Reading Development in Children With Cochlear Implants Who Communicate via Spoken Language: A Psycholinguistic Investigation

The use of a computer-based program focused on the syllabic method to support early literacy in children with cochlear implants

BACKGROUND

Children with cochlear implants (CIs) often lag behind children with normal hearing (NH) in early literacy skills. Furthermore, the development of language skills associated with their emergent literacy skills seems to depend on good auditory access. Supporting language acquisition and early literacy in children with CIs may prevent difficulties in primary school. The use of technology may facilitate auditory and speech recovery in children with CIs, but evidence on computer-based early literacy programs is limited.

OBJECTIVE

This study investigates (a) the effects of a computer-based program focusing on the syllabic method on the literacy skills of children with CIs (CIs group), comparing them with the literacy skills of a group of age-matched NH (normal hearing) peers (NHs group); (b) the associations between language and early literacy skills in the NHs group and between language, auditory and early literacy skills in the CIs group.

METHOD

Nine prelingually deaf children with CIs (M = 61.11, SD = 6.90) with severe to profound sensorineural hearing loss and nine age-matched NH children participated in the program. Categories of Auditory Performance (CAP) as measures of children's auditory skills were collected. All participants were tested on phonological, morphosyntax (grammatical comprehension and repetition), and early literacy skills (syllable blending and segmentation, syllable and word reading) (T1). Next, all children participated in the computer-based program for 12 weeks. After the program was completed (T2), only early literacy tests were administered to the children.

RESULTS

Although, on average, both groups obtained higher scores in all literacy tasks at T2, the CIs group scored lower than the NHs group. In the CIs group, at T2 we found significant improvements in syllable segmentation (p = 0.042) and word reading (p = 0.035). In the NHs group, at T2 we found significant improvements in syllable segmentation (p = 0.034), syllable blending (p = 0.022), syllable reading (p = 0.008), and word reading (p = 0.009). We also found significant associations in both groups between measures of morphosyntax at T1 and measures of early literacy at T2. In addition, for the CIs group, we found significant associations between children's auditory performance at T1 and measures of morphosyntax at T1 and early literacy at T2.

CONCLUSION

a computer-based program focused on the syllabic method could support children with CIs in acquiring emergent literacy abilities. The auditory performance of children with CIs seems to influence their morphosyntax and later early literacy skills.

Semantic processing in children with Cochlear Implants: A review of current N400 studies and recommendations for future research

Deaf and hard of hearing children with cochlear implants (CI) often display impaired spoken language skills. While a large number of studies investigated brain responses to sounds in this population, relatively few focused on semantic processing. Here we summarize and discuss findings in four studies of the N400, a cortical response that reflects semantic processing, in children with CI. A study with auditory target stimuli found N400 effects at delayed latencies at 12 months after implantation, but at 18 and 24 months after implantation effects had typical latencies. In studies with visual target stimuli N400 effects were larger than or similar to controls in children with CI, despite lower semantic abilities. We propose that in children with CI, the observed large N400 effect reflects a stronger reliance on top-down predictions, relative to bottom-up language processing. Recent behavioral studies of children and adults with CI suggest that top-down processing is a common compensatory strategy, but with distinct limitations such as being effortful. A majority of the studies have small sample sizes (N < 20), and only responses to image targets were studied repeatedly in similar paradigms. This precludes strong conclusions. We give suggestions for future research and ways to overcome the scarcity of participants, including extending research to children with conventional hearing aids, an understudied group.

Modulations of right hemisphere connectivity in young children relates to the perception of spoken words

The early school years shape a young brain's capability to comprehend and contextualize words within milliseconds of exposure. Parsing word sounds (phonological interpretation) and word recognition (enabling semantic interpretation) are integral to this process. Yet little is known about the causal mechanisms of cortical activity during these early developmental stages. In this study, we aimed to explore these causal mechanisms via dynamic causal modelling of event-related potentials (ERPs) acquired from 30 typically developing children (ages 6-8 years) as they completed a spoken word-picture matching task. Source reconstruction of high-density electroencephalography (128 channels) was used to ascertain differences in whole-brain cortical activity during semantically "congruent" and "incongruent" conditions. Source activations analyzed during the N400 ERP window identified significant regions-of-interest (p_FWE<.05) localized primarily in the right hemisphere when contrasting congruent and incongruent word-picture stimuli. Dynamic causal models (DCMs) were tested on source activations in the fusiform gyrus (rFusi), inferior parietal lobule (rIPL), inferior temporal gyrus (rITG) and superior frontal gyrus (rSFG). DCM results indicated that a fully connected bidirectional model with self-(inhibiting) connections over rFusi, rIPL and rSFG provided the highest model evidence, based on exceedance probabilities derived from Bayesian statistical inferences. Connectivity parameters of rITG and rSFG regions from the winning DCM were negatively correlated with behavioural measures of receptive vocabulary and phonological memory (p_FDR<.05), such that lower scores on these assessments corresponded with increased connectivity between temporal pole and anterior frontal regions. The findings suggest that children with lower language processing skills required increased recruitment of right hemisphere frontal/temporal areas during task performance.

Listening comprehension in profoundly deaf children with cochlear implants: the role of auditory perception and foundational linguistic and cognitive skills

PURPOSE

The aim of the study was to investigate the listening comprehension (LC) skills in deaf and hard of hearing children (DHH) using cochlear implants (CI). Besides, personal and audiological variables that could influence the levels of competence reached were analyzed.

METHODS

Thirty-four children using CI were enrolled. LC skills were assessed through the standardized Italian test "Comprensione Orale-Test e Trattamento" (CO-TT). A univariate analysis was conducted to compare LC with gender, listening mode (unilateral or bilateral), maternal level of education and family income. A bivariate analysis was performed to search possible connections between children's performances and their individual characteristics, audiological conditions, and language levels. Finally, a multivariate analysis was performed using a stepwise hierarchical linear regression model which included all variables whose p value resulted  ≤ 0.05.

RESULTS

Twenty-one children using CI (61.8%) showed adequate performances in terms of chronological age, while 13 (38.2%) showed difficulties in LC. Maternal level of education, age at diagnosis and non-verbal cognitive level accounted for 43% of the observed variance. Auditory attention skills explained an additional 15% of variance. Morphosyntactic comprehension added a further 12% of variance.

CONCLUSION

CI can really help many DHH children to reach adequate LC skills, but in some cases difficulties remain. Factors influencing LC need to be early investigated and considered when planning an appropriate rehabilitative intervention.

Disparate Oral and Written Language Abilities in Adolescents With Cochlear Implants: Evidence From Narrative Samples

PURPOSE

In spite of improvements in language outcomes for children with hearing loss (HL) arising from cochlear implants (CIs), these children can falter when it comes to academic achievement, especially in higher grades. Given that writing becomes increasingly relevant to educational pursuits as children progress through school, this study explored the hypothesis that one challenge facing students with CIs may be written language.

METHOD

Participants were 98 eighth graders: 52 with normal hearing (NH) and 46 with severe-to-profound HL who used CIs. Oral and written narratives were elicited and analyzed for morphosyntactic complexity and global narrative features. Five additional measures were collected and analyzed as possible predictors of morphosyntactic complexity: Sentence Comprehension of Syntax, Grammaticality Judgment, Expressive Vocabulary, Forward Digit Span, and Phonological Awareness.

RESULTS

For oral narratives, groups performed similarly on both morphosyntactic complexity and global narrative features; for written narratives, critical differences were observed. Compared with adolescents with NH, adolescents with CIs used fewer markers of morphosyntactic complexity and scored lower on several global narrative features in their written narratives. Adolescents with NH outperformed those with CIs on all potential predictor measures, except for Sentence Comprehension of Syntax. Moderately strong relationships were found between predictor variables and individual measures of morphosyntactic complexity, but no comprehensive pattern explained the results. Measures of morphosyntactic complexity and global narrative features were not well correlated, suggesting these measures are assessing separate underlying constructs.

CONCLUSIONS

Adolescents with CIs fail to show writing proficiency at high school entry equivalent to that of their peers with NH, which could constrain their academic achievement. Interventions for children with CIs need to target writing skills, and writing assessments should be incorporated into diagnostic assessments.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.17139059.

Meta-Analytic Findings on Reading in Children With Cochlear Implants

This meta-analysis study aims to quantify the group differences in reading skills between children with cochlear implants and their hearing peers and between children with cochlear implants and children with hearing aids (aged between 3 and 18 years old). Of the 5,642 articles screened, 47 articles met predetermined inclusion criteria (published between 2002 and 2019). The robust variance estimation based meta-analysis models were used to synthesize all the effect sizes. Children with cochlear implants scored significantly lower than their hearing peers in phonological awareness (g = -1.62, p < 0.001), vocabulary (g = -1.50, p < 0.001), decoding (g = -1.24, p < 0.001), and reading comprehension (g = -1.39, p < 0.001), but not for fluency (g = -0.67, p = 0.054). Compared to children with hearing aids, children with cochlear implants scored significantly lower in phonological awareness (g = -0.30, p = 0.028). The percentage of unilateral cochlear implant negatively impacts the group difference between children with cochlear implants and their hearing peers. Findings from this study confirm a positive shift in reading outcomes for profoundly deaf children due to cochlear implantation. Some children with cochlear implants may need additional supports in educational settings.

Outcomes for School-Aged Children with Aural Atresia

This study compared the language, reading, classroom, and quality of life outcomes of primary school-aged children with aural atresia (AA) to matched controls. Participants included 10 children with AA (eight unilateral) and 10 children with typical hearing matched by chronological and mental age. All children with AA had been fitted with an amplification device. Outcome measures included standardized tests of language, reading, and functional communication questionnaires of children's classroom performance and hearing quality of life. The children with AA recorded significantly reduced hearing quality of life. The two groups did not differ on any other measures. The present preliminary findings suggest that children with AA who receive early amplification have similar language, communication, reading, and classroom outcomes as their typically hearing peers. Despite these promising outcomes, however, the children's quality of life is significantly reduced. Further research is needed to further elucidate these findings.

Predictors of Reading Comprehension in Children With Cochlear Implants

Children with a profound hearing loss who have been implanted with cochlear implants (CI), vary in terms of their language and reading skills. Some of these children have strong language skills and are proficient readers whereas others struggle with language and both the decoding and comprehension aspects of reading. Reading comprehension is dependent on a number of skills where decoding, spoken language comprehension and receptive vocabulary have been found to be the strongest predictors of performance. Children with CI have generally been found to perform more poorly than typically hearing peers on most predictors of reading comprehension including word decoding, vocabulary and spoken language comprehension, as well as working memory. The purpose of the current study was to investigate the relationships between reading comprehension and a number of predictor variables in a sample of twenty-nine 11–12-year-old children with profound hearing loss, fitted with CI. We were particularly interested in the extent to which reading comprehension in children with CI at this age is dependent on decoding and receptive vocabulary. The predictor variables that we set out to study were word decoding, receptive vocabulary, phonological skills, and working memory. A second purpose was to explore the relationships between reading comprehension and demographic factors, i.e., parental education, speech perception and age of implantation. The results from these 29 children indicate that receptive vocabulary is the most influential predictor of reading comprehension in this group of children although phonological decoding is, of course, fundamental.

Semantic processing in children with cochlear implants: Evidence from event-related potentials

Introduction: Existing research has shown that children with significant hearing loss who use cochlear implants (CIs) perform worse than their hearing peers on behavioral measures of spoken language. The present study sought to examine how children with CIs process lexical-semantic incongruence, as indexed by electrophysiological evidence of the N400 effect. Method: Twelve children with CIs, aged between 6 and 9 years, participated in a spoken word-picture matching task while event-related potentials (ERPs) were recorded. To determine whether the N400 effect elicited in this group deviated from normal, independent samples t tests and analysis of variance (ANOVA) analyses were used to compare the results of children with CIs against those of a similarly aged typically hearing (TH) group (n = 30). Correlational analyses were also conducted within each group to gauge the degree to which the N400 effect related to behavioral measures of spoken language. Results: An N400 effect was elicited in both groups of CI and TH children. The amplitude and latency of the N400 effect did not differ significantly between groups. Despite the similarity in ERP responses, children with CIs scored significantly lower on behavioral measures of spoken word- and sentence-level comprehension. No significant correlations between ERP and behavioral measures were found, although there was a trending relationship between sentence-level spoken language comprehension and the TH group's N400 effect mean amplitude (p = .060). Conclusions: The results suggest that, at a neural level, children with CIs can process lexical-semantic incongruence, and that other underlying processes not measured by the N400 effect contribute to this population's spoken language difficulties.