Are images an important means of recalling information from memory and solving problems? Or are images just display lights on the mind's computer? In Image and Mind, Stephen Kosslyn makes an impressive case for the view that images are critically involved in the life of the mind. In a series of ingenious experiments, he provides hard evidence that people can construct elaborate mental images, search them for specific information, and perform such other internal operations as mental rotation. Kosslyn demonstrates that these results are best explained by a two-tiered model in which...