RATIONALE AND OBJECTIVESFacilitation of detection by clinical history generally has been found with a single abnormality per image but not with multiple abnormalities. Multiple abnormalities per image can occasion a “satisfaction-of-search” effect in which detection of one lesion is reduced in the presence of other distant lesions. Our experiment studied the combined effect of multiple abnormalities and clinical history on accuracy. METHODSDetection of native lesions was measured 1) with histories suggestive of the native abnormality; 2) with these histories and added simulated pulmonary nodules; and 3) with the same added nodules and histories suggestive of metastatic disease. These conditions also were compared with those of a previous experiment that were similar but included no history. RESULTSDetection was substantially improved for appropriately prompted abnormalities even in the presence of a pulmonary nodule. In fact, satisfaction of search vas not found in the presence of an appropriate history. Detection of unprompted abnormalities was unchanged when prompts indicated other abnormalities actually present. Prompted abnormalities were detected earlier in search. CONCLUSIONSHistory appears to direct perceptual resources to the prompted abnormalities, thereby alleviating satisfaction of search. The presence of nodules yielded a small but consistent reduction in total search time for searches involving false responses, suggesting that satisfaction of search may depend more on reduction in search time than had been indicated by previous research.