Chance Discovery in Image Diagnosis: - Analysis of Perceptual Cycles -

Image diagnosis is the task in which a physician searches for abnormal findings on the medical images that potentially involve a large amount of anatomical and pathological information, and identifies diseases from such findings. Since this task aims to reduce the risk (e.g., insult or death) that will occur in the near future, it can be seen as a case of chance discoveries. To investigate the cognitive process underlying the task, we conducted an experiment in which two independent physicians diagnosed the same CT images. Analysis of disagreements about final diagnosis and verbal protocols revealed that when observing the CT images on which one disagreed with the other, the physicians engaged in iterative cycles of the image-feature search and the schema construction. The result suggests the importance of investigating cyclic interactions between humans and environments when considering chance discovery.