Letitia Naigles - US grants

The long-term goal of the research is to discover how the meanings of words are learned by young children; that is, how the child maps the sounds of language onto their meanings. This goal will be addressed by considering two problems the child faces in learning words: the induction and conflation problems. The induction problem exists for the acquisition of nouns and adjectives as well as verbs, and reflects the fact that the world from which the child discovers word meanings is rich and complex; so much so, that observation alone seems insufficient to determine the referent of a word. The conflation problem exists only for verbs, and derives from the fact that the patter of components of verb meaning that are incorporated, or conflated, into the actual verb differs across languages. The proposed studies will examine in detail another source of information for verb learning; namely, the syntactic structures in which verbs appear. Extensive investigations have revealed many regularities between syntax and verb semantics; these studies will explore whether and to what extent children can use these regularities to learn new verbs--a process termed Syntactic Bootstrapping. The primary questions to be addressed include: How deeply within the lexicon can syntax aid verb acquisition? The fact that many verbs can appear in several different syntactic structures in the adult language suggests another question: Do multiple presentations (a variety of structures each presented once as opposed to one structure presented several times) aid in verb learning? And finally, how and when are the regularities between syntax and verb semantics, which feed the process of syntactic bootstrapping, learned? The majority of these questions will be studied using a new language comprehension method, which allows us to investigate in some detail the linguistic knowledge of children as young as twelve months of age.

9731870 Naigles This proposal development visit will allow the principal investigator, Professor Letitia Naigles of Yale University, to travel to LaTrobe University in Victoria, Australia, for two weeks to discuss a cooperative research project with Edith Bavin of the LaTrobe University School of Psychological Science. The subject of the study is the relationship between early syntactic and vocabulary development. Previous studies have approached the problem from the point of language production, with mixed results. The new method they will apply, comprehension method of preferential looking, to assess young children's grammatical knowledge. The project will establish the new method in Australia leading to more accurate assessments of linguistic knowledge in children acquiring English around the world. The Australian investigator, Edith Bavin, is internationally known and respected for her linguistic research. She has recently turned her attention to the acquisition of knowledge, particularly native languages of Australia. Thus this collaboration also holds the possibility of increased insight on the main problem based on knowledge of acquisition of languages other than English. This is a new partnership which promises to lead to increased cooperation in linguistics between the United States and Australia.

[unreadable] DESCRIPTION (provided by applicant): Language development in typical children follows specific developmental sequences and demonstrates inherent biases at certain stages. It is not known to what degree language development in children with autism follows the same developmental rules or achieves language competence via different routes. The proposed study investigates two interrelated questions: First, is the process of language acquisition in autism similar to that of typically developing children? And second, what do language comprehension measures reveal about the process and products of language acquisition in children with autism? The proposed longitudinal study will use a language comprehension paradigm (Intermodal Preferential Looking, IPL) that has revealed important information about language in typical children 15 and 36 months of age but has not been used lo study autism. It combines the ability to display dynamic events with the necessity of only minimal response (visual fixation) and may reveal strengths and weaknesses not shown on standardized testing. Participants will be 18-36 months old, recently diagnosed with autism/PDD and about to begin a home Applied Behavior Analysis (ABA) program. A baseline assessment before treatment will be followed by assessments at 4-6 month intervals for 2 years, plus a final assessment at age 5-7 years. IPL will be used o examine multiple aspects of language such as word order in sentences and verb learning; the children will also be videotaped during naturalistic interaction with their mothers to provide information about spontaneous language production. Standardized assessments of the children's linguistic, nonverbal, and social functioning will also be obtained. Analyses will focus on (a) the degree to which comprehension exceeds production, (b) the degree to which preferential looking reveals more language ability than is demonstrated with traditional response methods (point, touch) and tests, (c) whether language development in ABA-created children with autism follows typical progressions and inherent biases, and (d) how early patterns of language development might predict ASD children's language abilities at ages 5-7. Results have the potential to provide useful new information to aid treatment by pinpointing subtle deficits and strengths in language, as well as to illuminate possibly different developmental pathways in language acquisition. [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): This project seeks to investigate two critical questions in child language acquisition: (1) WHEN do toddlers show evidence of grammatical productivity in comprehension? (2) HOW does this productivity emergence vary, both cross-linguistically (i.e., do children learning some languages demonstrate earlier emergence than children learning other languages?) and within a given language, across grammatical constructions (i.e., do some grammatical constructions yield earlier emergence of productivity than others?)? This project addresses these questions by bringing together two usually-separate strands in language acquisition research. First, this will be one of the first studies of children's early grammatical productivity to take a cross- linguistic approach, focusing on three languages which have been selected to enable multiple types of comparisons. Second, this will be one of the first cross-linguistic studies of early grammatical knowledge to have comprehension at its core, as children's emerging productivity will be assessed via the intermodal preferential looking paradigm (IPL). Children's early grammatical productivity in verb morphology and syntax will be assessed in English, French, and Turkish. These languages vary most obviously in their reliance on word order (English) versus verbal inflections (i.e., clitic pronouns; French) versus nominal inflections (Turkish) for marking argument structure in the basic clause. Four sets of experiments, which investigate the acquisition of language-specific argument structure will be conducted. These ask when children demonstrate productivity with word order (Study 1), verbal morphology relevant to thematic relations (Study 2), noun case markings (Study 3), and structural bootstrapping (Study 4). Comparisons will be made across languages for each experiment and across experiments for each language. This research could reveal when children's language abilities become adult-like in one important way. Its focus on comprehension and its comparison of different languages could reveal how the age of this ability depends on the task (understanding rather than speaking) and the language being learned. This research thus could provide information about language- and task-specific milestones for assessing children with language disorders. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): Language development in typical children follows specific developmental sequences and demonstrates inherent biases at certain stages. It is not known to what degree language development in children with autism follows the same developmental rules or achieves language comprehension via different routes. The proposed study investigates two interrelated questions: First, are the processes of language acquisition and development in autism similar to that of typically developing children? And second, what do language comprehension measures reveal about the processes and products of language acquisition in children with autism? The proposed longitudinal study will use a language comprehension paradigm (Intermodal Preferential Looking, IPL) that has revealed important information about language in typically children between 15 and 36 months of age but has only just begun to be used with autism. It combines the ability to display dynamic events with the necessity of only minimal response (visual fixation) and may reveal strengths and weaknesses not shown on standardized testing. Participants will be 18-42 months old, recently diagnosed with autism/PDD and about to begin an Applied Behavior Analysis (ABA) program. A baseline assessment before treatment will be followed by assessments at 4-month intervals for 2+years, plus a final assessment at 6-8 years. IPL will b used to examine multiple aspects of language such as word order in sentences and biases in word learning; the children will also be videotaped during naturalistic interaction with their mothers to provide information about spontaneous language production. Standardized assessments of the children's linguistic, nonverbal, and social functioning will also be obtained. Analyses will focus on (a) the degree to which comprehension precedes production, (b) the degree to which preferential looking measures reveal more language abilities than are demonstrated with traditional response methods and tests, (c) whether language development in ABA-treated children with autism follows typical progressions and inherent biases, and (d) how early patterns of language development might predict ASD children's language abilities at ages 6-8. PUBLIC HEALTH RELEVANCE: This project has the potential to provide useful new information to aid in developing treatment plans for children with autism. The project may pinpoint subtle deficits and strengths in the language of children with autism, as well as to illuminate possibly different developmental pathways in their language acquisition, both of which may guide new treatment protocols, especially early in development. [unreadable] [unreadable] [unreadable]

Project Summary/Abstract Language use in ASD is extremely heterogeneous, ranging from age-appropriate to nonverbal. The PI has tracked language development in three cohorts of children with ASD (total N = 42) for the past 8-12 years, from initial diagnosis at approximately 2.5 years to follow-up at 5-8 years, with typically developing (TD) controls (total N = 45) language-matched at study onset (the Longitudinal Study of Early Language; LSEL). We demonstrated the utility of fine-grained measures of production and comprehension in characterizing individual variation in both groups. These children are now in middle childhood to adolescence, allowing us to study language use appropriate to this age, its relationship to `individual' early child and parent language measures from the LSEL and `interactive' measures drawn from parent-child conversational dynamics. This project investigates three questions about the language of school age children with ASD or TD: How does variability in children's grammatical, semantic, and pragmatic language usage during school age demonstrate the inter-dependence vs. distinctiveness of these language areas? We hypothesize that composite measures of grammar and semantics collected in the current project will manifest distinctiveness, with little overlap in variability. Composite measures of semantics and pragmatics will manifest stronger inter-dependence. (2) Which individual early child and parent measures predict children's school age language use? We hypothesize that early child measures of grammar, semantics, and social cognition will predict school age measures in the same domains (e.g., early grammatical processing will predict grammatical usage at school age). We also hypothesize that parents who used more diverse words and grammatical constructions during earlier time periods will have children with more advanced categorization and grammatical usage at school age, and that parents who used more decontextualized language and provided more narrative scaffolding during earlier time periods will have children who use more sophisticated narratives at school age. We expect that early parent measures will exert relatively more influence on later language in the TD vs. ASD group. (3) Which early and concurrent measures of interactive conversational behavior will vary by group and predict children's school age language use? We examine the relationships between interactive dynamics during play sessions gathered when the children were preschoolers, and their school age language. We hypothesize that turn-taking and backchanneling will be more prevalent in TD dyadic interactions than in interactions with children with ASD while alignment measures will vary less by group. Moreover, conversational dynamics measures will predict aspects of children's subsequent speech and comprehension levels, as well as their narratives during school age. Finally, conversational dynamics measures will mediate the predictive power of individual measures, possibly in interaction with diagnosis.