Mechanism of satisfaction of search: eye position recordings in the reading of chest radiographs.

PURPOSE

To use the eye position recordings of observers as they read chest images to advance understanding of the mechanism of "satisfaction of search," a phenomenon in which the detection of one abnormality interferes with the detection of other abnormalities.

MATERIALS AND METHODS

Eight radiologists examined chest images that contained simulated pulmonary nodules and native abnormalities. Accuracy in detecting nodules and native abnormalities and eye position, gaze duration, and total search time were recorded.

RESULTS

Nodule detectability was lower on native abnormality-containing images than it was on normal images (P < .005). Native-abnormality detectability was not negatively affected by the nodules. Most missed nodules were fixated; only those on images without native abnormalities, however, received prolonged visual attention.

CONCLUSION

The satisfaction of search phenomenon is an important source of error in the detection of subtle abnormalities but not of obvious abnormalities. Obvious abnormalities capture visual attention and decrease vigilance for more subtle abnormalities.