Visual search patterns and experience with radiological images.

Eye movements of 24 subjects, including untrained laymen, medical students, radiology residents, and staff radiologists, were recorded while the subjects viewed normal and abnonnal chest radiographs. Evolution of search patterns from the localized central pattern of the untrained observer to the circumferential pattern of the radiologist is discussed. It is postulated that development of the pattern is secondary to development of knowledge about the location and characteristic features of normal and abnormal. Improvement in search patterns comes about as a result of concentrating on clearly defining the abnormal feature that is the object of search and the normal background that envelops it.