The contributions to this volume, the sixteenth in the prestigious Attention and Performance series, revisit the issue of modularity, the idea that many functions are independently realized in specialized, autonomous modules.Although there is much evidence of modularity in the brain, there is also reason to believe that the outcome of processing, across domains, depends on the synthesis of a wide range of constraining influences. The twenty-four chapters in Attention and Performance XVI look at how these influences are integrated in perception, attention, language comprehension, and motor control. They consider the mechanisms of information integration in the brain; examine the status of the modularity hypothesis in light of efforts to understand how information integration can be successfully achieved; and discuss information integration from the viewpoints of psychophysics, physiology, and computational theory.A Bradford Book. Attention and Performance series.