Using machine-learning methods to identify early-life predictors of 11-year language outcome

BACKGROUND

Language is foundational for neurodevelopment and quality of life, but an estimated 10% of children have a language disorder at age 5. Many children shift between classifications of typical and low language if assessed at multiple times in the early years, making it difficult to identify which children will have persisting difficulties and benefit most from support. This study aims to identify a parsimonious set of preschool indicators that predict language outcomes in late childhood, using data from the population-based Early Language in Victoria Study (n = 839).

METHODS

Parents completed surveys about their children at ages 8, 12, 24, and 36 months. At 11 years, children were assessed using the Clinical Evaluation of Language Fundamentals 4th Edition (CELF-4). We used random forests to identify which of the 1990 parent-reported questions best predict children's 11-year language outcome (CELF-4 score ≤81 representing low language) and used SuperLearner to estimate the accuracy of the constrained sets of questions.

RESULTS

At 24 months, seven predictors relating to vocabulary, symbolic play, pragmatics and behavior yielded 73% sensitivity (95% CI: 57, 85) and 77% specificity (95% CI: 74, 80) for predicting low language at 11 years. [Corrections made on 5 May 2023, after first online publication: In the preceding sentence 'motor skills' has been corrected to 'behavior' in this version.] At 36 months, 7 predictors relating to morphosyntax, vocabulary, parent-child interactions, and parental stress yielded 75% sensitivity (95% CI: 58, 88) and 85% specificity (95% CI: 81, 87). Measures at 8 and 12 months yielded unsatisfactory accuracy.

CONCLUSIONS

We identified two short sets of questions that predict language outcomes at age 11 with fair accuracy. Future research should seek to replicate results in a separate cohort.

Spoken Expressive Vocabulary in 2-Year-Old Children with Hearing Loss: A Community Study

Through a cross-sectional community study of 2044 children aged 2 years, we (1) examine the impact of hearing loss on early spoken expressive vocabulary outcomes and (2) investigate how early intervention-related factors impact expressive vocabulary outcomes in children with hearing loss predominantly identified through universal newborn hearing screening. We used validated parent/caregiver-reported checklists from two longitudinal cohorts (302 children with unilateral or bilateral hearing loss, 1742 children without hearing loss) representing the same population in Victoria, Australia. The impact of hearing loss and amplification-related factors on vocabulary was estimated using g-computation and multivariable linear regression. Children with versus without hearing loss had poorer expressive vocabulary scores, with mean scores for bilateral loss 0.5 (mild loss) to 0.9 (profound loss) standard deviations lower and for unilateral loss marginally (0.1 to 0.3 standard deviations) lower. For children with hearing loss, early intervention and amplification by 3 months, rather than by 6 months or older, resulted in higher expressive vocabulary scores. Children with hearing loss demonstrated delayed spoken expressive vocabulary despite whole-state systems of early detection and intervention. Our findings align with calls to achieve a 1-2-3 month timeline for early hearing detection and intervention benchmarks for screening, identification, and intervention.

Associations between responsive parental behaviours in infancy and toddlerhood, and language outcomes at age 7 years in a population-based sample

BACKGROUND

A wealth of evidence supports the important role high-quality parent-child interactions play in children's early language acquisition. However, the impact on later language outcomes remains unclear.

AIMS

To examine the associations between responsive parental behaviours across the early years and child language outcomes at age 7 years with families from an Australian longitudinal cohort study (N = 1148, 50% female).

METHODS & PROCEDURES

At child ages 12, 24 and 36 months, parents completed a self-report measure of responsive parental behaviours. Child language was directly assessed at age 7 using the Clinical Evaluation of Language Fundamentals, 4th edition (CELF-4), Australian Standardisation. Linear regression was used to examine associations between responsive parental behaviours from 12 to 36 months (consistently high, inconsistent and consistently low responsive parental behaviours at the three time points) and language scores at age 7 years. Adjusted models were run, including the following potential confounders: child sex; birth weight; birth order; maternal education; socio-economic disadvantage; non-English-speaking background; family history of speech-language problems; mother's vocabulary score; maternal mental health score; and mother's age at birth of child. A final adjusted model was run, including the potential confounder variables as well as adjusting for children's earlier language skills.

OUTCOMES & RESULTS

Linear regression results showed children with parents who rated high on responsive parental behaviours at all three time points had higher mean language scores at age 7 than children whose parents reported low responsive parental behaviours across early childhood. This association attenuated after adjusting for earlier child language skills.

CONCLUSIONS & IMPLICATIONS

Findings support the consistent use of responsive parental behaviours across the very early years of childhood to support long-term language outcomes. Findings also suggest that models of surveillance and support which monitor and assist families at multiple time-points over the early years are likely to be most effective for preventing ongoing language difficulties.

WHAT THIS PAPER ADDS

What is already known on this subject There is extensive evidence consistently demonstrating the important contribution of aspects of parent-child interaction, specifically responsive parental behaviours, to children's language development. What this paper adds to the existing knowledge Understanding the cumulative benefit of responsive parent-child interactions across the very early years may help to inform preventive interventions and service delivery models for supporting young children's language development. This study demonstrates in a large, population-based cohort the contribution of consistency of responsive parental behaviours during infancy and toddlerhood to school-age language outcomes, accounting for other child, family and environmental factors. Capturing regular parent behaviours via self-report during the early years may be a more efficient and less costly method than parent-child interaction observations to monitor the home language-learning environment during routine developmental checks. What are the potential or actual clinical implications of this work? Findings support the need for surveillance of children and families in the early years, ensuring that intervention occurs when families need it most, that is, support is responsive to changing needs and that nuanced advice and support strategies are provided to activate positive developmental cascades. Capturing both parent behaviours and child language may assist clinicians to identify those families who may benefit from parent-child interaction intervention.

Health-related quality of life of caregivers of children with low language: Results from two Australian population-based studies

Purpose: To examine (1) the association between low language (LL) and caregiver's health-related quality of life (HRQoL), (2) whether persistent LL affects caregiver's HRQoL and (3) whether child social-emotional-behavioural (SEB) difficulties attenuates the association between LL and caregiver's HRQoL.Method: Data were from the Early Language in Victoria Study (ELVS) and the Longitudinal Study of Australian Children (LSAC). Caregiver's HRQoL was measured using the EuroQoL-5 dimensions and the Assessment of Quality of Life-8 dimensions. Language ability was determined using the Clinical Evaluation of Language Fundamentals (CELF)-Preschool-2nd or 4th edition (ELVS) and the Peabody Picture Vocabulary Test-3^rd edition or CELF-4 recalling sentences subscale (LSAC). Child SEB difficulties were measured using the Strengths and Difficulties Questionnaire. Multivariable linear regression was used for the analysis.Result: At 11-12 years, an association between LL and reduced caregiver's HRQoL was found in LSAC, but not in ELVS. Persistent LL from 4-11 years seemed to not affect caregivers' HRQoL in either cohort. Child SEB difficulties attenuated the association between caregiver's HRQoL and LL.Conclusion: Both LL and SEB difficulties contributed to reduced caregiver's HRQoL at children age 11-12 years. Interventions supporting children with LL should consider caregiver's well-being in provision of care that meets families' needs.

Developing Preschool Language Surveillance Models - Cumulative and Clustering Patterns of Early Life Factors in the Early Language in Victoria Study Cohort

BACKGROUND

Screening and surveillance of development are integral to ensuring effective early identification and intervention strategies for children with vulnerabilities. However, not all developmental skills have reliable screening processes, such as early language ability.

METHOD

We describe how a set of early life factors used in a large, prospective community cohort from Australia are associated with language abilities across the preschool years, and determine if either an accumulation of risk factors or a clustering of risk factors provide a feasible approach to surveillance of language development in preschool children.

RESULTS

There were 1,208 children with a 7-year language outcome. The accumulation of early life factors increased the likelihood of children having low language skills at 7-years. Over a third of children with typical language skills (36.6%) had ≤ two risks and half of the children with low language (50%) had six or more risks. As the number of factors increases the risk of having low language at 7-years increases, for example, children with six or more risks had 17 times greater risk, compared to those with ≤ two risks. Data collected from 1,910 children at 8- to 12-months were used in the latent class modeling. Four profile classes (or groups) were identified. The largest group was developmentally enabled with a supportive home learning environment (56.2%, n = 1,073). The second group was vulnerable, both developmentally and in their home learning environment (31.2%, n = 596); the third group was socially disadvantaged with a vulnerable home learning environment (7.4%, n = 142); the final group featured maternal mental health problems and vulnerable child socio-emotional adjustment (5.2%, n = 99). Compared to developmentally enabled children, the risk of low language at 7-years was greater for children in the three other groups.

CONCLUSION

The cumulative and cluster risk analyses demonstrate the potential to use developmental surveillance to identify children within the first years of life who are at risk of language difficulties. Importantly, parent-child interaction and the home learning environment emerged as a consistent cluster. We recommend they be adopted as the common focus for early intervention and universal language promotion programs.

Positive Parenting Behaviors: Impact on the Early Vocabulary of Infants/Toddlers With Cochlear Implants

Purpose To extend our knowledge about factors influencing early vocabulary development for infants with cochlear implants (CIs), we investigated the impact of positive parenting behaviors (PPBs) from the Indicator of Parent Child Interaction, used in parent-child interactions during everyday activities. Method Implantation age for the sample recruited from CI clinics in Australia ranged from 6 to 10 months for 22 children and from 11 to 21 months for 11 children. Three observation sessions at three monthly intervals were coded for use of PPBs. Children's productive vocabulary, based on the MacArthur-Bates Communicative Development Inventories parent checklist, was collected approximately 6 and 9 months later. A repeated-measures negative binomial generalized linear mixed-effects model was used to investigate associations between the total PPBs per session, covariates (maternal education, gender, and time since implant), and the number of words produced. In follow-up analyses with the PPBs entered separately, variable selection was used to retain only those deemed informative, based on the Akaike information criterion. Results As early as Session 1, associations between the PPBs and vocabulary were identified. Time since implant had a positive effect. For different sessions, specific PPBs (descriptive language, follows child's lead, and acceptance and warmth) were identified as important contributors. Conclusions Complementing previous findings, valuable information was identified about parenting behaviors that are likely to impact positively the early vocabulary of infants with CIs. Of importance is providing parents with information and training in skills that have the potential to help create optimal contexts for promoting their child's early vocabulary development.

Health-related quality of life of children with low language from early childhood to adolescence: results from an Australian longitudinal population-based study

BACKGROUND

Low language abilities are known to be associated with significant adverse long-term outcomes. However, associations between low language and health-related quality of life (HRQoL) are unclear. We aimed to (a) examine the association between low language and HRQoL from 4 to 13 years and (b) classify the children's trajectories of HRQoL and language and examine the association between language and HRQoL trajectories.

METHODS

Data were from an Australian community-based cohort of children. HRQoL was measured at ages 4-13 years using the parent-reported Pediatric Quality of Life Inventory 4.0. Language was assessed using the Clinical Evaluation of Language Fundamentals (CELF)-Preschool 2nd edition at 4 years and the CELF-4th edition at 5, 7 and 11 years. Multivariable linear regression and mixed effect modelling were used to estimate cross-sectional and longitudinal associations between low language and HRQoL from 4 to 13 years. A joint group-based trajectory model was used to characterize associations between HRQoL and language trajectories over childhood.

RESULTS

Children with low language had substantially lower HRQoL than children with typical language from 4 to 13 years. Higher language scores were associated with better HRQoL, particularly in social and school functioning. Three HRQoL trajectories were identified: stable-high (51% of children), reduced with slow decline (40%) and low with rapid decline (9%). Children with low language were less likely to follow a stable-high HRQoL trajectory (40%) while 26% and 34% followed the reduced with slow decline and low with rapid decline trajectories, respectively.

CONCLUSIONS

Children with low language experienced reduced HRQoL from 4 to 13 years. More than half had declining trajectories in HRQoL highlighting the need to monitor these children over time. Interventions should not only aim to improve children's language ability but also address the wider functional impacts of low language.

Predictors in Infancy for Language and Academic Outcomes at 11 Years

OBJECTIVES

To examine the contribution of early life factors and preschool- and school-aged language abilities to children's 11-year language and academic outcomes.

METHODS

Participants (N = 839) were from a prospective community cohort study of 1910 infants recruited at 8 to 10 months of age. Early life factors included a combination of child (prematurity, birth weight), family (socioeconomic disadvantage, family history of language difficulties), and maternal factors (education, vocabulary, and age). Language (standardized assessment of receptive and expressive skills) and academic (national assessment) outcomes at 11 years were predicted by using a series of multivariable regression models.

RESULTS

Early life factors explained 11% to 12% of variance in language scores at 11 years. The variance explained increased to 47% to 64% when language scores from 2 to 7 years were included. The largest increase in variance explained was with 4-year language scores. The same early life factors explained 13% to 14% of academic scores at 11 years, with increases to 43% to 54% when language scores from 2 to 11 years were included. Early life factors adequately discriminated between children with typical and low language scores but were much better discriminators of children with typical and low academic scores. When earlier language scores were added to models then the area under the curve increased to 0.9 and above.

CONCLUSIONS

Children's language outcomes at 11 years are accurately predicted by their 4-year language ability and their academic outcomes at 11 years are predicted by early family and home environment factors. Children with low language abilities at 11 years consistently performed more poorly on national assessments of literacy and numeracy.

Modelling the early expressive communicative trajectories of infants/toddlers with early cochlear implants

For children with normal hearing (NH), early communication skills predict vocabulary, a precursor to grammar. Growth in early communication skills of infants with cochlear implants (CIs) was investigated using the Early Communication Indicator (ECI), a play-based observation measure. Multilevel linear growth modelling on data from six ECI sessions held at three-monthly intervals revealed significant growth overall, with a non-significant slower growth rate than that of children with NH (comparison age centred at 18 months). Analyses of gesture use and of nonword vocalisations revealed the CI group used significantly more of each, with more rapid growth. In contrast, the CI group used significantly fewer single words and multiword utterances, and with slower growth. Maternal education and time to achieve consistent CI use impacted significantly on growth for the CI sample. The results indicate that progression to vocabulary by young CI users can be supported by encouraging their use of prelinguistic communication.

Children with cochlear implants in infancy: predictors of early vocabulary

BACKGROUND

Language outcomes for children with cochlear implants (CIs) vary widely, even for those implanted before 2 years of age. Identifying the main influencing factors that account for some of the variability is important in order to provide information to guide appropriate clinical and intervention services for young children with CIs. However, there is limited research focusing on the predictors of early vocabulary development for children implanted in infancy.

AIMS

To identify significant predictors of vocabulary (12-15 months post-implant) for a sample of 33 children with CIs, the majority implanted between 6 and 10 months of age, drawing on predictors of vocabulary reported for children with normal hearing. Of particular interest was the impact of pre-implant development and use of gestures.

METHODS & PROCEDURES

Children with severe to profound hearing loss, and no other known disabilities, were recruited from CI clinics in Australia before receiving their CIs. Subscales from the Bayley Scales-III (receptive and expressive communication, gross and fine motor, and cognition) were used to assess their development at that time. Using the Macarthur-Bates Communicative Development Inventory (Words and Gestures) we documented the children's (1) use of gestures at six data-collection times 3 months apart; and (2) vocabulary at the last three time points. Time since implant and time to consistent use of the CIs were also included as potential predictors. Data were analysed using generalized linear models, assuming a negative binomial response with a log-link function. Stepwise variables selection was followed to retain a smaller number of the covariates.

OUTCOMES & RESULTS

A year after implantation, the significant predictors identified for vocabulary were pre-implant receptive communication and early gesture use. Together with fine motor and cognitive skills, these two variables were also significant predictors of vocabulary 3 months later. With maternal education entered into the models, higher vocabulary scores were significantly associated with higher maternal education 12 months post-implantation, but not 15 months.

CONCLUSIONS & IMPLICATIONS

Pre-implant abilities are important in explaining some variability in the early vocabulary of infants with CIs, together with their use of early gestures post-implantation. That is, having a non-verbal means to express a concept can assist in their development of oral vocabulary. Identifying strategies to help develop fine motor skills for infants with CIs, and encouraging their use of gestures to communicate their needs/intentions, are likely to be of benefit.

Language and social-emotional and behavioural wellbeing from 4 to 7 years: a community-based study

Language disorder (LD) and social-emotional and behavioural (SEB) difficulties are common childhood problems that often co-occur. While there is clear evidence of these associations from clinical samples, less is known about community samples. This paper examines these associations in children aged 4-7 years from a community-based longitudinal study. 771 families provided questionnaire and assessment data at 4, 5 and 7 years. Parent-reported SEB difficulties were measured at each point (SDQ). Child language was directly assessed at 4 (CELF-P2), 5 and 7 years (CELF-4). Linear regression analysis was used to compare cross-sectional differences in mean SDQ scores between children with and without LD at each time point. Linear regression was then used to examine how patterns of language development (language disordered at three time points; never disordered; disordered at one or two time points, i.e. 'unstable' group) related to SEB difficulties at each age, adjusted for potential confounders, as in the previous analyses. Higher hyperactivity/inattention scores were associated with LD at each age. In fully adjusted models, there was little difference in mean emotional symptoms scores between children with and without LD. The 'never' LD group had lower mean SDQ scores at each time point than the 'unstable' group. Findings highlight that children with persistent LD from preschool to early primary school may be more likely to have concomitant SEB difficulties, particularly behavioural difficulties. Those with unstable LD may also have co-occurring SEB difficulties, showing a need for education and health professionals to monitor early language and SEB development.

Service utilisation and costs of language impairment in children: The early language in Victoria Australian population-based study

PURPOSE

To examine (1) the patterns of service use and costs associated with language impairment in a community cohort of children from ages 4-9 years and (2) the relationship between language impairment and health service utilisation.

METHOD

Participants were children and caregivers of six local government areas in Melbourne participating in the community-based Early Language in Victoria Study (ELVS). Health service use was reported by parents. Costs were valued in Australian dollars in 2014, from the government and family perspectives. Depending on age, the Australian adapted Clinical Evaluation of Language Fundamentals - Pre-school, 2nd Edition (CELF-P2) or the CELF, 4th Edition (CELF4) was used to assess expressive and receptive language.

RESULT

At 5, 7 and 9 years respectively 21%, 11% and 8% of families reported using services for speech and/or language concerns. The annual costs associated with using services averaged A$612 (A$255 to government, A$357 to family) at 5 years and A$992 (A$317 to government, A$675 to family) at 7 years. Children with persistent language impairment had significantly higher service costs than those with typical language.

CONCLUSION

Language impairment in 4-9-year-old children is associated with higher use of services and costs to both families and government compared to typical language.

The Contribution of Phonological Awareness to Reading Fluency and Its Individual Sub-skills in Readers Aged 9- to 12-years

Research examining phonological awareness (PA) contributions to reading in established readers of different skill levels is limited. The current study examined the contribution of PA to phonological decoding, visual word recognition, reading rate, and reading comprehension in 124 fourth to sixth grade children (aged 9-12 years). On the basis of scores on the FastaReada measure of reading fluency participants were allocated to one of three reading ability categories: dysfluent (n = 47), moderate (n = 38) and fluent (n = 39). For the dysfluent group, PA contributed significantly to all reading measures except rate, but in the moderate group only to phonological decoding. PA did not influence performances on any of the reading measures examined for the fluent reader group. The results support the notion that fluency is characterized by a shift from conscious decoding to rapid and accurate visual recognition of words. Although PA may be influential in reading development, the results of the current study show that it is not sufficient for fluent reading.

Language Outcomes at 7 Years: Early Predictors and Co-Occurring Difficulties

OBJECTIVE

To examine at 7 years the language abilities of children, the salience of early life factors and language scores as predictors of language outcome, and co-occurring difficulties METHODS: A longitudinal cohort study of 1910 infants recruited at age 8 to 10 months. Exposures included early life factors (sex, prematurity, birth weight/order, twin birth, socioeconomic status, non-English speaking background,family history of speech/language difficulties); maternal factors (mental health, vocabulary, education, and age); and child language ability at 2 and 4 years. Outcomes were 7-year standardized receptive or expressive language scores (low language: ≥1.25 SD below the mean), and co-occurring difficulties (autism, literacy, social, emotional, and behavioral adjustment, and health-related quality of life).

RESULTS

Almost 19% of children (22/1204;18.9%) met criteria for low language at 7 years. Early life factors explained 9-13% of variation in language scores, increasing to 39-58% when child language scores at ages 2 and 4 were included. Early life factors moderately discriminated between children with and without low language (area under the curve: 0.68-0.72), strengthening to good discrimination with language scores at ages 2 and 4 (area under the curve: 0.85-0.94). Low language at age 7 was associated with concurrent difficulties in literacy, social-emotional and behavioral difficulties, and limitations in school and psychosocial functioning.

CONCLUSIONS

Child language ability at 4 years more accurately predicted low language at 7 than a range of early child, family, and environmental factors. Low language at 7 years was associated with a higher prevalence of co-occurring difficulties.

The Contributions of Memory and Vocabulary to Non-Verbal Ability Scores in Adolescents with Intellectual Disability

It is usually assumed that performance on non-verbal intelligence tests reflects visual cognitive processing and that aspects of working memory (WM) will be involved. However, the unique contribution of memory to non-verbal scores is not clear, nor is the unique contribution of vocabulary. Thus, we aimed to investigate these contributions. Non-verbal test scores for 17 individuals with intellectual disability (ID) and 39 children with typical development (TD) of similar mental age were compared to determine the unique contribution of visual and verbal short-term memory (STM) and WM and the additional variance contributed by vocabulary scores. No significant group differences were found in the non-verbal test scores or receptive vocabulary scores, but there was a significant difference in expressive vocabulary. Regression analyses indicate that for the TD group STM and WM (both visual and verbal) contributed similar variance to the non-verbal scores. For the ID group, visual STM and verbal WM contributed most of the variance to the non-verbal test scores. The addition of vocabulary scores to the model contributed greater variance for both groups. More unique variance was contributed by vocabulary than memory for the TD group, whereas for the ID group memory contributed more than vocabulary. Visual and auditory memory and vocabulary contributed significantly to solving visual non-verbal problems for both the TD group and the ID group. However, for each group, there were different weightings of these variables. Our findings indicate that for individuals with TD, vocabulary is the major factor in solving non-verbal problems, not memory, whereas for adolescents with ID, visual STM, and verbal WM are more influential than vocabulary, suggesting different pathways to achieve solutions to non-verbal problems.

Parent-reported patterns of loss and gain in communication in 1- to 2-year-old children are not unique to autism spectrum disorder

We compared loss and gain in communication from 1 to 2 years in children later diagnosed with autism spectrum disorder (n = 41), language impairment (n = 110) and in children with typical language development at 7 years (n = 831). Participants were selected from a prospective population cohort study of child language (the Early Language in Victoria Study). Parent-completed communication tools were used. As a group, children with autism spectrum disorder demonstrated slower median skill gain, with an increasing gap between trajectories compared to children with typical development and language impairment. A proportion from all groups lost skills in at least one domain (autism spectrum disorder (41%), language impairment (30%), typical development (26%)), with more children with autism spectrum disorder losing skills in more than one domain (autism spectrum disorder (47%), language impairment (15%, p = 0.0003), typical development (16%, p < 0.001)). Loss was most common for all groups in the domain of 'emotion and eye gaze' but with a higher proportion for children with autism spectrum disorder (27%; language impairment (12%, p = 0.03), typical development (14%, p = 0.03)). A higher proportion of children with autism spectrum disorder also lost skills in gesture (p = 0.01), sounds (p = 0.009) and understanding (p = 0.004) compared to children with typical development but not with language impairment. These findings add to our understanding of early communication development and highlight that loss is not unique to autism spectrum disorder.

Comparison of Measures of Ability in Adolescents with Intellectual Disability

Finding the most appropriate intelligence test for adolescents with Intellectual Disability (ID) is challenging given their limited language, attention, perceptual, and motor skills and ability to stay on task. The study compared performance of 23 adolescents with ID on the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), one of the most widely used intelligence tests, and three non-verbal IQ tests, the Raven's Colored Progressive Matrices (RCPM), the Test of Non-verbal Intelligence-Fourth Edition and the Wechsler Non-verbal test of Ability. Results showed that the WISC-IV Full Scale IQ raw and scaled scores were highly correlated with total scores from the three non-verbal tests, although the correlations were higher for raw scores, suggesting they may lead to better understanding of within group differences and what individuals with ID can do at the time of assessment. All participants attempted more questions on the non-verbal tests than the verbal. A preliminary analysis showed that adolescents with ID without ASD (n = 15) achieved higher scores overall than those presenting with ID+ASD (n = 8). Our findings support the view that short non-verbal tests are more likely to give a similar IQ result as obtained from the WISC-IV. In terms of the time to administer and the stress for participants, they are more appropriate for assessing adolescents with ID.

Young Children with ASD Use Lexical and Referential Information During On-line Sentence Processing

Research with adults and older children indicates that verb biases are strong influences on listeners' interpretations when processing sentences, but they can be overruled. In this paper, we ask two questions: (i) are children with Autism Spectrum Disorder (ASD) who are high functioning sensitive to verb biases like their same age typically developing peers?, and (ii) do young children with ASD and young children with typical development (TD) override strong verb biases to consider alternative interpretations of ambiguous sentences? Participants were aged 5-9 years (mean age 6.65 years): children with ASD who were high functioning and children with TD. In task 1, biasing and neutral verbs were included (e.g., eat cake versus move cake). In task 2, the focus was on whether the prepositional phrase occurring with an instrument biasing verb (e.g., 'Chop the tree with the axe') was interpreted as an instrument even if the named item was an implausible instrument (e.g., candle in 'Cut the cake with the candle'). Overall, the results showed similarities between groups but the ASD group was generally slower. In task 1, both groups looked at the named object faster in the biasing than the non-biasing condition, and in the biasing condition the ASD group looked away from the target more quickly than the TD group. In task 2, both groups identified the target in the prepositional phrase. They were more likely to override the verb instrument bias and consider the alternative (modification) interpretation in the implausible condition (e.g., looking at the picture of a cake with a candle on it'). Our findings indicate that children of age 5 years and above can use context to override verb biases. Additionally, an important component of the sentence processing mechanism is largely intact for young children with ASD who are high functioning. Like children with TD, they draw on verb semantics and plausibility in integrating information. However, they are likely to be slower in processing the language they hear. Based on previous findings of associations between processing speed and cognitive functioning, the implication is that their understanding will be negatively affected, as will their academic outcomes.

Preliminary validation of FastaReada as a measure of reading fluency

Fluent reading is characterized by speed and accuracy in the decoding and comprehension of connected text. Although a variety of measures are available for the assessment of reading skills most tests do not evaluate rate of text recognition as reflected in fluent reading. Here we evaluate FastaReada, a customized computer-generated task that was developed to address some of the limitations of currently available measures of reading skills. FastaReada provides a rapid assessment of reading fluency quantified as words read per minute for connected, meaningful text. To test the criterion validity of FastaReada, 124 mainstream school children with typical sensory, mental and motor development were assessed. Performance on FastaReada was correlated with the established Neale Analysis of Reading Ability (NARA) measures of text reading accuracy, rate and comprehension, and common single word measures of pseudoword (non-word) reading, phonetic decoding, phonological awareness (PA) and mode of word decoding (i.e., visual or eidetic versus auditory or phonetic). The results demonstrated strong positive correlations between FastaReada performance and NARA reading rate (r = 0.75), accuracy (r = 0.83) and comprehension (r = 0.63) scores providing evidence for criterion-related validity. Additional evidence for criterion validity was demonstrated through strong positive correlations between FastaReada and both single word eidetic (r = 0.81) and phonetic decoding skills (r = 0.68). The results also demonstrated FastaReada to be a stronger predictor of eidetic decoding than the NARA rate measure, with FastaReada predicting 14.4% of the variance compared to 2.6% predicted by NARA rate. FastaReada was therefore deemed to be a valid tool for educators, clinicians, and research related assessment of reading accuracy and rate. As expected, analysis with hierarchical regressions also highlighted the closer relationship of fluent reading to rapid visual word recognition than to phonological-based skills. Eidetic decoding was the strongest predictor of FastaReada performance (16.8%) followed by phonetic decoding skill (1.7%). PA did not make a unique contribution after eidetic decoding and phonetic decoding skills were accounted for.

Levers for Language Growth: Characteristics and Predictors of Language Trajectories between 4 and 7 Years

Background

Evidence is required as to when and where to focus resources to achieve the greatest gains for children’s language development. Key to these decisions is the understanding of individual differences in children’s language trajectories and the predictors of those differences. To determine optimal timing we must understand if and when children’s relative language abilities become fixed. To determine where to focus effort we must identify mutable factors, that is those with the potential to be changed through interventions, which are associated with significant differences in children’s language scores and rate of progress.

Methods

Uniquely this study examined individual differences in language growth trajectories in a population sample of children between 4 and 7 years using the multilevel model for change. The influence of predictors, grouped with respect to their mutability and their proximity to the child (least-mutable, mutable-distal, mutable-proximal), were estimated.

Results

A significant degree of variability in rate of progress between 4 and 7 years was evident, much of which was systematically associated with mutable-proximal factors, that is, those factors with evidence that they are modifiable through interventions with the child or family, such as shared book reading, TV viewing and number of books in the home. Mutable-distal factors, such as family income, family literacy and neighbourhood disadvantage, hypothesised to be modifiable through social policy, were important predictors of language abilities at 4 years.

Conclusions

Potential levers for language interventions lie in the child’s home learning environment from birth to age 4. However, the role of a family’s material and cultural capital must not be ignored, nor should the potential for growth into the school years. Early Years services should acknowledge the effects of multiple, cascading and cumulative risks and seek to promote child language development through the aggregation of marginal gains in the pre-school years and beyond.

Severity of autism is related to children's language processing

Problems in language processing have been associated with autism spectrum disorder (ASD), with some research attributing the problems to overall language skills rather than a diagnosis of ASD. Lexical access was assessed in a looking-while-listening task in three groups of 5- to 7-year-old children; two had high-functioning ASD (HFA), an ASD severe (ASD-S) group (n = 16) and an ASD moderate (ASD-M) group (n = 21). The third group were typically developing (TD) (n = 48). Participants heard sentences of the form "Where's the x?" and their eye movements to targets (e.g., train), phonological competitors (e.g., tree), and distractors were recorded. Proportions of looking time at target were analyzed within 200 ms intervals. Significant group differences were found between the ASD-S and TD groups only, at time intervals 1000-1200 and 1200-1400 ms postonset. The TD group was more likely to be fixated on target. These differences were maintained after adjusting for language, verbal and nonverbal IQ, and attention scores. An analysis using parent report of autistic-like behaviors showed higher scores to be associated with lower proportions of looking time at target, regardless of group. Further analysis showed fixation for the TD group to be significantly faster than for the ASD-S. In addition, incremental processing was found for all groups. The study findings suggest that severity of autistic behaviors will impact significantly on children's language processing in real life situations when exposed to syntactically complex material. They also show the value of using online methods for understanding how young children with ASD process language.

Natural history of stuttering to 4 years of age: a prospective community-based study

OBJECTIVES

To document the natural history of stuttering by age 4 years, including (1) cumulative incidence of onset, (2) 12-month recovery status, (3) predictors of stuttering onset and recovery, and (4) potential comorbidities. The study cohort was a prospective community-ascertained cohort (the Early Language in Victoria Study) from Melbourne, Australia, of 4-year-old children (n = 1619; recruited at age 8 months) and their mothers.

METHODS

Outcome was stuttering onset by age 4 years and recovery within 12 months of onset, defined using concurrent monthly parent and speech pathologist ratings. Potential predictors: child gender, birth weight, birth order, prematurity, and twinning; maternal mental health and education; socioeconomic status; and family history of stuttering. Potential comorbidities: preonset and concurrent temperament, language, nonverbal cognition, and health-related quality of life.

RESULTS

By age 4 years, the cumulative incidence of stuttering onset was 11.2% (95% confidence interval [CI]: 9.7% to 12.8%). Higher maternal education (P = .004), male gender (P = .02), and twinning (P = .005) predicted stuttering onset. At outcome, stuttering children had stronger language (mean [SD]: 105.0 [13.0] vs 99.6 [14.6]; mean difference 5.5, 95% CI: 3.1 to 7.8; P < .001) and nonverbal cognition (mean [SD]: 106.5 [11.4] vs 103.9 [13.7], mean difference 2.6, 95% CI: 0.4 to 4.8; P = .02) and better health-related quality of life but were otherwise similar to their nonstuttering peers. Only 9 of 142 children (6.3%; 95% CI: 2.9% to 11.7%) recovered within 12 months of onset.

CONCLUSIONS

Although stuttering onset is common in preschoolers, adverse affects are not the norm in the first year after onset.

Children with specific language impairment and resolved late talkers: working memory profiles at 5 years

PURPOSE

The evidence of a deficit in working memory in specific language impairment (SLI) is of sufficient magnitude to suggest a primary role in developmental language disorder. However, little research has investigated memory in late talkers who recover from their early delay. Drawing on a longitudinal, community sample, this study compared the memory profiles of 3 groups of 5-year-olds: children with SLI who had been identified as late talkers, resolved late talkers (RLTs), and children with typical language development (TLD).

METHOD

Participants were 25 children with SLI, 45 RLTs, and 32 children with TLD. Subtests from the Working Memory Test Battery for Children and the Children's Memory Scale plus recalling sentences and nonword repetition tasks were administered to test the components of Baddeley's working memory model.

RESULTS

The SLI group showed significantly poorer performance than the RLT and TLD groups on measures of the phonological loop and episodic buffer. The RLT and TLD groups scored similarly on all memory measures.

CONCLUSIONS

The results support previous findings that sentence recall and nonword repetition are markers of SLI. Although residual effects of late-talking status may emerge over time, RLTs do not necessarily show memory deficits at 5 years of age despite delayed early vocabulary development.

Profiles of language development in pre-school children: a longitudinal latent class analysis of data from the Early Language in Victoria Study

BACKGROUND

Pre-school language impairment is common and greatly reduces educational performance. Population attempts to identify children who would benefit from appropriately timed intervention might be improved by greater knowledge about the typical profiles of language development. Specifically, this could be used to help with the early identification of children who will be impaired on school entry.

METHODS

  This study applied longitudinal latent class analysis to assessments at 8, 12, 24, 36 and 48 months on 1113 children from a population-based study, in order to identify classes exhibiting distinct communicative developmental profiles.

RESULTS

Five substantive classes were identified: Typical, i.e. development in the typical range at each age; Precocious (late), i.e. typical development in infancy followed by high probabilities of precocity from 24 months onwards; Impaired (early), i.e. high probabilities of impairment up to 12 months followed by typical language development thereafter; Impaired (late), i.e. typical development in infancy but impairment from 24 months onwards; Precocious (early), i.e. high probabilities of precocity in early life followed by typical language by 48 months. The entropy statistic (0.84) suggested classes were fairly well defined, although there was a non-trivial degree of uncertainty in classification of children. That half of the Impaired (late) class was expected to have typical language at 4 years and 6% of the numerically large Typical class was expected to be impaired at 4 years illustrates this. Characteristics indicative of social advantage were more commonly found in the classes with improving profiles.

CONCLUSIONS

Developmental profiles show that some pre-schoolers' language is characterized by periods of accelerated development, slow development and catch-up growth. Given the uncertainty in classifying children into these profiles, use of this knowledge for identifying children who will be impaired on school entry is not straightforward. The findings do, however, indicate greater need for language enrichment programmes among disadvantaged children.

Narrative comprehension in 4-7-year-old children with autism: testing the Weak Central Coherence account

BACKGROUND

Despite somewhat spared structural language development in high-functioning autism, communicative comprehension deficits persist. Comprehension involves the integration of meaning: global processing is required. The Weak Central Coherence theory suggests that individuals with autism are biased to process information locally. This cognitive style may impair comprehension, particularly if inferencing is required. However, task performance may be facilitated by this cognitive style if local processing is required.

AIMS

The current study was designed to examine the extent to which the 'weak central coherence' cognitive style affects comprehension and inferential processing of spoken narratives. The children with autism were expected to perform comparatively poorer on inferences relating to event scripts and comparatively better on inferences requiring deductive reasoning.

METHODS & PROCEDURES

Fourteen high-functioning children with autism were recruited from databases of various autism organizations (mean age = 6:7, 13 males, one female) and were matched on a receptive vocabulary and a picture-completion task with 14 typically developing children recruited from a local childcare centre (mean age = 4:10, seven males, seven females). The children were read short stories and asked questions about the stories.

OUTCOMES & RESULTS

Results indicated that the children with autism were less able to make inferences based on event scripts, but the groups did not differ significantly on inferences requiring deductive logical reasoning. Despite similar group performance on questions relating to the main idea of the stories, only for the typically developing group was good performance on extracting the main idea of the narratives significantly correlated with performance on all other comprehension tasks.

CONCLUSIONS & IMPLICATIONS

Findings provide some support for the Weak Central Coherence theory and demonstrate that young children with autism do not spontaneously integrate information in order to make script inferences, as do typically developing children. These findings may help to explain communicative problems of young children with autism and can be applied to intervention programme development. More research on the link between a 'weak central coherence' cognitive style and communicative comprehension in autism will be valuable in understanding the comprehension deficits associated with autism.

Predictors of early precocious talking: a prospective population study

This study examines potential predictors of 'precocious talking' (expressive language ≥90th percentile) at one and two years of age, and of 'stability' in precocious talking across both time periods, drawing on data from a prospective community cohort comprising over 1,800 children. Logistic regression was used to examine the relationship between precocious talking and the following potential predictors: gender, birth order, birth weight, non-English speaking background, socioeconomic status, maternal age, maternal mental health scores, and vocabulary and educational attainment of parents. The strongest predictors of precocity (being female and having a younger mother) warrant further exploration. Overall, however, it appears that precocity in early vocabulary development is not strongly influenced by the variables examined, which together explained just 2.6% and 1% of the variation at 1;0 and 2;0 respectively.

Testing auditory processing skills and their associations with language in 4-5-year-olds

Infants' auditory processing abilities have been shown to predict subsequent language development. In addition, poor auditory processing skills have been shown for some individuals with specific language impairment. Methods used in infant studies are not appropriate for use with young children, and neither are methods typically used to test auditory processing skills in specific language language impairment (SLI). The objective in this study was to develop an appropriate way of testing auditory processing skills in children in the 4-5 year age range. We report data from 49 children aged 4-5 years (mean age 58.57 months) tested on five tasks with tones and synthesized syllables. Frequencies and inter-stimulus intervals were varied in the tone tasks; the second formant transitions between consonant and vowel were varied in the syllable tasks. Consistent with past research, variability was found in children's auditory processing abilities. Significant correlations in discrimination thresholds for the tasks were found. The results from two regression analyses showed that the children's auditory processing abilities predicted significant amounts of variance for receptive and expressive language.

Predicting stuttering onset by the age of 3 years: a prospective, community cohort study

OBJECTIVES

Our goals were to document (1) the onset of stuttering and (2) whether specific child, family, or environmental factors predict stuttering onset in children aged up to 3 years.

METHODS

Participants included a community-ascertained cohort of 1619 2-year-old Australian children recruited at 8 months of age to study the longitudinal development of early language. The main outcome measure was parental telephone report of stuttering onset, verified by face-to-face expert diagnosis. Preonset continuous measures of the child's temperament (approach/withdrawal) and language development were available. Information on a range of predictor measures hypothesized to be associated with stuttering onset was obtained (maternal mental health and education levels, gender, premature birth status, birth weight, birth order, twinning, socioeconomic status, family history of stuttering).

RESULTS

By 3 years of age, the cumulative incidence of stuttering onset was 8.5%. Onset often occurred suddenly over 1 to 3 days (49.6%) and involved the use of word combinations (97.1%). Children who stuttered were not more shy or withdrawn. Male gender, twin birth status, higher vocabulary scores at 2 years of age, and high maternal education were associated with stuttering onset. The multivariable model, however, had low predictive strength; just 3.7% of the total variation in stuttering onset was accounted for.

CONCLUSIONS

The cumulative incidence of stuttering onset was much higher than reported previously. The hypothesized risk factors for stuttering onset together explained little of the variation in stuttering onset up to 3 years of age. Early onset was not associated with language delay, social and environmental factors, or preonset shyness/withdrawal. Health professionals can reassure parents that onset is not unusual up to 3 years of age and seems to be associated with rapid growth in language development.

The Early Language in Victoria Study: predicting vocabulary at age one and two years from gesture and object use

The Macarthur-Bates Communicative Development Inventories (CDI) have been used widely to document early communicative development. The paper reports on a large community sample of 1,447 children recruited from low, middle and high socioeconomic (SES) areas across metropolitan Melbourne, Australia. Regression analyses were conducted to determine the extent to which communicative behaviours reported at 0 ; 8 and 1 ; 0 predicted vocabulary development at 1 ; 0 and 2 ; 0. In support of previous findings with smaller, often less representative samples, gesture and object use at 1 ; 0 were better predictors of 2 ; 0 vocabulary than were gesture and object use at 0 ; 8. At 1 ; 0, children from the lower SES groups were reported to understand more words than children from the higher SES groups, but there were no SES differences for words produced at 1 ; 0 or 2 ; 0. The findings add to our understanding of the variability in the development of early communicative behaviours.

Children with specific language impairment: an investigation of their narratives and memory

BACKGROUND

Narratives have been used by a number of researchers to investigate the language of children with specific language impairment (SLI). While a number of explanations for SLI have been proposed, there is now mounting evidence that children with SLI have limited memory resources. Phonological memory has been the focus of the research on memory with this population. However, the use of narrative tasks to investigate memory limitations in SLI has not previously been undertaken.

AIMS

The aims of the research were to investigate the narrative and memory abilities of 6-year-old children with SLI and the association between narrative skills and memory.

METHODS & PROCEDURES

Two studies were conducted. In Study 1 the performance of the children with SLI was compared with that of their peers with typical language development (AM), and to that of a younger group (LM) matched on expressive language (about 2 years younger). Children were asked to recall ('story recall') and show comprehension of a narrative they had been told, and also to tell a story based on a series of pictures ('story generation'), to recall their story and to answer comprehension questions about it. In Study 2 the children with SLI from Study 1 and the AM children from Study 1 were tested on four working memory tasks: word and digit span, the Recalling Sentences task from the Clinical Evaluation of Language Fundamentals--Third Edition, and a dual-processing task. An inhibition task and an attention task were also included. It was predicted that children with SLI would perform more poorly than the AM group on measures of narrative telling, but comparably with the LM group. It was also predicted that the SLI group would perform more poorly than the AM group on both literal and inferencing comprehension questions but comparably with the LM group. The third prediction was that there would be significant associations between children's performance on the narrative tasks and the tasks measuring working memory.

OUTCOMES & RESULTS

In Study 1 the children with SLI performed more like the younger group on recall of a narrative they had heard, but more like their peers when asked to generate and recall their own narrative based on a series of pictures. The children with SLI had difficulty with inferencing questions. In Study 2 the impaired group performed significantly worse on measures of memory, showing a lower working memory capacity. The children with SLI made more errors on the attention task, but no group differences were found on the inhibition task. In comparing results from Studies 1 and 2, significant correlations were found between performance on the narrative tasks and memory tasks, but the contribution of memory to the narrative task scores differed for the two stories. The Recalling Sentences memory task was found to be the best overall measure for predicting variance on story comprehension and recall.

CONCLUSIONS

In support of previous research, the children with SLI showed problems with inferencing, linking directly observed or stated information to likely outcomes. They also showed a limited working memory capacity, and they were more likely to make errors in attention. A main finding was that the narrative abilities of the 6-year-old children were linked to their verbal working memory. The information the SLI group heard was harder to access than information they had been able to generate themselves based on a series of pictures. The findings suggest that children with SLI are likely to be at a disadvantage in classroom situations, particularly for information presented aurally and if the information is complex. The use of pictorial aids may help them encode the information. They would also benefit from having information broken into manageable units.

Analysis and control in children with SLI

PURPOSE

E. Bialystok and E. B. Ryan (1985) have outlined two operations, analysis and control, which are required for grammaticality judgments. In this model, analysis is involved in determining the grammaticality of a sentence, and control is required so that irrelevant information is ignored. This study examined these processes in specific language impairment (SLI).

METHOD

Sixteen children with SLI and 20 typically developing (TD) children between 8;6 (years;months) and 10;6 were presented with a grammatical judgment task. Analysis was measured by recording children's decision times in determining grammaticality. Control was assessed by examining accuracy for judgments made for semantically odd sentences.

RESULTS

Relative to the TD group, it was found that the children with SLI took longer in judging sentences associated with the process of analysis. Children with SLI were also found to have more difficulty, in terms of accuracy, with items requiring control (e.g., semantically odd sentences) than did the TD group.

CONCLUSION

It is argued that the longer time required for children with SLI to respond to semantically normal sentences reflects a degree of difficulty with completing analysis. The SLI group's lower level of accuracy on semantically odd sentences reflects a problem with a control and is consistent with previously reported problems with cognitive inhibition in SLI.

Predicting language at 2 years of age: a prospective community study

OBJECTIVE

This article responds to evidence gaps regarding language impairment identified by the US Preventive Services Task Force in 2006. We examine the contributions of putative child, family, and environmental risk factors to language outcomes at 24 months of age.

METHODS

A community-ascertained sample of 1720 infants who were recruited at 8 months of age were followed at ages 12 and 24 months in a prospective, longitudinal study in metropolitan Melbourne, Australia. Outcomes at 24 months were parent-reported infant communication (Communication and Symbolic Behavior Scales and MacArthur-Bates Communicative Development Inventories vocabulary production score). Putative risk factors were gender, preterm birth, birth weight, multiple birth, birth order, socioeconomic status, maternal mental health, maternal vocabulary and education, maternal age at birth of child, non-English-speaking background, and family history of speech-language difficulties. Linear regression models were fitted to total standardized Communication and Symbolic Behavior Scales and Communicative Development Inventories vocabulary production scores; a logistic regression model was fitted to late-talking status at 24 months.

RESULTS

The regression models accounted for 4.3% and 7.0% of the variation in the 24-month Communication and Symbolic Behavior Scales and Communicative Development Inventories scores, respectively. Male gender and family history were strongly associated with poorer outcomes on both instruments. Lower Communication and Symbolic Behavior Scales scores were also associated with lower maternal vocabulary and older maternal age. Lower vocabulary production scores were associated with birth order and non-English-speaking background. When the 12-month Communication and Symbolic Behavior Scales Total score was added as a covariate in the linear regression of 24-month Communication and Symbolic Behavior Scales Total score, it was by far the strongest predictor.

CONCLUSIONS

These early risk factors explained no more than 7% of the variation in language at 24 months. They seem unlikely to be helpful in screening for early language delay.

Growth of infant communication between 8 and 12 months: a population study

AIM

To describe changes in infant prelinguistic communication skills between 8 and 12 months, and identify factors associated with those skills.

DESIGN

Parent questionnaire data for a prospective population-based cohort of infants in metropolitan Melbourne, Australia.

PARTICIPANTS

1911 infants born November 2002-August 2003.

OUTCOME

Infant communication (Communication and Symbolic Behaviour Scales (CSBS)) at 8 and 12 months. Potential risk factors: sex; prematurity; multiple birth; sociodemographic indicators; maternal mental health, vocabulary and education; non-English speaking background; and family history of speech-language difficulties. Linear regression models were fitted to total standardised CSBS scores at 8 and 12 months.

RESULTS

Social communication, especially the use of gesture, developed rapidly from 8 to 12 months. Female sex, twin birth, and family history were strongly associated with CSBS scores. The combined model accounted for 5% and 6% of the total variation at 8 and 12 months, respectively. CSBS score at 8 months strongly predicted CSBS score at 12 months (coefficient = 0.56, partial R(2) = 37.0).

CONCLUSIONS

There is a dramatic increase in communication skills between 8 and 12 months, particularly the development of gesture, which (as in previous studies) predates and predicts future language development. Risk factors explained little variation in early communication trajectories and therefore, based on our findings, this developmental course is more likely to be biologically predetermined. Rather than focusing on risk factors, we suggest that language promotion activities in otherwise healthy young infants should either be universal or, if targeted, be based on the level of communication skills displayed.

Lexical and referential cues to sentence interpretation: an investigation of children's interpretations of ambiguous sentences

This paper reports on an investigation of children's (aged 3;5-9;8) comprehension of sentences containing ambiguity of prepositional phrase (PP) attachment. Results from a picture selection study (N = 90) showed that children use verb semantics and preposition type to resolve the ambiguity, with older children also showing sensitivity to the definiteness of the object NP as a cue to interpretation. Study 2 investigated three- and five-year-old children's (N = 47) ability to override an instrumental interpretation of ambiguous PPs in order to process attributes of the referential scene. The results showed that while five-year-olds are capable of incorporating aspects of the referential scene into their interpretations, three-year-olds are not as successful. Overall, the results suggest that children are attuned very early to the lexico-semantic co-occurrences that have been shown to aid ambiguity resolution in adults, but that more diffuse cues to interpretation are used only later in development.

Toddlers recognize verbs in novel situations and sentences

Toddlers' (MA=22 and 27 months) ability to extend newly taught verbs to new situational and sentential contexts was investigated. Children were interactively taught two novel verbs, presented in only the transitive frame (e.g. You're lorping the ball), in a playroom setting. They then viewed the verb actions presented on side-by-side monitors and were asked to distinguish the verbs in three test frames (transitive, intransitive, neutral (e.g. lorping)). Both groups demonstrated learning of the verbs in the new situation and generalized the verbs to the intransitive sentence frame, but neither generalized reliably to the neutral frame. We conclude that even 22-month-olds demonstrate considerable context independence in their verb representations.

Spatio-visual memory of children with specific language impairment: evidence for generalized processing problems

BACKGROUND

Children with Specific language Impairment (SLI) have problems with verbal memory, particularly with tasks that have more processing demands. They also have slower speeds of responding for some tasks.

AIMS

To identify the extent to which young children with SLI would differ in performance from age-matched non-impaired children on a set of spatio-visual memory tasks. It was predicted that if memory limitations of children with SLI extend beyond the verbal domain to other domains, their performance would be significantly poorer on the spatio-visual tasks than that of the comparison group. It was also predicted that they would be slower in responding.

METHODS & PROCEDURES

Six spatio-visual tasks were used to compare the performance of 21 children with SLI, with a mean age of 54.1 months, and 21 age-matched non-impaired children. The tasks ranged in difficulty from simple recall to a search-based working memory task. All tasks were administered though a laptop computer and responses were non-verbal using a touch screen.

OUTCOMES & RESULTS

The children with SLI were not significantly slower than the comparison group. However, they were significantly less accurate than the comparison group in recalling patterns, but not in recalling locations. The accuracy for both groups was lower on spatial recall than on pattern recall. The children with SLI were also significantly less able to learn to associate a particular pattern with a particular location, and to have a shorter spatial span. However, on a spatial search task testing working memory, the groups did not differ significantly.

CONCLUSIONS

The results indicate that the memory limitations of children with SLI are not restricted to verbal memory, and this fact has implications for its aetiology. Intervention programmes for young children with SLI need to extend beyond language in order to help them develop strategies for processing information in different situations.

English-speaking children's comprehension of relative clauses: evidence for general-cognitive and language-specific constraints on development

Children must possess some ability to process input in a meaningful manner to acquire language. The present study reports on data from an experiment investigating 3- to 5-year-old English-speaking children's understanding of restrictive relative clauses manipulated for embeddedness and focus. The results of the study showed that English-speaking children acquire right-branching before center-embedded structures. Comparisons made with data from Portuguese-speaking children suggest general-cognitive and language-specific constraints on development, and with respect to English, a "clause expansion" approach to processing in development.