Expert radiologists have improved memory performance for images with focal abnormalities

Memory capacity depends on prior knowledge, both in working memory and in long-term memory. For example, radiologists have improved long-term memory for medical images compared to novices. Furthermore, people tend to remember abnormal or surprising items best. This is often claimed to arise primarily because such items attract additional attention at encoding. How do expertise and abnormality interact when experts are actively searching for abnormalities; e.g. radiologists looking at mammograms? In the current work, we investigate whether expert radiologists (N=32) show improved memory performance for abnormal images compared to novice participants (N=60). We consider two types of “abnormality.” A mammogram can have a focal abnormality that can be localized or it could simply be the mammogram of a woman known to have cancer (e.g. the image of the breast contralateral to the focal abnormality). Must an image have a focal abnormality for additional attentional processing to be engaged? We found that experts have better memory for mammograms than novice participants and enhanced memory for abnormal images relative to normal images. Overall, radiologists showed no memory benefit for the contralateral-abnormal images and did not discriminate them from normal images, but had enhanced memory for images with focal abnormalities. Our results suggest that focal abnormalities play an important role in enhancing memory of expert observers.