Research Cluster on Language
The language group works from strong interest in linguistic theory, coupled with experimental, formal, computational and theoretical research in language acquisition and processing. The research and training carried out by this group is informed by scholarship in linguistics, computational linguistics, psycholinguistics of sentence processing, neurolinguistics, learning theory, and the philosophy of language -- including foundational concerns about semantics and representation. Graduate students from all of the participating programs and departments who are interested in the cognitive science of language take advantage of the breadth and depth of the language group by taking classes and doing research with its members.
A principal focus of theoretical linguistic research is on Optimality Theory, a new approach to grammatical theory developed by Alan Prince (Linguistics, RuCCS) and his collaborators Paul Smolensky (Johns Hopkins U.) and John McCarthy (U. Massachusetts, Amherst). The basic idea of Optimality Theory is that the grammatical calculation of well-formedness is accomplished through optimization with respect to a set of constraints on structure and on input-output disparity, rather than through the serial application of rules subject to filtering constraints. The constraints of Optimality Theory are held to be universal over all human languages, and conflicts between them are adjudicated by strict prioritization or ranking, rather than through any scheme of numerical weighting. Because Optimality Theory presents a grammatical architecture rather than an approach to a particular substantive subdomain, it has consequences for many areas of linguistic and psycholinguistic analysis. Prince's main area of research is phonology, particularly in its prosodic and prosodic-morphological aspects. Jane Grimshaw (Linguistics, RuCCS) has developed Optimality Theory in the context of syntax, focusing on theories of phrase structure and on the representation and acquisition of lexical information. The second focus of theoretical linguistic research is also within a constraint-based framework, but one in which linguistic variation arises from small, parametric changes in constraints across languages. For example, through their research on the syntax of English, Romance and other languages, Mark Baker (Linguistics, RuCCS), Viviane Deprez (Linguistics) and Ken Safir (Linguistics) seek to uncover the universal principles and the range of parametric variation necessary to account for the observed cross-linguistic phenomena. Research within the parametric and optimality-theoretic frameworks delineates strong constraints on the structure and representation of universal linguistic knowledge, enabling informed cross-disciplinary research in the processing and acquisition of language, as well as the cognitive lexicon. The Linguistics Department offers a wide range of graduate courses and seminars in syntax, semantics, morphology and phonology.
Research on human linguistic processing is strengthened by the multidisciplinary approach at RuCCS, in which evidence from many sources is brought to bear to determine the essential cognitive properties of linguistic abilities. The language group seeks to uncover the grammatical, computational, psychological and neural limitations on language comprehension that interact to constrain the architecture of the language processing system. Bruce Tesar (Linguistics, RuCCS) has adapted dynamic programming-based parsing techniques to work with grammatical theories based on Optimality Theory. Tesar’s algorithms simultaneously inform our understanding of language processing and language learning, as the parsing algorithms play an important role in Tesar’s models of language learning. Jerry Fodor (Philosophy, RuCCS) has argued that certain formal properties are necessary for any computational architecture underlying human linguistic processing, providing further constraints on proposed models. Empirical studies provide not only the behavioral data which the group seeks to explain, but also yield crucial evidence about the processing architecture and its limitations, and the cognitive structures underlying this knowledge. Karin Stromswold (Psychology, RuCCS) and Fodor contribute from this perspective by conducting psycholinguistic experiments that investigate the structure of lexical, syntactic, and semantic knowledge. Stromswold further explores the properties of the language processing architecture through the use of functional neuroimaging techniques (PET and MRI). Matthew Stone (Computer Science, RuCCS) conducts research directed toward the ultimate goal of constructing conversational agents, programs that can understand and contribute to spoken dialogue with a human user in ordinary natural language. His research in attacking such problems is guided by a number of general hypotheses about the use, structure and meaning of human language, which help to bridge the perspectives of artificial intelligence and the language sciences. Graduate courses and seminars in language processing are offered by the Computer Science Department (e.g., Natural language processing, taught by Stone), the Psychology Department (e.g., courses in psycholinguistics and neurolinguistics taught by Stromswold), and RuCCS (e.g., courses in psycholinguistics taught by Jerry Fodor and in the past by David Swinney and Jacques Mehler).
Faculty in the Departments of Computer Science, Linguistics, Philosophy, Psychology and at RuCCS conduct formal, computational, theoretical, and empirical research that seeks to elucidate the constraints that enable the successful acquisition of language. Stromswold's empirical and theoretical research on the acquisition of language by normal and impaired children seeks 1) to delineate those aspects of language that are innate from those that must be learned; 2) to investigate the genetic and neural bases of language; and (3) to investigate parametric models of the acquisition and structure of syntactic representations in children and adults. Also working within a parametric framework, Deprez's empirical and theoretical research focuses on the structure and acquisition of Romance languages and English, and Safir's research focuses on the cross-linguistic acquisition of anaphora. Robert Matthews (Philosophy) focuses on formal learning-theoretic models of first language acquisition, especially on models based on parametrized linguistic theories. Tesar’s computational research on language learning investigates the implications of the formal structure of linguistic theory for language learning. Focusing on Optimality Theory, Tesar has developed algorithms for grammar learning that exploit the formal structure of Optimality Theory to effectively contend with problems such as structural ambiguity (“the bootstrapping problem”) and learning restrictive distributions (“the subset problem”). Also working within the Optimality-Theoretic framework, Grimshaw is pursuing work on multiple sublexicons and the problem of apparent optionality. Graduate courses are offered by the Linguistics Department (e.g. Tesar’s course on language acquisition, the Philosophy Department (e.g., a formal learnability seminar offered by Matthews), the Psychology Department (e.g., a language acquisition course by Stromswold), and RuCCS (e.g., seminars by Lila Gleitman and others).
Language and Cognition: The Lexicon
A final focus of research interest in the language group at RuCCS is the connection between the structure of concepts and the structure of the semantic lexicon. These ssues are connected by the assumption that whatever functions as the categories to which stimuli are assigned in perception, and as the constituents of thoughts in cognitive processes, should also serve as the semantic representatives of words in the speaker/hearer's internal representation of language. What psychological theory claims about concepts is thus constrained by what semantic (specifically linguistic and logical) theories say about word meanings; and vice versa. This convergence of concerns provides the possibility for a new integration of theoretical work in linguistics, philosophy and logic with experimental work in psychology. Among those whose work is directly involved with these issues are Fodor (structure of concepts; lexical semantics), Lepore (lexical semantics, theories of vagueness, supervaluation theory), Grimshaw (lexical decomposition and verb structure) and Leslie (conceptual structure in ontogeney and in autism), Schmidt (conceptual structure and planning), Leyton and Feldman (conceptual structure in vision and memory) and McLaughlin (connectionist approaches to conceptual and cognitive architecture). Under Fodor's supervision, a doctoral dissertation (in Philosophy) has just been completed on theories of concepts and their relation to problems of composition, and another (in Psychology) currently underway involves experiments testing linguistic theories about the lexical structure of English verbs. As a further example of the cross-disciplinary nature of these explorations, Grimshaw and Leslie have found remarkable similarities between the skeletal linguistic semantics needed for syntax and the primitive elements underlying early cognition. At a more abstract level, Prince and Feldman have discerned a number of formal connections between language and vision in the optimization of violable constraints, revealing the crucial role of constraint satisfaction in the processing of very different cognitive materials.