This work integrates a twenty-year research program on the nature of high-level vision and mental imagery. It marshals insights and empirical results from computer vision, neuroscience, and cognitive science to develop a general theory of visual mental imagery, its relation to visual perception, and its implementation in the human brain. It offers a definitive resolution to the long-standing debate about the nature of the internal representation of visual mental imagery. The author reviews evidence that perception and representation are inextricably linked, and goes on to show how "quasi-pictorial" events in the brain are generated, interpreted, and used in cognition. The theory is tested with brain-scanning techniques that provide stronger evidence than has been possible in the past. Known for his work in high-level vision, one of the most empirically successful areas of experimental psychology, the author uses a highly interdisciplinary approach. He reviews and integrates an extensive amount of literature in a coherent presentation, and reports a wide range of new findings using a host of techniques.