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Abstract
Cancer diagnosis frequently relies on the interpretation of medical images such as chest X-rays and mammography. This process is error prone; misdiagnoses can reach a rate of 15% or higher. Of particular interest are false negatives-tumors that are present but missed. Previous research has identified several perceptual and attentional problems underlying inaccurate perception of these images. But how might these problems be reduced? The psychological literature has shown that presenting multiple, duplicate images can improve performance. Here we explored whether redundant image presentation can improve target detection in simulated X-ray images, by presenting four identical or similar images concurrently. Displays with redundant images, including duplicates of the same image, showed reduced false-negative rates, compared with displays with a single image. This effect held both when the target's prevalence rate was high and when it was low. Eye tracking showed that fixating on two or more images in the redundant condition speeded target detection and prolonged search, and that the latter effect was the key to reducing false negatives. The redundancy gain may result from both perceptual enhancement and an increase in the search quitting threshold.
Keywords Visual search . Selective attention . Eye movements . Visual attention
Many routine activities involve visual search, such as finding your car in a busy parking lot or searching for a product on a website. Visual search tasks can have far-reaching consequences in the real world. Professionals engage in visual search during important tasks such as screening for weapons in airport luggage or detecting abnormalities in medical images. Although models developed from simpler laboratory displays are useful (Drew, Evans, Vö, Jacobson, & Wolfe, 2013), applied tasks pose unique challenges. Of particular interest here are medical images, which are typically complex, involving the detection of subtle tumor signals not well segmented from the background. In some situations, such as routine cancer screening, the occurrence rates of tumors are low, creating a "low-prevalence" scenario that increases decision errors (Evans, Tambouret, Evered, Wilbur, & Wolfe, 2011). Image ambiguity, low target prevalence, inattention, and other factors contribute to errors in medical image perception, as well as in laboratory studies using visual search (Wolfe, Evans, Drew, Aizenman, & Josephs, 2016). In routine cancer screening, the errors are largely false negatives, in which...