systems developed the testing tasks as well as those used to define and validate experimental protocols, and others used to run, monitor and control the experiment. The original work was done on a PDP-11 system and reimplemented under VAX/VMS. The latter, including upgrades and enhancements, has been the workhorse for SUSOPS research for over ten years.
Eight major experiments, each involving at least sixteen subjects for five days including 64 hours of sleep deprivation have been conducted on this platform.
SUSOPS tasks include mental arithmetic, simple logic puzzles, a test of reaction time and many others. The Subtraction Task, for instance, required the user to repeatedly subtract a constant value from an initial number. The Line Comparison Task placed two lines on the screen, and required the user to guess which was longer. The General Knowledge Task quizzed the subject on general knowledge (e.g.: "What continent is Uruguay on?"). Below is an example of the Logical Reasoning Task, which asked the user to solve a simple problem as quickly as possible: determine the truth or falsity of a statement concerning which of two letters precedes or follows the other. All of these tasks are, of course, relatively easy, but the kind of thing for which our ability degrades considerably when under stress or lacking sleep.
Newer versions of SUSOPS have been developed for PCs, including a portable pen-based computer. The entire system is now being moved over to a networked PC version. The latest versions of SUSOPS include an automated task dispatcher, which allows the experimenter to preprogram a sequence of tasks, complete with rest periods, which will be automatically presented to the subject at their workstation during the actual experiment.