Functional specialization is a property of biological systems generally. A unifying theme that cuts across all research areas and techniques in the cognitive and brain sciences is whether there is specialization of function at levels of processing that are ‘abstracted away’ from sensory inputs and motor outputs. The articles collected together within this issue advance our understanding of the roles of modularity and functional specialization in deriving inferences about the structure of the mind from behavior in normal and brain damaged individuals, functional neuroimaging, computational modeling, development, and the study of individual differences.