Radiologists remember mountains better than radiographs, or do they?

Abstract

Abstract. Expertise with encoding material has been shown to aid long-term memory for that material. It is not clear how relevant this expertise is for image memorability (e.g., radiologists' memory for radiographs), and how robust over time. In two studies, we tested scene memory using a standard long-term memory paradigm. One compared the performance of radiologists to naïve observers on two image sets, chest radiographs and everyday scenes, and the other radiologists' memory with immediate as opposed to delayed recognition tests using musculoskeletal radiographs and forest scenes. Radiologists' memory was better than novices for images of expertise but no different for everyday scenes. With the heterogeneity of image sets equated, radiologists' expertise with radiographs afforded them better memory for the musculoskeletal radiographs than forest scenes. Enhanced memory for images of expertise disappeared over time, resulting in chance level performance for both image sets after weeks of delay. Expertise with the material is important for visual memorability but not to the same extent as idiosyncratic detail and variability of the image set. Similar memory decline with time for images of expertise as for everyday scenes further suggests that extended familiarity with an image is not a robust factor for visual memorability.

Memory Effects and Experimental Design

“…Ryan and Hillard, therefore, both found that, at least among experienced radiologists, old and new images can be distinguished from one another better when they contain an abnormality. In our study in 2016, however, we found that radiologistsÕ ability to distinguish new from old chest radiographs did not correlate with the presence or absence of an anatomic abnormality (Evans and Marom, 2016). Only when the material to be remembered was more varied did the fact that an image contain an abnormality result in better memory for that image.…”

“…The sets were to contain those images that each radiologist thought would be easy to recognize, difficult to recognize, or of intermediate difficulty. There was no correlation between the ability of participants to distinguish previously-viewed from new images and the predicted memorability of the images, as judged by the other three (Evans and Marom, 2016).…”

“…This improvement completely disappeared with a gap between study and test phase of an average of 50 days. The radiologistsÕ performance then dropped to chance (50% recognition rate) (Evans and Marom, 2016).…”

“…Immediately afterwards each radiologist was shown another set of 72 images, half of which were randomly selected from the original set of 72 and half of which were new. They were asked to identify the new versus previously-viewed images (Evans and Marom, 2016).…”

“…Further, reducing semantic diversity of visual material by having all the material come from just one semantic category (e.g., doors) also significantly limits mnemonic capacity (Baddeley, 2017). For example, memory scores for recognition of images from one semantic category (e.g., forest scenes) reached only 67% as opposed to a score of 85% for the same number of images originating from four different sematic categories (forest, mountain, cityscape, beach) (Evans and Marom, 2016). Lastly, a related capacity modulating factor to semantic diversity is the level of abstraction of the visual stimulus or rather the lack of availability of stored knowledge about the stimulus.…”