Overlooking: the nature of gaze behavior and anomaly detection in expert dentists

The cognitive processes that underly expert decision making in medical image interpretation are crucial to the understanding of what constitutes optimal performance. Often, if an anomaly goes undetected, the exact nature of the false negative is not fully understood. This work looks at 24 experts' performance (true positives and false negatives) during an anomaly detection task for 13 images and the corresponding gaze behavior. By using a drawing and an eye-tracking experimental paradigm, we compared expert target anomaly detection in orthopantomographs (OPTs) against their own gaze behavior. We found there was a relationship between the number of anomalies detected and the anomalies looked at. However, roughly 70% of anomalies that were not explicitly marked in the drawing paradigm were looked at. Therefore, we looked how often an anomaly was glanced at. We found that when not explicitly marked, target anomalies were more often glanced at once or twice. In contrast, when targets were marked, the number of glances was higher. Furthermore, since this behavior was not similar over all images, we attribute these differences to image complexity.