Learning from others: effects of viewing another person's eye movements while searching for chest nodules

We report a study that investigated whether experienced and inexperienced radiographers benefit from knowing where another person looked during pulmonary nodule detection. Twenty-four undergraduate radiographers (1 year of experience) and 24 postgraduate radiographers (5+ years of experience) searched 42 chest x-rays for nodules and rated how confident they were in their decisions. Eye movements were also recorded. Performance was compared across three within-participant conditions: (1) free search - where radiographers could identify nodules as normal; (2) image preview - where radiographers were first shown each chest x-ray for 20 seconds before they could then proceed to mark the location of any nodules; and (3) eye movement preview - which was identical to image preview except that the 20 second viewing period displayed an overlay of the real-time eye movements of another radiographer's scanpath for that image. For this preview condition half of each group were shown where a novice radiographer looked, and the other half were shown where an experienced radiologist looked. This was not made known to the participants until after the experiment. Performance was assessed using JAFROC analysis. Both groups of radiographers performed better in the eye movement preview condition compared with the image preview or free search conditions, with inexperienced radiographers improving the most. We discuss our findings in terms of the task-specific information interpreted from eye movement previews, task difficulty across images, and whether it matters if radiographers are previewing the eye movements of an expert or a novice