As a developmental psychologist, my main areas of research are language development, language disorders, and early childhood development. My specific interests include individual differences in typically-developing and late-talking children. I have worked extensively with the MacArthur-Bates Communicative Development Inventories (CDIs), developing the CDI Scoring program and serving on the CDI Advisory Board. Recent studies explored the causes and consequences of early language processing efficiency in typically-developing children, late talkers, and children born preterm. My current studies examine links between children's language processing skill, early learning environments, and individual differences in language development in monolingual and bilingual learners from diverse backgrounds. In addition to conducting studies that have a basic science focus, I am also Director of Program Evaluation for the Habla Conmigo project, overseeing the evaluation of parenting intervention programs designed to facilitate caregiver engagement in Latina mothers and their young children.
Social Science Research Scholar, Psychology
Director of Curriculum and Evaluation, Habla Conmigo Academy (2015 - Present)
Research Scientist, Department of Psychology, Stanford University (2005 - Present)
Associate Professor, School of Behavioral and Brain Sciences, University of Texas at Dallas (1996 - 2004)
Assistant Professor, Department of Psychology, University of Wisconsin, Madison (1991 - 1996)
Honors & Awards
Endowed Scholar, Callier Center for Communication Disorders, UT Dallas (2001-2003)
Boards, Advisory Committees, Professional Organizations
Member, MacArthur-Bates Communicative Development Inventories Advisory Board (2000 - Present)
Consultant, Mathematica Inc. (2015 - Present)
Post-doctoral Fellow, McDonnell-Pew Foundation for Cognitive Neuroscience, Center for Research in Language, University of California, San Diego, Cognitive Science (1991)
Ph.D., University of California, Berkeley, Developmental Psychology (1989)
MA, University of California, Berkeley, Developmental Psychology (1984)
BA, University of California, Los Angeles, Psychology and Linguistics (1980)
White matter properties associated with pre-reading skills in 6-year-old children born preterm and at term.
Developmental medicine and child neurology
AIM: To assess associations between white matter properties and pre-reading skills (phonological awareness and receptive and expressive language) in children born preterm and at term at the onset of reading acquisition.METHOD: Six-year-old children born preterm (n=36; gestational age 22-32wks) and at term (n=43) underwent diffusion magnetic resonance imaging and behavioural assessments. Tracts were selected a priori based on findings from a study of 6-year-old children born at term: the left-hemisphere arcuate fasciculus and superior longitudinal fasciculus, and right-hemisphere uncinate fasciculus. Using linear regression, we assessed associations between fractional anisotropy of tracts and phonological awareness and receptive and expressive language scores. We investigated whether associations were moderated by prematurity.RESULTS: Fractional anisotropy of the left-hemisphere arcuate fasciculus contributed unique variance to phonological awareness across birth groups. The association between fractional anisotropy of the right-hemisphere uncinate fasciculus and receptive and expressive language was significantly moderated by prematurity.INTERPRETATION: A left-hemisphere tract was associated with phonological awareness in both birth groups. A right-hemisphere tract was associated with language only in the term group, suggesting that expressive and receptive language is mediated by different white matter pathways in 6-year-old children born preterm. These findings provide novel insights into similarities and differences of the neurobiology of pre-reading skills between children born preterm and at term at reading onset.WHAT THIS PAPER ADDS: White matter properties and pre-reading abilities were associated in children born preterm at the onset of reading. The neurobiology of phonological awareness was similar in children born preterm versus children born at term at 6 years. The neurobiology of language was different in children born preterm versus children born at term at 6 years.
View details for PubMedID 29722009
Nonword Repetition and Language Outcomes in Young Children Born Preterm
JOURNAL OF SPEECH LANGUAGE AND HEARING RESEARCH
2018; 61 (5): 1203–15
The aims of this study were to examine phonological short-term memory in children born preterm (PT) and to explore relations between this neuropsychological process and later language skills.Children born PT (n = 74) and full term (FT; n = 60) participated in a nonword repetition (NWR) task at 36 months old. Standardized measures of language skills were administered at 36 and 54 months old. Group differences in NWR task completion and NWR scores were analyzed. Hierarchical multiple regression analyses examined the extent to which NWR ability predicted later performance on language measures.More children born PT than FT did not complete the NWR task. Among children who completed the task, the performance of children born PT and FT was not statistically different. NWR scores at 36 months old accounted for significant unique variance in language scores at 54 months old in both groups. Birth group did not moderate the relation between NWR and later language performance.These findings suggest that phonological short-term memory is an important skill underlying language development in both children born PT and FT. These findings have relevance to clinical practice in assessing children born PT.
View details for PubMedID 29800357
Real-time lexical comprehension in young children learning American Sign Language.
When children interpret spoken language in real time, linguistic information drives rapid shifts in visual attention to objects in the visual world. This language-vision interaction can provide insights into children's developing efficiency in language comprehension. But how does language influence visual attention when the linguistic signal and the visual world are both processed via the visual channel? Here, we measured eye movements during real-time comprehension of a visual-manual language, American Sign Language (ASL), by 29 native ASL-learning children (16-53 mos, 16 deaf, 13 hearing) and 16 fluent deaf adult signers. All signers showed evidence of rapid, incremental language comprehension, tending to initiate an eye movement before sign offset. Deaf and hearing ASL-learners showed similar gaze patterns, suggesting that the in-the-moment dynamics of eye movements during ASL processing are shaped by the constraints of processing a visual language in real time and not by differential access to auditory information in day-to-day life. Finally, variation in children's ASL processing was positively correlated with age and vocabulary size. Thus, despite competition for attention within a single modality, the timing and accuracy of visual fixations during ASL comprehension reflect information processing skills that are important for language acquisition regardless of language modality.
View details for PubMedID 29659103
Speed of Language Comprehension at 18 Months Old Predicts School-Relevant Outcomes at 54 Months Old in Children Born Preterm
JOURNAL OF DEVELOPMENTAL AND BEHAVIORAL PEDIATRICS
2018; 39 (3): 246–53
Identifying which preterm (PT) children are at increased risk of language and learning differences increases opportunities for participation in interventions that improve outcomes. Speed in spoken language comprehension at early stages of language development requires information processing skills that may form the foundation for later language and school-relevant skills. In children born full-term, speed of comprehending words in an eye-tracking task at 2 years old predicted language and nonverbal cognition at 8 years old. Here, we explore the extent to which speed of language comprehension at 1.5 years old predicts both verbal and nonverbal outcomes at 4.5 years old in children born PT.Participants were children born PT (n = 47; ≤32 weeks gestation). Children were tested in the "looking-while-listening" task at 18 months old, adjusted for prematurity, to generate a measure of speed of language comprehension. Parent report and direct assessments of language were also administered. Children were later retested on a test battery of school-relevant skills at 4.5 years old.Speed of language comprehension at 18 months old predicted significant unique variance (12%-31%) in receptive vocabulary, global language abilities, and nonverbal intelligence quotient (IQ) at 4.5 years, controlling for socioeconomic status, gestational age, and medical complications of PT birth. Speed of language comprehension remained uniquely predictive (5%-12%) when also controlling for children's language skills at 18 months old.Individual differences in speed of spoken language comprehension may serve as a marker for neuropsychological processes that are critical for the development of school-relevant linguistic skills and nonverbal IQ in children born PT.
View details for PubMedID 29309294
View details for PubMedCentralID PMC5866178
Validity of caregiver-report measures of language skill for Wolof-learning infants and toddlers living in rural African villages.
Journal of child language
Valid indigenous language assessments are needed to further our understanding of how children learn language around the world. We assessed the psychometric properties and performance of two caregiver-report measures of Wolof language skill (language milestones achieved and vocabulary knowledge) for 500 children (ages 0;4 to 2;6) living in rural Senegal. Item response models (IRM) evaluated instrument- and item-level performance and differential function by gender. Both caregiver-report measures had good psychometric properties and displayed expected age and socioeconomic effects. Modest concurrent validity was found by comparing the caregiver-report scores to transcribed child language samples from a naturalistic play session. The caregiver-report method offers a valid alternative to more costly tools, such as direct behavioral assessments or language sampling, for measuring early language development in non-literate, rural African communities. Recommendations are made to further improve the performance of caregiver-report measures of child language skill in these settings.
View details for PubMedID 29519264
Quality of caregiver-child play interactions with toddlers born preterm and full term: Antecedents and language outcome
EARLY HUMAN DEVELOPMENT
2017; 115: 110–17
Preterm birth may leave long-term effects on the interactions between caregivers and children. Language skills are sensitive to the quality of caregiver-child interactions.Compare the quality of caregiver-child play interactions in toddlers born preterm (PT) and full term (FT) at age 22months (corrected for degree of prematurity) and evaluate the degree of association between caregiver-child interactions, antecedent demographic and language factors, and subsequent language skill.A longitudinal descriptive cohort study.39 PT and 39 FT toddlers individually matched on sex and socioeconomic status (SES).The outcome measures were dimensions of caregiver-child interactions, rated from a videotaped play session at age 22months in relation to receptive language assessments at ages 18 and 36months.Caregiver intrusiveness was greater in the PT than FT group. A composite score of child interactional behaviors was associated with a composite score of caregiver interactional behaviors. The caregiver composite measure was associated with later receptive vocabulary at 36months. PT-FT group membership did not moderate the association between caregiver interactional behavior and later receptive vocabulary.The quality of caregiver interactional behavior had similar associations with concurrent child interactional behavior and subsequent language outcome in the PT and FT groups. Greater caregiver sensitivity/responsiveness, verbal elaboration, and less intrusiveness support receptive language development in typically developing toddlers and toddlers at risk for language difficulty.
View details for PubMedID 29111418
View details for PubMedCentralID PMC5689464
Wordbank: an open repository for developmental vocabulary data
JOURNAL OF CHILD LANGUAGE
2017; 44 (3): 677-694
The MacArthur-Bates Communicative Development Inventories (CDIs) are a widely used family of parent-report instruments for easy and inexpensive data-gathering about early language acquisition. CDI data have been used to explore a variety of theoretically important topics, but, with few exceptions, researchers have had to rely on data collected in their own lab. In this paper, we remedy this issue by presenting Wordbank, a structured database of CDI data combined with a browsable web interface. Wordbank archives CDI data across languages and labs, providing a resource for researchers interested in early language, as well as a platform for novel analyses. The site allows interactive exploration of patterns of vocabulary growth at the level of both individual children and particular words. We also introduce wordbankr, a software package for connecting to the database directly. Together, these tools extend the abilities of students and researchers to explore quantitative trends in vocabulary development.
View details for DOI 10.1017/S0305000916000209
View details for Web of Science ID 000399955900008
Caregiver Talk and Medical Risk as Predictors of Language Outcomes in Full Term and Preterm Toddlers.
This study examined associations between caregiver talk and language skills in full term (FT) and preterm (PT) children (n = 97). All-day recordings of caregiver-child interactions revealed striking similarities in amount of caregiver talk heard by FT and PT children. Children who heard more caregiver talk at 16 months demonstrated better knowledge- and processing-based language skills at 18 months. The unique contributions of caregiver talk were tempered by medical risk in PT children, especially for processing speed. However, there was no evidence that birth status or medical risk moderated the effects of caregiver talk. These findings highlight the role of caregiver talk in shaping language outcomes in FT and PT children and offer insights into links between neurodevelopmental risk and caregiver-child engagement.
View details for DOI 10.1111/cdev.12818
View details for PubMedID 28452393
- Sensitivity to morphosyntactic information in three-year-old children with typical language development: A feasibility study Journal of Speech, Language and Hearing Research 2017; 60: 668-674
Using Eye Movements to Assess Language Comprehension in Toddlers Born Preterm and Full Term.
journal of pediatrics
To assess language skills in children born preterm and full term by the use of a standardized language test and eye-tracking methods.Children born ≤32 weeks' gestation (n = 44) were matched on sex and socioeconomic status to children born full term (n = 44) and studied longitudinally. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) were administered at 18 months (corrected for prematurity as applicable). The Looking-While-Listening Task (LWL) simultaneously presents 2 pictures and an auditory stimulus that directs the child's attention to one image. The pattern of eye movements reflects visual processing and the efficiency of language comprehension. Children born preterm were evaluated on LWL 3 times between 18 and 24 months. Children born full term were evaluated at ages corresponding to chronological and corrected ages of their preterm match. Results were compared between groups for the BSID-III and 2 LWL measures: accuracy (proportion of time looking at target) and reaction time (latency to shift gaze from distracter to target).Children born preterm had lower BSID-III scores than children born full term. Children born preterm had poorer performance than children born full term on LWL measures for chronological age but similar performance for corrected age. Accuracy and reaction time at 18 months' corrected age displaced preterm-full term group membership as significant predictors of BSID-III scores.Performance and rate of change on language comprehension measures were similar in children born preterm and full term compared at corrected age. Individual variation in language comprehension efficiency was a robust predictor of scores on a standardized language assessment in both groups.
View details for DOI 10.1016/j.jpeds.2016.10.004
View details for PubMedID 27816220
Caregiver talk to young Spanish-English bilinguals: comparing direct observation and parent-report measures of dual-language exposure.
In research on language development by bilingual children, the early language environment is commonly characterized in terms of the relative amount of exposure a child gets to each language based on parent report. Little is known about how absolute measures of child-directed speech in two languages relate to language growth. In this study of 3-year-old Spanish-English bilinguals (n = 18), traditional parent-report estimates of exposure were compared to measures of the number of Spanish and English words children heard during naturalistic audio recordings. While the two estimates were moderately correlated, observed numbers of child-directed words were more consistently predictive of children's processing speed and standardized test performance, even when controlling for reported proportion of exposure. These findings highlight the importance of caregiver engagement in bilingual children's language outcomes in both of the languages they are learning.
View details for DOI 10.1111/desc.12425
View details for PubMedID 27197746
View details for PubMedCentralID PMC5116283
Early language processing efficiency predicts later receptive vocabulary outcomes in children born preterm.
2016; 22 (6): 649-665
As rates of prematurity continue to rise, identifying which preterm children are at increased risk for learning disabilities is a public health imperative. Identifying continuities between early and later skills in this vulnerable population can also illuminate fundamental neuropsychological processes that support learning in all children. At 18 months adjusted age, we used socioeconomic status (SES), medical variables, parent-reported vocabulary, scores on the Bayley Scales of Infant and Toddler Development (third edition) language composite, and children's lexical processing speed in the looking-while-listening (LWL) task as predictor variables in a sample of 30 preterm children. Receptive vocabulary as measured by the Peabody Picture Vocabulary Test (fourth edition) at 36 months was the outcome. Receptive vocabulary was correlated with SES, but uncorrelated with degree of prematurity or a composite of medical risk. Importantly, lexical processing speed was the strongest predictor of receptive vocabulary (r = -.81), accounting for 30% unique variance. Individual differences in lexical processing efficiency may be able to serve as a marker for information processing skills that are critical for language learning.
View details for DOI 10.1080/09297049.2015.1038987
View details for PubMedID 26031342
- Relative language exposure, processing efficiency and vocabulary in Spanish- English bilingual toddlers* BILINGUALISM-LANGUAGE AND COGNITION 2014; 17 (1): 189-202
- Short-form versions of the Spanish MacArthur-Bates Communicative Development Inventories APPLIED PSYCHOLINGUISTICS 2013; 34 (4): 837–68
SES differences in language processing skill and vocabulary are evident at 18months
2013; 16 (2): 234-248
This research revealed both similarities and striking differences in early language proficiency among infants from a broad range of advantaged and disadvantaged families. English-learning infants (n = 48) were followed longitudinally from 18 to 24 months, using real-time measures of spoken language processing. The first goal was to track developmental changes in processing efficiency in relation to vocabulary learning in this diverse sample. The second goal was to examine differences in these crucial aspects of early language development in relation to family socioeconomic status (SES). The most important findings were that significant disparities in vocabulary and language processing efficiency were already evident at 18 months between infants from higher- and lower-SES families, and by 24 months there was a 6-month gap between SES groups in processing skills critical to language development.
View details for DOI 10.1111/desc.12019
View details for Web of Science ID 000315384700008
View details for PubMedID 23432833
View details for PubMedCentralID PMC3582035
Individual Differences in Lexical Processing at 18 Months Predict Vocabulary Growth in Typically Developing and Late-Talking Toddlers
2012; 83 (1): 203-222
Using online measures of familiar word recognition in the looking-while-listening procedure, this prospective longitudinal study revealed robust links between processing efficiency and vocabulary growth from 18 to 30 months in children classified as typically developing (n = 46) and as "late talkers" (n = 36) at 18 months. Those late talkers who were more efficient in word recognition at 18 months were also more likely to "bloom," showing more accelerated vocabulary growth over the following year, compared with late talkers less efficient in early speech processing. Such findings support the emerging view that early differences in processing efficiency evident in infancy have cascading consequences for later learning and may be continuous with individual differences in language proficiency observed in older children and adults.
View details for DOI 10.1111/j.1467-8624.2011.01692.x
View details for Web of Science ID 000299465000015
View details for PubMedID 22172209
View details for PubMedCentralID PMC3266972
How vocabulary size in two languages relates to efficiency in spoken word recognition by young Spanish-English bilinguals
JOURNAL OF CHILD LANGUAGE
2010; 37 (4): 817-840
Research using online comprehension measures with monolingual children shows that speed and accuracy of spoken word recognition are correlated with lexical development. Here we examined speech processing efficiency in relation to vocabulary development in bilingual children learning both Spanish and English (n=26 ; 2 ; 6). Between-language associations were weak: vocabulary size in Spanish was uncorrelated with vocabulary in English, and children's facility in online comprehension in Spanish was unrelated to their facility in English. Instead, efficiency of online processing in one language was significantly related to vocabulary size in that language, after controlling for processing speed and vocabulary size in the other language. These links between efficiency of lexical access and vocabulary knowledge in bilinguals parallel those previously reported for Spanish and English monolinguals, suggesting that children's ability to abstract information from the input in building a working lexicon relates fundamentally to mechanisms underlying the construction of language.
View details for DOI 10.1017/S0305000909990055
View details for Web of Science ID 000281565200003
View details for PubMedID 19726000
View details for PubMedCentralID PMC2910833
Does input influence uptake? Links between maternal talk, processing speed and vocabulary size in Spanish-learning children
2008; 11 (6): F31-F39
It is well established that variation in caregivers' speech is associated with language outcomes, yet little is known about the learning principles that mediate these effects. This longitudinal study (n = 27) explores whether Spanish-learning children's early experiences with language predict efficiency in real-time comprehension and vocabulary learning. Measures of mothers' speech at 18 months were examined in relation to children's speech processing efficiency and reported vocabulary at 18 and 24 months. Children of mothers who provided more input at 18 months knew more words and were faster in word recognition at 24 months. Moreover, multiple regression analyses indicated that the influences of caregiver speech on speed of word recognition and vocabulary were largely overlapping. This study provides the first evidence that input shapes children's lexical processing efficiency and that vocabulary growth and increasing facility in spoken word comprehension work together to support the uptake of the information that rich input affords the young language learner.
View details for DOI 10.1111/j.1467-7687.2008.00768.x
View details for Web of Science ID 000260050100002
View details for PubMedID 19046145
View details for PubMedCentralID PMC2898277
Baby's first 10 words
2008; 44 (4): 929–38
Although there has been much debate over the content of children's first words, few large sample studies address this question for children at the very earliest stages of word learning. The authors report data from comparable samples of 265 English-, 336 Putonghua- (Mandarin), and 369 Cantonese-speaking 8- to 16-month-old infants whose caregivers completed MacArthur-Bates Communicative Development Inventories and reported them to produce between 1 and 10 words. Analyses of individual words indicated striking commonalities in the first words that children learn. However, substantive cross-linguistic differences appeared in the relative prevalence of common nouns, people terms, and verbs as well as in the probability that children produced even one of these word types when they had a total of 1-3, 4-6, or 7-10 words in their vocabularies. These data document cross-linguistic differences in the types of words produced even at the earliest stages of vocabulary learning and underscore the importance of parental input and cross-linguistic/cross-cultural variations in children's early word-learning.
View details for DOI 10.1037/0012-1618.104.22.1689
View details for Web of Science ID 000257736300004
View details for PubMedID 18605825
Speed of word recognition and vocabulary knowledge in infancy predict cognitive and language outcomes in later childhood
2008; 11 (3): F9-F16
The nature of predictive relations between early language and later cognitive function is a fundamental question in research on human cognition. In a longitudinal study assessing speed of language processing in infancy, Fernald, Perfors and Marchman (2006) found that reaction time at 25 months was strongly related to lexical and grammatical development over the second year. In this follow-up study, children originally tested as infants were assessed at 8 years on standardized tests of language, cognition, and working memory. Speed of spoken word recognition and vocabulary size at 25 months each accounted for unique variance in linguistic and cognitive skills at 8 years, effects that were attributable to strong relations between both infancy measures and working memory. These findings suggest that processing speed and early language skills are fundamental to intellectual functioning, and that language development is guided by learning and representational principles shared across cognitive and linguistic domains.
View details for DOI 10.1111/j.1467-7687.2008.00671.x
View details for Web of Science ID 000255644100001
View details for PubMedID 18466367
View details for PubMedCentralID PMC2905590
Spoken word recognition by Latino children learning Spanish as their first language
JOURNAL OF CHILD LANGUAGE
2007; 34 (2): 227-249
Research on the development of efficiency in spoken language understanding has focused largely on middle-class children learning English. Here we extend this research to Spanish-learning children (n=49; M=2;0; range= 1 ;3-3; 1) living in the USA in Latino families from primarily low socioeconomic backgrounds. Children looked at pictures of familiar objects while listening to speech naming one of the objects. Analyses of eye movements revealed developmental increases in the efficiency of speech processing. Older children and children with larger vocabularies were more efficient at processing spoken language as it unfolds in real time, as previously documented with English learners. Children whose mothers had less education tended to be slower and less accurate than children of comparable age and vocabulary size whose mothers had more schooling, consistent with previous findings of slower rates of language learning in children from disadvantaged backgrounds. These results add to the cross-linguistic literature on the development of spoken word recognition and to the study of the impact of socioeconomic status (SES) factors on early language development.
View details for DOI 10.1017/S0305000906007896
View details for Web of Science ID 000246669900002
View details for PubMedID 17542157
View details for PubMedCentralID PMC2898269
Grammar and the lexicon: Developmental ordering in language acquisition
2007; 78 (1): 190-212
Recent accounts of language acquisition propose that the knowledge structures that comprise language develop within a single, unified system that shares computational resources and representations. One implication of this approach is that developmental relations within the system become central to theorizing about language acquisition. Previous work suggested that lexical development preceded grammatical development, a developmental ordering with strong theoretical implications. One purpose of the current article is to test this developmental ordering hypothesis. Results showed that children (aged 16-30 months) developed lexicon and grammar synchronously. The second purpose is to demonstrate a recently developed method for testing developmental ordering, the nonlinear-mapping approach, and show how the method can be extended to capitalize on multiply determined developmental systems, such as language.
View details for Web of Science ID 000244517400011
View details for PubMedID 17328700
Picking up speed in understanding: Speech processing efficiency and vocabulary growth across the 2nd year
2006; 42 (1): 98-116
To explore how online speech processing efficiency relates to vocabulary growth in the 2nd year, the authors longitudinally observed 59 English-learning children at 15, 18, 21, and 25 months as they looked at pictures while listening to speech naming one of the pictures. The time course of eye movements in response to speech revealed significant increases in the efficiency of comprehension over this period. Further, speed and accuracy in spoken word recognition at 25 months were correlated with measures of lexical and grammatical development from 12 to 25 months. Analyses of growth curves showed that children who were faster and more accurate in online comprehension at 25 months were those who showed faster and more accelerated growth in expressive vocabulary across the 2nd year.
View details for DOI 10.1037/0012-1622.214.171.124
View details for Web of Science ID 000234844100008
View details for PubMedID 16420121
View details for PubMedCentralID PMC3214591
The language-specific nature of grammatical development: evidence from bilingual language learners
WILEY-BLACKWELL. 2004: 212–24
The fact that early lexical and grammatical acquisition are strongly correlated has been cited as evidence against the view that the language faculty is composed of dissociable and autonomous modules (Bates & Goodman, 1997). However, previous studies have not yet eliminated the possibility that lexical-grammar associations may be attributable to language-general individual differences (e.g. children who are good at learning words are good at learning grammar). Parent report assessments of toddlers who are simultaneously learning English and Spanish (n = 113) allow an examination of the specificity of lexical-grammar relationships while holding child factors constant. Within-language vocabulary-grammar associations were stronger than cross-language relationships, even after controlling for age, proportion of language exposure, general language skill and reporter bias. Similar patterns were found based on naturalistic language samples (n = 22), ruling out a methodological artifact. These results are consistent with the view that grammar learning is specifically tied to lexical progress in a given language and provide further support for strong lexical-grammatical continuity early in acquisition.
View details for DOI 10.1111/j.1467-7687.2004.00340.x
View details for Web of Science ID 000220472500013
View details for PubMedID 15320381
- Concurrent validity of caregiver/parent report measures of language for children who are learning both English and Spanish Journal of Speech, Language and Hearing Research 2002; 45: 983-997
- Picture naming by children with hearing loss: II. Effect of phonologically-related auditory distractors Journal of the American Academy of Audiology 2002; 13: 478-492
- Picture naming by children with hearing loss: I. Effect of semantically-related auditory distractors Journal of the America Academy of Audiology 2002; 13: 463-477
Morphological productivity in children with normal language and SLI: A study of the English past tense
JOURNAL OF SPEECH LANGUAGE AND HEARING RESEARCH
1999; 42 (1): 206–19
Children with specific language impairment (SLI) are known to display persistent difficulties with inflectional morphology--in particular, the overuse of unmarked grammatical forms (i.e., zero-marking). Yet, several recent studies have shown that English-speaking children with SLI, like their normal language peers (NL), demonstrate a considerable degree of productive language abilities (e.g., Bishop, 1994; Loeb & Leonard, 1991; Oetting & Horohov, 1997). In this study, we explore productivity in the English past tense in school-age children with SLI (N= 31) and NL (N = 31) who were equivalent as a group in chronological and mental age. Although children in both groups produced a range of error types, the children with SLI produced significantly more errors, with a greater proportion resulting from zero-marking (e.g., go) than suffixation (e.g., goed). Item analyses indicated that suffixations and zero-markings were predicted by item frequency, phonological features of stems, and similarity relationships across items (i.e., neighborhood structure) in both groups, yet children with SLI were more sensitive to item phonology than their NL peers. Results are interpreted in light of the predictions of dual- versus single-mechanism models of morphological productivity. Implications for accounts of SLI are discussed.
View details for DOI 10.1044/jslhr.4201.206
View details for Web of Science ID 000078352700016
View details for PubMedID 10025555
- Idiom comprehension in children and adults with unilateral brain damage DEVELOPMENTAL NEUROPSYCHOLOGY 1999; 15 (3): 327–49
Narrative discourse in children with early focal brain injury
BRAIN AND LANGUAGE
1998; 61 (3): 335–75
Children with early brain damage, unlike adult stroke victims, often go on to develop nearly normal language. However, the route and extent of their linguistic development are still unclear, as is the relationship between lesion site and patterns of delay and recovery. Here we address these questions by examining narratives from children with early brain damage. Thirty children (ages 3:7-10:10) with pre- or perinatal unilateral focal brain damage and their matched controls participated in a storytelling task. Analyses focused on linguistic proficiency and narrative competence. Overall, children with brain damage scored significantly lower than their age-matched controls on both linguistic (morphological and syntactic) indices and those targeting broader narrative qualities. Rather than indicating that children with brain damage fully catch up, these data suggest that deficits in linguistic abilities reassert themselves as children face new linguistic challenges. Interestingly, after age 5, site of lesion does not appear to be a significant factor and the delays we have witnessed do not map onto the lesion profiles observed in adults with analogous brain injuries.
View details for DOI 10.1006/brln.1997.1882
View details for Web of Science ID 000073366800003
View details for PubMedID 9570869
- Overregularization in English plural and past tense inflectional morphology: a response to Marcus (1995) Journal of Child Language 1997; 24: 767-779
- Children's productivity in the English past tense: The role of frequency, phonology, and neighborhood structure Cognitive Science 1997; 21: 283-304
- Learning from a connectionist model of the acquisition of the English past tense. Cognition 1996; 61: 299-308
- PRODUCTION OF COMPLEX SYNTAX IN NORMAL AGING AND ALZHEIMERS-DISEASE LANGUAGE AND COGNITIVE PROCESSES 1995; 10 (5): 487–539
- Developmental and stylistic variation in the composition of early vocabulary. Journal of Child Language 1994; 21: 85-124
- Continuity in lexical and morphological development: A test of the critical mass hypothesis Journal of Child Language 1994; 21: 339-366
CONSTRAINTS ON PLASTICITY IN A CONNECTIONIST MODEL OF THE ENGLISH PAST TENSE
JOURNAL OF COGNITIVE NEUROSCIENCE
1993; 5 (2): 215–34
Abstract This paper investigates constraints on dissociation and plasticity in a connectionist model undergoing random "lesions" both prior to and during training. When networks were trained only on phonological encodings of stem-suhed pairs similar to English regular verbs (e.g., walk walked), long-term deficits (i.e., "critical period" effects) were not observed, yet there were substantive short-term effects of injury. When training vocabulary reflected the English-like competition between regular (suffixed) and irregular verbs (e.g., go went, hit hit), the acquisition of regular verbs became increasingly susceptible to injury, while the irregulars were learned quickly and were relatively impervious to damage. Patterns of generalization to novel forms conflicts with the assumption that this behavioral dissociation is indicative of selective impairment of the learning and generalization of the past tense rule, while the associative lexical-based mechanism is left intact. Instead, we propose a view of network performance in which the regular-irregular dissociation derives from a general reduction in the ability to find a single-mechanism solution when resolving the competition between two classes of mappings. In light of other models in which "regular" and "irregular" forms compete (e.g., Patterson, Seidenberg, & McClelland, 1989), as well as patterns of performance in normal and disordered English speakers (e.g., Pinker, 1991), two general implications are discussed: (1) critical period effects need not derive from endog-enously determined maturational change, but instead may in part result from learning history in relation to characteristics of the language to be learned (i.e., entrenchment), and (2) selective dissociations can result from general damage in systems that are not modularized in terms of rule-based vs. associative mechanisms.
View details for DOI 10.1162/jocn.19126.96.36.199
View details for Web of Science ID A1993KX01100007
View details for PubMedID 23972155
- From rote learning to system building: Acquiring verb morphology in children and connectionist nets. Cognition 1993; 48: 21-69
- U-shaped learning and frequency effects in a multi-layered perceptron: Implications for child language acquisition Cognition 1991; 38: 43-102