Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2007.Includes bibliographical references (leaves 139-145).This thesis examines two questions concerning the working memory system underlying language processing: (1) To what extent is the working memory system underlying language processing domain-specific? and (2) What is the relationship between the working memory system and the long-term memory system in language processing? In Chapter 1, I describe ten experiments investigating the extent to which the working memory system underlying linguistic integrations is domain-specific. I argue that the results of these experiments demonstrate that at least some aspects of the working memory system used for linguistic integrations are not domain-specific, being involved in arithmetic, and possibly, musical processing. In Chapter 2, I describe six experiments investigating the relationship between the two retrieval operations that are required when an incoming word is integrated into an evolving structure: the retrieval of the lexical properties of the word from long-term memory and the retrieval of its structural dependents from working memory. I demonstrate that the relative ease or difficulty of retrieving the lexical properties of an incoming word affect the difficulty of retrieving its structural dependents. I therefore argue that the two retrieval operations rely on overlapping pools of resources.by Evelina G. Fedorenko.Ph.D.