Yesterday I linked to Edward Adelson’s checkershadow illusion. I was mosying around his papers page looking for a paper with a description of (or better a picture or) that illusion, largely because in some circumstances it’s better to refer to papers than websites. (Not online obviously!)

I didn’t find what I was looking for, but I did find a bunch of other interesting papers on illusions. And most of them have lots of pretty pictures. (Though honestly I only read the articles for the, er, articles.) I was particularly impressed by the snake illusion in his Lightness Perception and Lightness Illusions. It’s a nice example of an illusion that doesn’t turn on immediate contrasts, since the illusory diamonds have the same immediate contrast. As Adelson puts it, it’s as if we can turn contrast effects on and off by ‘remote control’.

Every time I look at perception I’m struck by just how big a mystery it is.