Image intensity variations can result from several di erent object surface e ects, including shading from 3-dimensional relief of the object, or paint on the surface itself. An essential problem in vision, which people solve naturally, is to attribute the proper physical cause, e.g. surface relief or paint, to an observed image. We addressed this problem with an approach combining psychophysica...

(1809-49)-American poet, short-story writer, and critic who is best known for his tales of ratiocination, his fantastical horror stories, and his genre-founding detective stories. Poe, whose cloudy personal life is a virtual legend, considered himself primarily a poet. William Wilson (1839)-A tale about a man's struggle with his conscience — an allegory in which William Wilson meets William Wil...

There are times when something is simply so familiar that we can no longer see it at all. It can be a story, or a concept, or even a flesh-and-blood person. Familiarity breeds not only contempt, but a kind of invisibility as well. For too many of us, such is the case with Sir William Osler. In his time (1849–1919), many considered him to be one of the greatest practitioners, teachers, and write...