Peter W. Jusczyk - US grants

A series of experiments is proposed for investigating the nature of the basic capacities underlying speech perception in infants and the subsequent development of these capacities in the process of acquiring a native language. Data concerning the infant's discrimination and categorization of speech during the first year of life will be collected using various sucking, visual preference and operant headturning procedures. The information gained from these investigations with infants will provide not only an index of the nature of the basic capacities underlying speech perception, but also an indication of the way these capacities are affected during the infant's first attempts to acquire the sound structure of the language spoken in his or her native environment. Research with older children and adults using categorization measures serves to delineate further the way in which basic speech perception capacities develop as a result of acquiring and using a particular language. Special attention is given to the way in which the organization governing the phonological (i.e. sound) structure of the language affects speech perception. The proposed research, then, aims both to identify the basic capacities underlying speech perception and to define the set of relevant experiences which shape the way in which adults process speech signals. This research has practical relevance for those studying communications disorders. Information about the way in which speech perception develops provides a baseline for assessing abnormalities in processing speech. Early identification of the development of such abnormalities is essential in formulating effective treatment programs.

DESCRIPTION: (Adapted From The Applicant's Abstract.) A series of experiments is proposed to investigate the basic speech perception capacities of infants and the role that such capacities play in acquiring a native language. The proposed research has several objectives. The first is to gain a fuller understanding of basic processing resources that infants have for perceiving speech in their natural environments. Accordingly, some of the proposed studies will investigate how memory and attentional demands affect infants' perception of speech sounds. Information from these investigations achieving the remaining objectives which relate to understanding the role of speech perception capacities in acquiring various elements of the structural organization of a native language. One such objective is to determine when infants learn about regularly occurring patterns involving segmental and suprasegmental features of native language utterances. This in turn, bears on another aim of the proposed research, which is to determine whether sensitivity to such regularities provide the language learner with clues about the underlying organization of utterances in the language. In particular, are there cues in speech that aid learners in discovering linguistically relevant units and their relations to each other? A related objective is to delineate the role that speech perception capacities play in learning words. Other related studies will focus on the nature of the information that is stored in words. Several different methods will be used in the proposed studies. Two- month- olds will be tested using versions of the high-amplitude-sucking procedure. Infants, ranging from 4.5 to 11 months of age, will be tested with versions of the Headturn Preference Procedure. Both procedures are versatile enough to be used not only to examine perceptual capacities, but also to investigate memory for speech information. Speech perception is an important aspect of normal human communication. The proposed studies are intended to clarify the role of speech perception in language acquisition. Not only does such information provide background about the normal range of capacities during the first year, but it helps to identify critical processes for the successful development of communication skills. Such information has practical relevance to those involved in the formation of treatment programs for communication disorders.

This project is being funded through the Learning and Intelligent Systems (LIS) initiative. It is interdisciplinary research in the knowledge, processing, and learning of language. It proceeds from a framework utilizing results from mathematical statistics, adaptive systems, and formal learning theory which provide a means of treating language as a kind of statistical optimization. Previous work by the principal investigator on the integration of linguistic theory with optimization principles in neural networks has led to this new grammar formalism, optimality theory, which has had considerable impact on many aspects of the study of human language, including learning. Recently developed methods of psychological experimentation now provide reliable data on the process of language learning, even in infants. This research brings together these experimental methods for observing real-time processing and learning of language, computational methods of research on optimization and automatic language processing, and linguistic methods for studying the structure of the representations essential for human language. The investigators bring not only expertise in the contributing disciplines, but also considerable experience in interdisciplinary collaboration. The results of this research will help us to explain the mystery of how humans - and possibly artificial systems - can learn to use and understand languages.

DESCRIPTION (Applicant's Abstract): This is a request for a NIH Senior Scientist Award. A major objective during the tenure of the requested award is to advance research aimed at understanding the role that speech perception capacities play in the acquisition of language. Achievement of this aim requires (1) a careful assessment of the existing research on infant speech perception and language acquisition; (2) a deeper understanding of recent developments and theorizing in relevant areas of linguistics and psycholinguistics; (3) enhancement of skills in computer modeling of developmental change; and (4) more time in the laboratory to develop the appropriate infant testing procedures for examining crucial aspects of language acquisition. Toward the first of these requirements, the applicant has just written a book which focuses on the development of speech perception capacities and their role in language acquisition. The research undertaken to complete the book has helped to set the direction for the proposed studies. Further training in relevant areas of linguistics, and visits to laboratories of investigators at the forefront of language acquisition research, are proposed to meet the second requirement. Enhancement of skills in computer modeling will be accomplished by additional course work and training in the use of these techniques and by visits to relevant laboratories to discuss modeling of developmental change in language acquisition. The increased time available to the applicant by release from teaching and committee duties will facilitate the development of the new testing procedures and help to launch the kinds of longitudinal studies needed to explore the frontiers between speech perception capacities and language acquisition. Increased understanding of the role that speech perception capacities play in acquiring language helps to identify critical processes for the successful development of communication skills. Such information has practical relevance to those involved in the formulation of treatment programs for communication disorders.

This Integrative Graduate Education and Research Training (IGERT) award supports the establishment of a multidisciplinary graduate training program of education and research in a new paradigm of graduate education: Problem-Centered training, delimited not by the boundaries of an academic discipline, but by the demands of solving a problem. Students are trained in a broad range of research methods derived from a diverse set of traditional disciplines. The general problem targeted by this IGERT program is: "How does the brain achieve its function?" The program focuses on one particularly important cognitive function: language. Basic research on language has long-term implications for diagnosis and treatment of language-related neurological and learning disorders, for literacy and language education, and for digital language technologies. The computational framework of cognitive science allows the problem to be formulated more precisely: What are the representational structures, processing algorithms, and learning algorithms underlying our linguistic abilities? How are these representations and algorithms realized in the brain? Studying with internationally recognized leaders at Johns Hopkins, IGERT trainees acquire both theoretical and empirical sophistication through a uniquely multidisciplinary range of research methods: (i) computational and mathematical modeling of language processing and learning, including symbolic methods and neural networks, in a range of linguistic formalisms; (ii) psychological experimentation on adult and infant language processing and learning; (iii) neuroimaging of brain activity during language processing; (iv) grammatical analysis of the language of adults, children, and second-language learners; (v) neuropsychology of language deficits from acquired and developmental neurological damage; and (vi) computational methods of automatic speech and language processing.

IGERT is an NSF-wide program intended to facilitate the establishment of innovative, research-based graduate programs that will train a diverse group of scientists and engineers to be well-prepared to take advantage of a broad spectrum of career options. IGERT provides doctoral institutions with an opportunity to develop new, well-focussed multidisciplinary graduate programs that transcend organizational boundaries and unite faculty from several departments or institutions to establish a highly interactive, collaborative environment for both training and research. In this second year of the program, awards are being made to twenty-one institutions for programs that collectively span all areas of science and engineering supported by NSF. This specific award is supported by funds from the Directorates for Social, Behavioral, and Economic Sciences, for Biological Sciences, for Computer and Information Science and Engineering, and for Education and Human Resources.