The influence of a perceptually linearized display on observer performanceand visual search

Rationale and Objectives, The purpose of this study was to determine whethe r perceptual linearization of the tone scale affects the detection and visu al search behaviors of radiologists searching mammograms for masses and mic rocalcifications. A perceptually linearized display is designed to match th e capabilities of the human visual system more closely than a nonlinearized display. Materials and Methods. Six radiologists viewed 50 pairs of mammograms, once on a perceptually linearized cathode-ray tube (CRT) monitor and once on a nonlinearized CRT monitor. Eye position also was recorded as the observers searched the images for masses and microcalcifications. Results. Observer performance was significantly (P = .003) better with the perceptually linearized display. Dwell times associated with true-negative decisions were significantly longer with use of the nonlinearized display. The number of fixation clusters generated during search was also greater wi th use of the nonlinearized display for the lesion-free images. Conclusion, A perceptually linearized display yields better detection perfo rmance and a more efficient visual search. Perceptually linearized displays should be used for reading radiographs displayed on CRT monitors.