Explains the hierarchic structure of the mammalian visual system. Proposes a model in which feedback pathways serve to modify sensory stimuli in ways that enhance and complete sensory input patterns. Investigates the functioning of the system through computer simulations. (ML)

Hypothesizes that the human brain localizes mental operations which are integrated in the performance of cognitive tasks such as reading. Provides support of this hypothesis from studies in neural imaging, mental imagery, timing, and memory. (RT)

Illustrates how one can discover structure in mental abilities where none was obvious. Reports that two classes of processes are used to form images. Indicates that imagery is carried out by multiple processes, not all of which are implemented equally effectively in the same part of the brain. (RT)