Variability In Language Outcomes Research Articles

Turkish-German heritage speakers' predictive use of case: webcam-based vs. in-lab eye-tracking.

Recently, Özge et al. have argued that Turkish and German monolingual 4-year-old children can interpret case-marking predictively disregarding word order. Heritage speakers (HSs) acquire a heritage language at home and a majority societal language which usually becomes dominant after school enrollment. Our study directly compares two elicitation modes: in-lab and (remote) webcam-based eye-tracking data collection. We test the extent to which in-lab effects can be replicated in webcam-based eye-tracking using the exact same design. Previous research indicates that Turkish HSs vary more in the comprehension and production of case-marking compared to monolinguals. Data from 49 participants-22 Turkish monolinguals and 27 HSs-were analyzed using a binomial generalized linear mixed-effects regression model. In the Accusative condition, participants looked for the suitable Agent before it is appeared in speech. In the Nominative condition, participants looked for the suitable Patient before it is appeared in speech. HSs were able to use morphosyntactic cues on NP1 to predict the thematic role of NP2. This study supports views in which core grammatical features of languages, such as case, remain robust in HSs, in line with the Interface Hypothesis. We were able to replicate the effect of the predictive use of case in monolinguals using webcam-based eye-tracking, but the replication with heritage speakers was not successful due to variability in data collection contexts. A by-participant analysis of the results revealed individual variation in that there were some speakers who do not use case-marking predictively in the same way as most monolinguals and most HSs do. These findings suggest that the predictive use of case in heritage speakers is influenced by different factors, which may differ across individuals and affect their language abilities. We argue that HSs should be placed on a native-speaker continuum to explain variability in language outcomes.

Variability in Quantity and Quality of Early Linguistic Experience in Children With Cochlear Implants: Evidence from Analysis of Natural Auditory Environments.

Understanding how quantity and quality of language input vary across children with cochlear implants (CIs) is important for explaining sources of large individual differences in language outcomes of this at-risk pediatric population. Studies have mostly focused either on intervention-related, device-related, and/or patient-related factors, or relied on data from parental reports and laboratory-based speech corpus to unravel factors explaining individual differences in language outcomes among children with CIs. However, little is known about the extent to which children with CIs differ in quantity and quality of language input they experience in their natural linguistic environments. To address this knowledge gap, the present study analyzed the quantity and quality of language input to early-implanted children (age of implantation <23 mo) during the first year after implantation. Day-long Language ENvironment Analysis (LENA) recordings, derived from home environments of 14 early-implanted children, were analyzed to estimate numbers of words per day, type-token ratio (TTR), and mean length of utterance in morphemes (MLUm) in adults' speech. Properties of language input were analyzed across these three dimensions to examine how input in home environments varied across children with CIs in quantity, defined as number of words, and quality, defined as whether speech was child-directed or overheard. Our per-day estimates demonstrated that children with CIs were highly variable in the number of total words (mean ± SD = 25,134 ± 9,267 words) and high-quality child-directed words (mean ± SD = 10,817 ± 7,187 words) they experienced in a day in their home environments during the first year after implantation. The results also showed that the patterns of variability across children in quantity and quality of language input changes depending on whether the speech was child-directed or overheard. Children also experienced highly different environments in terms of lexical diversity (as measured by TTR) and morphosyntactic complexity (as measured by MLUm) of language input. The results demonstrated that children with CIs varied substantially in the quantity and quality of language input experienced in their home environments. More importantly, individual children experienced highly variable amounts of high-quality, child-directed speech, which may drive variability in language outcomes across children with CIs. Analyzing early language input in natural, linguistic environments of children with CIs showed that the quantity and quality of early linguistic input vary substantially across individual children with CIs. This substantial individual variability suggests that the quantity and quality of early linguistic input are potential sources of individual differences in outcomes of children with CIs and warrant further investigation to determine the effects of this variability on outcomes.

Beyond talk: Contributions of quantity and quality of communication to language success across socioeconomic strata

Infants from low-socioeconomic status (SES) households hear a projected 30 million fewer words than their higher-SES peers. In a recent study, Hirsh-Pasek et al. (Psychological Science, 2015; 26: 1071) found that in a low-income sample, fluency and connectedness in exchanges between caregivers and toddlers predicted child language a year later over and above quantity of talk (Hirsh-Pasek et al., Psychological Science, 2015; 26: 1071). Here, we expand upon this study by examining fluency and connectedness in two higher-SES samples. Using data from the NICHD Study of Early Child Care and Youth Development, we sampled 20 toddlers who had low, average, and high language outcomes at 36months from each of 2 groups based on income-to-needs ratio (INR; middle and high) and applied new coding to the mother-toddler interaction at 24months. In the high-INR group, the quality of mother-toddler interaction at 24months accounted for more variability in language outcomes a year later than did quantity of talk, quality of talk, or sensitive parenting. These results could not be accounted for by child language ability at 24months. These effects were not found in the middle-INR sample. Our findings suggest that when the quality of interaction, fluency and connectedness, predicts language outcomes, it is a robust relation, but it may not be universal.

Auditory and Visual Electrophysiology of Deaf Children with Cochlear Implants: Implications for Cross-modal Plasticity.

Deaf children who receive a cochlear implant early in life and engage in intensive oral/aural therapy often make great strides in spoken language acquisition. However, despite clinicians’ best efforts, there is a great deal of variability in language outcomes. One concern is that cortical regions which normally support auditory processing may become reorganized for visual function, leaving fewer available resources for auditory language acquisition. The conditions under which these changes occur are not well understood, but we may begin investigating this phenomenon by looking for interactions between auditory and visual evoked cortical potentials in deaf children. If children with abnormal auditory responses show increased sensitivity to visual stimuli, this may indicate the presence of maladaptive cortical plasticity. We recorded evoked potentials, using both auditory and visual paradigms, from 25 typical hearing children and 26 deaf children (ages 2–8 years) with cochlear implants. An auditory oddball paradigm was used (85% /ba/ syllables vs. 15% frequency modulated tone sweeps) to elicit an auditory P1 component. Visual evoked potentials (VEPs) were recorded during presentation of an intermittent peripheral radial checkerboard while children watched a silent cartoon, eliciting a P1–N1 response. We observed reduced auditory P1 amplitudes and a lack of latency shift associated with normative aging in our deaf sample. We also observed shorter latencies in N1 VEPs to visual stimulus offset in deaf participants. While these data demonstrate cortical changes associated with auditory deprivation, we did not find evidence for a relationship between cortical auditory evoked potentials and the VEPs. This is consistent with descriptions of intra-modal plasticity within visual systems of deaf children, but do not provide evidence for cross-modal plasticity. In addition, we note that sign language experience had no effect on deaf children’s early auditory and visual ERP responses.

Monitoring children's language development following intrathecal chemotherapy for acute lymphoblastic leukaemia

The majority of children diagnosed with acute lymphoblastic leukaemia (ALL) become long-term survivors. Hence, much emphasis is placed on optimising survivorship. Previous studies have used point-in-time language assessments to describe language outcomes subsequent to intrathecal chemotherapy (ITC), but this method of monitoring may be misleading in the absence of pre-morbid performance data. In the current study, we demonstrate the use of developmental trajectories to individually track the language development of eight children (M age at diagnosis = 4.8 years; M age at initial language assessment = 7.6 years) with a history of ALL treated with ITC. Basic and high-level language skills were assessed at a minimum of two assessment points over 2 years. Local comparative data were obtained from age- and sex-matched control participants (M age at initial assessment = 7.10 years). The skill development relevant to each test was tracked over time using the raw scores attained by each child treated for ALL, the average raw scores of his/her control group, and the test's raw scores at the 50th percentile (test average). Results revealed variability in language outcomes. With long-term negative impacts of chemotherapy calling for extended monitoring of children post-treatment, the use of developmental trajectories to track language development over time serves as an efficient, sensitive tool for providing follow-up services for children treated with ITC. Individualised language intervention can promptly commence when a child's performance deviates from expected trajectories.

Influence of implantation age on school-age language performance in pediatric cochlear implant users

Objective: This study examined specific spoken language abilities of 160 children with severe-to-profound sensorineural hearing loss followed prospectively 4, 5, or 6 years after cochlear implantation. Study sample: Ninety-eight children received implants before 2.5 years, and 62 children received implants between 2.5 and 5 years of age. Design: Language was assessed using four subtests of the Comprehensive Assessment of Spoken Language (CASL). Standard scores were evaluated by contrasting age of implantation and follow-up test time. Results: Children implanted under 2.5 years of age achieved higher standard scores than children with older ages of implantation for expressive vocabulary, expressive syntax, and pragmatic judgments. However, in both groups, some children performed more than two standard deviations below the standardization group mean, while some scored at or well above the mean. Conclusions: Younger ages of implantation are associated with higher levels of performance, while later ages of implantation are associated with higher probabilities of continued language delays, particularly within subdomains of grammar and pragmatics. Longitudinal data from this cohort study demonstrate that after 6 years of implant experience, there is large variability in language outcomes associated with modifiers of rates of language learning that differ as children with implants age.

Attention to speech sounds in normal-hearing and deaf children with cochlear implants.

Cochlear implantation (CI) is a treatment for severe-to-profound hearing loss in congenitally deaf children. Although there is very little variability in auditory thresholds among CI recipients, there is a large amount of variability in language outcomes. One possible source of variability in language outcomes is individual differences in attention and cognitive processes, which may be affected by early auditory deprivation. The effect of auditory deprivation on attention to auditory input was investigated by comparing attention to speech sounds in 23 young deaf children with CIs and 23 normal-hearing age-match controls. The deaf children received their CIs between 6 and 23 months and were tested several times during the first 1.5 years after implantation. Participants were seated on their caregiver’s lap in front of a TV monitor. On each trial, they were presented with a checkerboard pattern and either silence or a repeating speech sound. Normal-hearing children looked longer at the checkerboard during the sound trials at the youngest ages whereas CI children were delayed in showing a preference for the sound trials. Moreover, performance on this task correlated with language outcome measures taken two years later, suggesting that attention to speech sounds after implantation is predictive of later language development.

Contribution of Implicit Sequence Learning to Spoken Language Processing: Some Preliminary Findings With Hearing Adults

Spoken language consists of a complex, sequentially arrayed signal that contains patterns that can be described in terms of statistical relations among language units. Previous research has suggested that a domain-general ability to learn structured sequential patterns may underlie language acquisition. To test this prediction, we examined the extent to which implicit sequence learning of probabilistically structured patterns in hearing adults is correlated with a spoken sentence perception task under degraded listening conditions. Performance on the sentence perception task was found to be correlated with implicit sequence learning, but only when the sequences were composed of stimuli that were easy to encode verbally. Implicit learning of phonological sequences thus appears to underlie spoken language processing and may indicate a hitherto unexplored cognitive factor that may account for the enormous variability in language outcomes in deaf children with cochlear implants. The present findings highlight the importance of investigating individual differences in specific cognitive abilities as a way to understand and explain language in deaf learners and, in particular, variability in language outcomes following cochlear implantation.

Childhood Development after Cochlear Implantation (CDaCI) study: Design and baseline characteristics

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study.A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes.This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterize potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation. Copyright © 2007 John Wiley & Sons, Ltd.

Childhood Development after Cochlear Implantation (CDaCI) study: Design and baseline characteristics

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study.A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes.This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterize potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation. Copyright © 2007 John Wiley & Sons, Ltd.