Dynamic Comprehension: Time on Position And Mental Fatigue
Larry Bailey, Ph.D. (PDF)

The ATO needs to know how long it takes a controller to develop dynamic comprehension (often called Situation Awareness) after taking over a position in today�s environment. Furthermore, the ATO needs to know how long a controller can maintain dynamic comprehension before suffering degradation in his/her ability to monitor and/or control traffic.

Because the results of FY09 research demonstrated that technology was not sufficiently advanced to be able to reliably measure changes in dynamic comprehension on the order of seconds (which was a requirement for this research), research will focus on determining the maximum amount of time a controller can be on position before experiencing degradation in cognitive performance sufficient to affect air traffic control performance. This research is in line with what is commonly referred to in the fatigue literature as �time on task fatigue.�

There are three research objectives:
  1. Identify measures sensitive to changes in dynamic comprehension that occur following a position transfer,
  2. Determine the minimum amount of time on position that a controller needs to develop dynamic comprehension, and
  3. Determine the maximum amount of time a controller can work on position before suffering a degradation in dynamic comprehension.
All objectives will be accomplished within a simulated en route air traffic control environment.

Objectives 1 and 2 were accomplished and reported in the end of year report for FY09. Objective 3 has been expanded to include the following:
  1. Identify physiological markers of time on task fatigue,
  2. Identify cognitive decrements associated with time on task fatigue while performing air traffic control activities,
  3. Identify maximum time a controller can be on position before experiencing decrements in cognitive performance that impacts CPCs� operational performance,
  4. Determine break duration necessary to recover from time on task fatigue, and
  5. Identify break activities that may impede or enhance time on task recovery.