Visual serach performance during simulated radar observation with and without a sweepline.

A complex vigilance task was used to study the effect of a radar sweepline on attentional processes. The visual display was designed to approximate an automated air traffic control radar display. There were 28 men and women, half assigned to the sweep and half to the no-sweep condition, tested over a 2-h session. Although the no-sweep appeared to be generally superior to the sweep condition in all measures of detection of efficiency, none of the differences was significant. Measures of eye fixation paralleled the patterns of change in performance during the task session. However, as with performance, mean fixation durations for the sweep and no-sweep conditions did not differ, nor were individual differences in scanning activity related to performance. Possible reasons for the lack of relationship between scanning activity and performance are discussed.