Perceiving in a Blink of an Eye, Its Role in Visual Awareness and Why One Should Care

Abstract: Visual awareness of everyday complex environments involves both the individuation and recognition of objects and rapid extraction of global image properties of the scene. Humans have rapid access to global structural and statistical regularities which allows them the extraction of the “gist” or meaning of an image, central to the efficient assessment and orienting in complex environments. This ability is based on our extensive experience with the regularities of the natural world. Radiological images can be thought of as a specialized class of scenes and radiologists are experts who have learned to tune their visual system to regularities in these unusual scenes. Consequently, we have found that the gist of the abnormal in radiographs, viewed only for half a second, allows radiologists to detect the presence of disease independent of the locus of any lesion and up to 3 years before the onset of cancer. I will address the nature of the gist signal in natural and radiological images and what affords humans the ability to detect it. I will speak on how this expertise can be trained as well as ways to refine the screening of medical images and inform and enhance the capabilities of computer-based detection systems to save lives.