Effects of Early Auditory Deprivation on Working Memory and Reasoning Abilities in Verbal and Visuospatial Domains for Pediatric Cochlear Implant Recipients

Influence of Child-Level Factors and Lexical Characteristics on Vocabulary Knowledge of Children With Cochlear Implants and Hearing Aids

Recent studies indicate children who are deaf and hard of hearing who use cochlear implants or hearing aids know fewer spoken words than their peers with typical hearing, and often those vocabularies differ in composition. To date, however, the interaction of a child's auditory profile with the lexical characteristics of words he or she knows has been minimally explored. The purpose of the present study is to evaluate how audiological history, phonological memory, and overall vocabulary knowledge interact with growth in types of spoken words known by children who are deaf and hard of hearing compared to children with typical hearing. Children with cochlear implants (n = 36) and hearing aids (n = 39) were compared to children with typical hearing (n = 47) at ages 4 and 6. Children participated in measures of phonological memory and vocabulary knowledge, inclusive of an experimental measure with words of varying phonotactic probability and neighborhood density. Results indicate that children with hearing aids and with cochlear implants tend to know fewer words across all lexical conditions than children with typical hearing. For children with cochlear implants, overall vocabulary knowledge was the best predictor of a mis-matched probability and density condition, whereas it was the best predictor of matched condition for children with hearing aids. Children with cochlear implants and children with hearing aids, then, appear to have different underlying skills that interact with the lexical characteristics of words to support vocabulary growth.

Language and executive function in Mandarin-speaking deaf and hard-of-hearing children aged 3-5

The study aimed to explore spoken language and executive function (EF) characteristics in 3-5-year-old prelingually deaf and hard-of-hearing (DHH) children, and evaluate the impact of demographic variables and EF on spoken language skills. 48 DHH children and 48 typically developing children who use auditory-oral communication were recruited. All participants underwent EF tests, including auditory working memory (WM), inhibitory control, cognitive flexibility, and the EF performance reported by parents. Using Mandarin Clinical Evaluation of Language for Preschoolers (MCELP), vocabulary comprehension, sentence comprehension, vocabulary naming, sentence structure imitation, and story narration were evaluated only in the DHH group, and their results were compared with the typical developmental level provided by MCELP. Results showed that DHH children exhibit deficiencies in different spoken language domains and EF components. While the spoken language skills of DHH children tend to improve as they age, a growing proportion of individuals fail to reach the typical developmental level. The spoken language ability in DHH children was positively correlated with age and EFs, and negatively correlated with aided hearing threshold, while auditory WM could positively predict their spoken language performance.

Working Memory Deficits in School-Age Children With Cochlear Implants Are Primarily Explained by Deficits in the Processing of Auditory and Lexical Information

PURPOSE

Prelingual deaf children with cochlear implants show lower digit span test scores compared to normal-hearing peers, suggesting a working memory impairment. To pinpoint more precisely the subprocesses responsible for this impairment, we designed a sequence reproduction task with varying length (two to six stimuli), modality (auditory or visual), and compressibility (sequences with more or less regular patterns). Results on 22 school-age children with cochlear implants and 21 normal-hearing children revealed a deficit of children with cochlear implants only in the auditory modality. We observed no deficit in the visual modality and no deficit in the ability to detect and use regular patterns to improve memorization.

CONCLUSION

These results suggest that the working memory deficit of children with cochlear implants is explained by an impairment in the processing, encoding, and/or storage of the auditory and lexical information, as opposed to a global storage deficit or an inability to use compressibility strategies to improve memorization.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28216088.

Auditory working memory in noise in cochlear implant users: Insights from behavioural and neuronal measures

OBJECTIVE

We investigated auditory working-memory using behavioural measures and electroencephalography (EEG) in adult Cochlear Implant (CI) users with varying degrees of CI performance.

METHODS

24 adult CI listeners (age: M = 61.38, SD = 12.45) performed the Sternberg auditory-digit-in-working-memory task during which EEG, accuracy, and promptness were captured. Participants were presented with 2, 4, or 6 digits at Signal-to-Noise Ratios (SNR) of 0, +5 and +10dB. They had to identify a probe stimulus as present in the preceding sequence. ANOVA models were used to compare conditions.

RESULTS

ANOVA revealed that increasing memory load (ML) led to decreased task performance and CI performance interacted with ML and SNR. Centro-parietal alpha power increased during memory encoding but did not differ between conditions. Frontal alpha power was positively correlated with accuracy in conditions most affected by SNR (r = 0.57, r = 0.52) and theta power in conditions most affected by ML (r = 0.55, r = 0.57).

CONCLUSIONS

While parietal alpha power is modulated by the task, it is frontal alpha that relates quantitatively to sensory aspects of processing (noise) and frontal theta to memory load in this group of CI listeners.

SIGNIFICANCE

These results suggest that alpha and theta show distinct relationships to behaviour, providing additional insight into neurocognitive (auditory working-memory) processes in CI users.

Cross-modal digit span and vocabulary proficiency in deaf or hard-of-hearing children

This study aims to examine the relationship between vocabulary proficiency and short-term memory capacity in deaf or hard-of-hearing (DHH) children. We test the hypothesis that the relationship between vocabulary skills and digit span performance could be strengthened when the digit span task encompasses cross-modal integration processes. A group of DHH children performed two types of auditory digit span tasks. Furthermore, they participated in a standardized vocabulary proficiency test, comprising two subtests: Receptive Vocabulary and Expressive Vocabulary. The verbal digit span served as a significant predictor of Expressive Vocabulary among the DHH children. Simultaneously, the auditory-pointing digit span accounted for a substantial portion of performance variation in both Receptive and Expressive Vocabulary. After considering the impact of the duration of auditory-verbal intervention through regression models, likelihood ratio tests demonstrated that the auditory-pointing digit span persisted as a significant determinant of both receptive and expressive vocabulary skills. A positive influence of the intervention was also confirmed by the present results. This study provides evidence that memory span and the ability to integrate cross-modal information could serve as significant cognitive correlates of vocabulary proficiency in DHH children.

Language, cognitive, and speech in noise perception abilities of children with cochlear ımplants: a comparative analysis by implantation period and bilateral versus unilateral cochlear implants

PURPOSE

The purpose of this study was to compare the language, cognitive, and speech in noise (SiN) perception abilities of children with cochlear implants (CIs) to those of their peers with NH by grouping them according to their implantation period (12-18 months/19-24 months) and unilateral/bilateral CI use.

METHODS

The sample comprised 50 children with cochlear implants (CIs) and 20 children with normal hearing (NH), ages 6-9 years. Children's language, cognitive, and speech in noise (SiN) perception skills were assessed.

RESULTS

Children with CIs between 12 and 18 months and 19 and 24 months performed more poorly than children with NH on language, verbal memory (VM), verbal-short-term memory (V-STM), verbal working memory (V-WM), rapid naming, and speech in noise (SiN) perception abilities measures (p < 0.001). In addition, children with CIs between 19 and 24 months performed worse on rapid naming and V-WM tasks than children with CIs between 12 and 18 months (p < 0.017). Children with unilateral and bilateral CI performed more poorly than children with NH on language, VM, V-STM, V-WM, rapid naming, and SiN perception abilities assessments (p < 0.001). Additionally children with unilateral CI users performed poorly than children with bilateral CI users on SiN perception (p < 0.017).

CONCLUSIONS

In children with congenital hearing loss (CHL), cochlear implantation between 12 and 18 months or sequential bilateral implantation is not sufficient for these children to perform like their NH peers in language, cognitive, and SiN perception abilities. In addition, intervention approaches should focus not only on increasing language skills, but also on cognitive abilities.

How Hearing Loss and Cochlear Implantation Affect Verbal Working Memory: Evidence From Adolescents

PURPOSE

Verbal working memory is poorer for children with hearing loss than for peers with normal hearing (NH), even with cochlear implantation and early intervention. Poor verbal working memory can affect academic performance, especially in higher grades, making this deficit a significant problem. This study examined the stability of verbal working memory across middle childhood, tested working memory in adolescents with NH or cochlear implants (CIs), explored whether signal enhancement can improve verbal working memory, and tested two hypotheses proposed to explain the poor verbal working memory of children with hearing loss: (a) Diminished auditory experience directly affects executive functions, including working memory; (b) degraded auditory inputs inhibit children's abilities to recover the phonological structure needed for encoding verbal material into storage.

DESIGN

Fourteen-year-olds served as subjects: 55 with NH; 52 with CIs. Immediate serial recall tasks were used to assess working memory. Stimuli consisted of nonverbal, spatial stimuli and four kinds of verbal, acoustic stimuli: nonrhyming and rhyming words, and nonrhyming words with two kinds of signal enhancement: audiovisual and indexical. Analyses examined (a) stability of verbal working memory across middle childhood, (b) differences in verbal and nonverbal working memory, (c) effects of signal enhancement on recall, (d) phonological processing abilities, and (e) source of the diminished verbal working memory in adolescents with cochlear implants.

RESULTS

Verbal working memory remained stable across middle childhood. Adolescents across groups performed similarly for nonverbal stimuli, but those with CIs displayed poorer recall accuracy for verbal stimuli; signal enhancement did not improve recall. Poor phonological sensitivity largely accounted for the group effect.

CONCLUSIONS

The central executive for working memory is not affected by hearing loss or cochlear implantation. Instead, the phonological deficit faced by adolescents with CIs denigrates the representation in storage and augmenting the signal does not help.

An Evaluation of Language Development and Working Memory in Children with Hearing Loss

BACKGROUND

 Children with hearing loss (HL) have difficulty in performing the complex functions of language, especially in noisy environments. Cognitive processes such as working memory and short-term memory are effective on individual differences in language skills in children with HL.

PURPOSE

 The present study aimed to evaluate the vocabulary and syntax skills in language development areas and working memory of children with HL and to compare these results with those of their peers with normal hearing (NH).

RESEARCH DESIGN

 In this study, a causal-comparative research model was used to measure vocabulary and syntax skills, which are among the working memory and language development skills of children with NH and those with HL.

STUDY SAMPLE

 A total of 88 children, 44 children with HL aged 60 to 107 (months) and age- and gender-matched 44 children with NH, were included in the study.

INTERVENTION

 Evaluation was made in two sessions of 20 minutes for each participant.

DATA COLLECTION AND ANALYSIS

 The language development and working memory of 44 children with HL and 44 children with NH were evaluated and the two groups were compared with each other. The Working Memory Scale (WMS) was used to evaluate the working memory of the participants and three subtests (vocabulary, sentence repetition, and sentence comprehension) of the Test of Language Development-Primary Fourth Edition: Turkish Version (TOLD-P:4) were used to evaluate language development. SPSS 23.0 program was used in the analysis of the data.

RESULTS

 Children with HL obtained lower scores than their peers with NH in all three TOLD-P subtests. Children with HL obtained significantly lower scores in WMS verbal memory and general WMS scores compared with NH children. A positive correlation was found between WMS Verbal Memory Scores and TOLD-P sentence comprehension and sentence repetition scores. WMS Visual Memory Scores predicted the group with HL and all TOLD-P scores and Verbal Memory Scores predicted the group with NH.

CONCLUSION

 Working memory skills are the predictor of language comprehension, reasoning, learning, literacy skills, and language development. Thus, including working memory skills as well as language skills in the education programs of children with HL contributes to the children's development.

Working Memory, Attention Skills, and Language Proficiency in Children with Unilateral and Bilateral Cochlear Implants

BACKGROUND

 Previous studies observed that children with cochlear implants (CIs) have poor language, working memory, and attention skills. The ability to perform cognitive tasks, such as attention and memory, plays a crucial role in the academic achievement and everyday life of children with hearing impairment.

PURPOSE

 This study aimed to evaluate and compare the effects of age at the time of implantation and bilateral hearing on cognitive skills, such as language development, working memory, and selective attention, among children with CIs.

RESEARCH DESIGN

 Language skills were assessed using the Test of Language Development-Primary: Fourth Edition (TOLD-P:4), working memory using the Visual-Aural Digit Span Test-Revised Form (VADS-R), and selective attention skills using the Stroop Test TBAG Form.

STUDY SAMPLE

 A total of 58 participants, comprised of 21 children with early unilateral CIs (before 2 years), 18 children with late unilateral CIs (after 2 years), and 19 children with bilateral CIs, between the ages of 6 and 9 years, were included in the study.

DATA COLLECTION AND ANALYSIS

 According to the age at the time of implantation and whether or not the participant was unilaterally or bilaterally implanted, the mean scores, percentage values, and resultant scores of the participants were calculated using the Mann-Whitney U test. The number of repeated backward digit spans for the VADS-R test, completion times, number of errors and corrections for the Stroop test, raw scores, scaled scores corresponding to raw scores at the relevant age, descriptive terms for the TOLD-P:4 test, and within-group comparisons for all tests were examined.

RESULTS

 There were significant differences in language, working memory, and attention skills between individuals with early and late unilateral cochlear implantation, whereas there were no significant differences in many subtests between individuals with early unilateral and bilateral cochlear implantation.

CONCLUSION

 These findings demonstrate the importance of early cochlear implantation and bilateral hearing on the development of cognitive processes, such as language development, selective attention, and memory skills, which are important factors that may contribute to children's academic performance and overall success.

Effects of the BalanCI on Working Memory and Balance in Children and Young Adults With Cochleovestibular Dysfunction

OBJECTIVES

This study aimed to: (1) determine the interaction between cognitive load and balance in children and young adults with bilateral cochleovestibular dysfunction who use bilateral cochlear implants (CIs) and (2) determine the effect of an auditory balance prosthesis (the BalanCI) on this interaction. Many (20 to 70%) children with sensorineural hearing loss experience some degree of vestibular loss, leading to poorer balance. Poor balance could have effects on cognitive resource allocation which might be alleviated by the BalanCI as it translates head-referenced cues into electrical pulses delivered through the CI. It is hypothesized that children and young adults with cochleovestibular dysfunction will demonstrate greater dual-task costs than typically-developing children during dual balance-cognition tasks, and that BalanCI use will improve performance on these tasks.

DESIGN

Study participants were 15 typically-developing children (control group: mean age ± SD = 13.6 ± 2.75 years, 6 females) and 10 children and young adults who use bilateral CIs and have vestibular dysfunction (CI-V group: mean age ± SD=20.6 ± 5.36 years, 7 females). Participants completed two working memory tasks (backward auditory verbal digit span task and backward visuospatial dot matrix task) during three balance conditions: seated, standing in tandem stance with the BalanCI off, and standing in tandem stance with the BalanCI on. Working memory performance was quantified as total number of correct trials achieved. Postural stability was quantified as translational and rotational path length of motion capture markers worn on the head, upper body, pelvis, and feet, normalized by trial time.

RESULTS

Relative to the control group, children and young adults in the CI-V group exhibited poorer overall working memory across all balance conditions ( p = 0.03), poorer translational postural stability (larger translational path length) during both verbal and visuospatial working memory tasks ( p < 0.001), and poorer rotational stability (larger rotational path length) during the verbal working memory task ( p = 0.026). The CI-V group also exhibited poorer translational ( p = 0.004) and rotational ( p < 0.001) postural stability during the backward verbal digit span task than backward visuospatial dot matrix task; BalanCI use reduced this stability difference between verbal and visuospatial working memory tasks for translational stability overall ( p > 0.9), as well as for rotational stability during the maximum working memory span (highest load) participants achieved in each task ( p = 0.91).

CONCLUSIONS

Balance and working memory were impaired in the CI-V group compared with the control group. The BalanCI offered subtle improvements in stability in the CI-V group during a backward verbal working memory task, without producing a negative effect on working memory outcomes. This study supports the feasibility of the BalanCI as a balance prosthesis for individuals with cochleovestibular impairments.

Neurocognitive function in children with cochlear implants and hearing aids: a systematic review

Purpose

To systematically review the existing literature that examines the relationship between cognition, hearing, and language in children using cochlear implants and hearing aids.

Method

The review has been registered in Prospero (Registration: CRD 42020203974). The review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis and examined the scientific literature in VHL, MEDLINE, CINAHL, Scopus, WOS, and Embase. It included original observational studies in children using hearing aids and/or cochlear implants who underwent cognitive and auditory and/or language tests. Data were extracted from the studies and their level of evidence was graded with the Oxford Center for Evidence-Based Medicine: Levels of Evidence. Meta-analysis could not be performed due to data heterogeneity. Outcomes are described in narrative and tables synthesis.

Results

The systematic search and subsequent full-text evaluation identified 21 studies, conducted in 10 different countries. Altogether, their samples comprised 1,098 individuals, aged 0.16-12.6 years. The studies assessed the following cognitive domains: memory, nonverbal cognition, reasoning, attention, executive functions, language, perceptual-motor function, visuoconstructive ability, processing speed, and phonological processing/phonological memory. Children with hearing loss using cochlear implants and hearing aids scored significantly lower in many cognitive functions than normal hearing (NH) children. Neurocognitive functions were correlated with hearing and language outcomes.

Conclusion

Many cognitive tools were used to assess cognitive function in children with hearing devices. Results suggest that children with cochlear implants and hearing aids have cognitive deficits; these outcomes are mainly correlated with vocabulary. This study highlights the need to understand children's cognitive function and increase the knowledge of the relationship between cognition, language, and hearing in children using cochlear implants and hearing aids.

Evaluation of Verbal Working Memory and Phonemic Analysis Skills in Adolescents with Cochlear Implant

Introduction  Adolescents with cochlear implants may have difficulty developing language and memory abilities. Objective  The primary objectives of this study are (1) to evaluate the language skills and verbal working memory performance of early and late diagnosed-intervened cochlear implanted adolescents and (2) to investigate the relationship between the verbal working memory and phonemic analysis skills in adolescents with cochlear implant. Methods  This study included 72 participants with cochlear implant aged between 10 and 18 years. The participants were divided into two groups; those who had first hearing aid at the age of 6 months at the latest and had a first cochlear implant in at least one ear at the latest at 24 months were included in the early group, all the others were in the late group. The phonemic analysis test, a subtest of the test of language development: Primary, 4th edition (TOLD: P-4) - Turkish version, was used to assess language-based abilities, and the meaningless word repetition (MWR) test was utilized to assess verbal working memory. Results  The adolescents with cochlear implants who received early diagnosis and intervention performed statistically significantly better in phonemic analysis scores and verbal working memory tests ( p  < 0.001). A statistically significant relationship was found between phonemic analysis and verbal working memory skills (Pearson, r = 0.567 and r = 0.659, p  < 0.001). Conclusions  Rehabilitation of phonological skills can contribute to the development of verbal working memory in adolescents with cochlear implants. There is a need for further studies on this issue with more detailed tests.

Multidisciplinary Cognitive Function Assessment of Good versus Poor Performance in Children with Cochlear Implants: An Observational Cross-Sectional Study

Introduction  Despite the developing technology of cochlear implants (CIs), implanted prelingual hearing-impaired children exhibit variable speech processing outcomes. When these children match in personal and implant-related criteria, the CI outcome variability could be related to higher-order cognitive impairment. Objectives  To evaluate different domains of cognitive function in good versus poor CI performers using a multidisciplinary approach and to find the relationship between these functions and different levels of speech processing. Methods  This observational, cross-sectional study used the word recognition score (WRS) test to categorize 40 children with CIs into 20 good (WRS/65%) and 20 poor performers (WRS < 65%). All participants were examined for speech processing at different levels (auditory processing and spoken language) and cognitive functioning using (1) verbal tests (verbal component of Stanford-Binet intelligence [SBIS], auditory memory, auditory vigilance, and P300); and (2) performance tasks (performance components of SBIS, and trail making test). Results  The outcomes of speech processing at different functional levels and both domains of cognitive function were analyzed and correlated. Speech processing was impaired significantly in poor CI performers. This group also showed a significant cognitive function deficit, in which the verbal abilities were more affected (in 93.5%) than in the good performers (in 69.5%). Moreover, cognitive function revealed a significant correlation and predictive effect on the CI speech outcomes. Conclusion  Cognitive function impairment represented an important factor that underlies the variable speech proficiency in cochlear-implanted children. A multidisciplinary evaluation of cognitive function would provide a comprehensive overview to improve training strategies.

Language Intervention Instead of Speech Intervention for Children With Cochlear Implants

Cochlear implants are a standard rehabilitation option for children with severe hearing loss or deafness, allowing access to speech sounds necessary for the development of spoken language. However, the speech-language outcomes of pediatric cochlear implant users vary widely and are not directly or exclusively linked to technology but to combinations of individual audiological, personal, technical, and habilitational factors. These combinations may not favor spoken language development, which may further be linked to the issue of prior insistence on spoken language learning and associated with a high risk of language deprivation. Here, we discuss the outcomes of cochlear implantation from a habilitative perspective and lay down the efforts and resources necessary for the development of communication competence after cochlear implantation rather than the achievement of specific hearing, language, or speech skills that have limited socioemotional and educational contributions and do not guarantee an independent or productive life.

Dichotic listening deficits in children with hearing loss

PURPOSE

This correlational study compared dichotic listening among children with significant hearing loss to typically developing children and children clinically assessed for auditory processing disorder.

METHOD

Recorded versions of two dichotic tests were delivered under earphones or in the sound field for children using amplification. Individual ear scores and interaural asymmetry were compared to normative data. Matched deficit patterns from both tests were identified, ranked for severity of deficit, and compared across groups. Relationships between dichotic scores and factors related to amplification were investigated in the children with hearing loss.

RESULTS

Dichotic scores were significantly poorer among children with hearing loss without the large interaural asymmetries seen in children assessed clinically for auditory processing problems. Device type and age of implantation had no effect on scores; non-dominant ear scores on the digits test were significantly correlated to age of device use in the left ear and duration of device use in the right ear. Non-dominant ear scores with digits were also significantly correlated with bilateral word recognition.

CONCLUSIONS

Poor dichotic perception in children with significant hearing losses may be related to the use of recorded test materials, immature skills in attention and working memory, or other factors that contribute to development of vocabulary and language. These weaknesses may interfere with successful mainstream educational placement in these children. Assessment of dichotic performance in this population could lead to deficit-specific interventions that may improve outcomes and enhance educational opportunities for children with hearing loss.

Arabic phoneme-grapheme correspondence by non-native, deaf children with cochlear implants and normal hearing children

OBJECTIVE

This study aimed to compare the error patterns of Arabic phoneme-grapheme correspondence by a group of Malay children with cochlear implants (CIs) and normal hearing (NH) and the effects of the visual graphical features of Arabic graphemes (no-dot, single-dot, and multiple-dots) on the phoneme-grapheme correspondence.

METHODS

Participants were matched for hearing age (Mean, M = 7 ± 1.03 years) and duration of exposure to Arabic sounds (M = 2.7 ± 1.2 years). All 28 Arabic phonemes were presented through a loudspeaker and participants pointed to the graphemes associated with the presented phonemes.

RESULTS

A total of 336 and 616 tokens were collected for six children with CI and 11 NH children for each task, i.e., phonemes repetition and phoneme-grapheme correspondence. Both groups found it easier to repeat phonemes than the phoneme-grapheme correspondence. The children with CIs showed more confusion ([ظ, ز, ذ, ض, خ, ب, ه, س, ع, & ث] >10% correct scores) in phoneme-grapheme correspondence than the NH children ([ظ:14%] and [ث: 27%]). There was a significant interaction (p = 0.001) among the three visual graphical features and hearing status (CI and NH).

CONCLUSION

Our results infer that non-native Malay children with CIs and NH use different strategies to process the Arabic graphemes' visual features for phoneme-grapheme correspondence.

Amount of Hearing Aid Use Impacts Neural Oscillatory Dynamics Underlying Verbal Working Memory Processing for Children With Hearing Loss

OBJECTIVES

Children with hearing loss (CHL) may exhibit spoken language delays and may also experience deficits in other cognitive domains including working memory. Consistent hearing aid use (i.e., more than 10 hours per day) ameliorates these language delays; however, the impact of hearing aid intervention on the neural dynamics serving working memory remains unknown. The objective of this study was to examine the association between the amount of hearing aid use and neural oscillatory activity during verbal working memory processing in children with mild-to-severe hearing loss.

DESIGN

Twenty-three CHL between 8 and 15 years-old performed a letter-based Sternberg working memory task during magnetoencephalography (MEG). Guardians also completed a questionnaire describing the participants' daily hearing aid use. Each participant's MEG data was coregistered to their structural MRI, epoched, and transformed into the time-frequency domain using complex demodulation. Significant oscillatory responses corresponding to working memory encoding and maintenance were independently imaged using beamforming. Finally, these whole-brain source images were correlated with the total number of hours of weekly hearing aid use, controlling for degree of hearing loss.

RESULTS

During the encoding period, hearing aid use negatively correlated with alpha-beta oscillatory activity in the bilateral occipital cortices and right precentral gyrus. In the occipital cortices, this relationship suggested that with greater hearing aid use, there was a larger suppression of occipital activity (i.e., more negative relative to baseline). In the precentral gyrus, greater hearing aid use was related to less synchronous activity (i.e., less positive relative to baseline). During the maintenance period, hearing aid use significantly correlated with alpha activity in the right prefrontal cortex, such that with greater hearing aid use, there was less right prefrontal maintenance-related activity (i.e., less positive relative to baseline).

CONCLUSIONS

This study is the first to investigate the impact of hearing aid use on the neural dynamics that underlie working memory function. These data show robust relationships between the amount of hearing aid use and phase-specific neural patterns during working memory encoding and maintenance after controlling for degree of hearing loss. Furthermore, our data demonstrate that wearing hearing aids for more than ~8.5 hours/day may serve to normalize these neural patterns. This study also demonstrates the potential for neuroimaging to help determine the locus of variability in outcomes in CHL.

Lexical Competition Without Phonology: Masked Orthographic Neighbor Priming With Deaf Readers

Skilled reading is thought to rely on well-specified lexical representations that compete during visual word recognition. The establishment of these lexical representations is assumed to be driven by phonology. To test the role of phonology, we examined the prime lexicality effect (PLE), the index of lexical competition in signing deaf (N = 28) and hearing (N = 28) adult readers of Hungarian matched in age and education. We found no PLE for deaf readers even when reading skills were controlled for. Surprisingly, the hearing controls also showed reduced PLE; however, the effect was modulated by reading skill. More skilled hearing readers showed PLE, while more skilled deaf readers did not. These results suggest that phonology contributes to lexical competition; however, high-quality lexical representations are not necessarily built through phonology in deaf readers.

Variation in Auditory Experience Affects Language and Executive Function Skills in Children Who Are Hard of Hearing

OBJECTIVE

Children who are hard of hearing (CHH) experience delays in spoken language and executive function, but the mechanisms for these deficits remain unresolved. Differences in auditory experience and language skills have been examined as contributing factors to deficits in executive function, primarily with children who are deaf and children with cochlear implants. The theoretical model of cumulative auditory experience quantifies auditory dosage as how much speech is audible and how often children wear their hearing aids. CHH with higher auditory dosage have better language outcomes than peers with less auditory dosage. However, the effects of auditory experience on executive function have not been studied in CHH. The goal of this study was to examine the influences of auditory experience and language skills on the development of executive function in CHH.

DESIGN

We collected measures of aided speech audibility, hearing aid use, executive function, and receptive vocabulary in 177 CHH and 86 children with typical hearing who were 5- to 10 years old and matched for socioeconomic status and nonverbal intelligence. Auditory dosage was calculated by combining each child's average hours of hearing aid use with their audibility for speech to create a variable that quantifies individual differences in auditory access.

RESULTS

CHH had lower receptive vocabulary and deficits in executive function related to working memory and selective attention compared to peers with typical hearing. CHH with greater auditory dosage had higher receptive vocabulary than CHH with lower auditory dosage. Better receptive vocabulary was associated with better scores on executive function measures related to working memory and attention. Auditory dosage was also directly associated with measures of verbal working memory.

CONCLUSIONS

CHH have deficits in language and some, but not all, areas of executive function related to working memory and attention. Auditory dosage was associated with language abilities and verbal working memory. Language was associated with individual differences in executive function skills related to attention and working memory. These results provide support for systems theories regarding the development of executive function in CHH. Interventions that improve auditory access and language may be effective for improving executive function related to working memory and attention in CHH.

Executive Functions and Deafness: Results in a Group of Cochlear Implanted Children

Objects: This study aimed to evaluate the Executive Function (EF) domains in a group of profoundly deaf children treated with cochlear implant (CI) in comparison to normal hearing (NH) children. The secondary aim was to evaluate the influence exerted by the age at cochlear implant activation on EFs. Materials and Methods: 32 children were enrolled into two groups: group A of 17 CI users with a mean age of 8.78 years and group B of 15 NH subjects with a mean age of 7.99 years (SD + 2.3). All subjects were tested using the following tests: the subtests for working memory of the neuropsychological evaluation battery for the developmental age (Batteria di valutazione neuropsicologica per l’età evolutive), inhibition and control of the impulsive response—CAF, and the tower of London test. Results: No children with CIs scored within the normal range in the tests administered for the evaluation of EF domains. The same scores were significantly lower when compared with scores obtained by NH children. Children with younger age at CI activation showed better executive performances in planning, working memory (backward digit span), and cognitive flexibility (categorical fluency). Conclusion: The results of this study highlight that cochlear implantation plays a role in improving hearing and consequently influences the development of EFs in deaf children.

The impact of early auditory experience for the acquisition of morphosyntactic abilities and working memory

Difficulty in acquiring object clitics (OCs), and the omission of OCs more specifically, is used as a marker of developmental language disorder (DLD) in children learning French. Research also suggests that OCs are a complex morphosyntactic property of French and, as such, they could be particularly taxing for working memory (WM) resources. In light of previous research, it seems more likely that difficulties with OCs could be a marker for atypical early language acquisition. Children receiving a cochlear implant (CI) represent a case of delayed language exposure linked to a lack of early auditory exposure. Few studies have investigated the production of clitics in children with CIs. Studies suggest that children with CIs make significantly more clitic omissions on tasks of clitic production than typically-developing (TD) children. To our knowledge, no study has looked at clitic comprehension in children with CIs learning French or at the relationship between WM and performance on tasks of OCs in this population. The present study aimed at examining the production and comprehension of OCs, as well as the relationship between clitic omission and WM, in both typically-developing monolinguals children and CI recipients learning French. Children with CIs performed significantly lower than the control group on both comprehension and production tasks. Clitic omission was significantly related to WM, but only in the CI group suggesting a differential relationship between early auditory experience, WM, and language acquisition.

Variables influencing executive functioning in preschool hearing-impaired children implanted within 24 months of age: an observational cohort study

PURPOSE

Executive Functions (EFs) are fundamental to every aspect of life. The present study was implemented to evaluate factors influencing their development in a group of preschools orally educated profoundly deaf children of hearing parents, who received CI within 2 years of age.

METHODS

Twenty-five preschool CI children were tested using the Battery for Assessment of Executive Functions (BAFE) to assess their flexibility, inhibition, and non-verbal visuo-spatial working memory skills. The percentage of children performing in normal range was reported for each of the EF subtests. Mann-Whitney and Kruskal-Wallis were performed to assess differences between gender, listening mode, and degree of parents' education subgroups. The Spearman Rank Correlation Coefficient was calculated to investigate the relationship between EF scores of audiological and linguistic variables.

RESULTS

Percentages ranging from 76 to 92% of the children reached adequate EF scores at BAFE. Significant relations (p < 0.05) were found between EFs and early intervention, listening, and linguistic skills. Furthermore, CI children from families with higher education level performed better at the response shifting, inhibitory control, and attention flexibility tasks. Economic income correlated significantly with flexibility and inhibitory skills. Females performed better than males only in the attention flexibility task.

CONCLUSIONS

The present study is one of the first to focus attention on the development of EFs in preschool CI children, providing an initial understanding of the characteristics of EFs at the age when these skills emerge. Clinical practice must pay increasing attention to these aspects which are becoming the new emerging challenge of rehabilitation programs.

Systematic Review on Late Cochlear Implantation in Early-Deafened Adults and Adolescents: Predictors of Performance

OBJECTIVES

Early-deafened, late-implanted adolescents and adults constitute a unique group of cochlear implant (CI) users, showing a large variability in outcomes. The current systematic review aimed to determine which preimplantation factors are relevant in predicting postoperative outcomes in this patient group.

DESIGN

A systematic search for studies published between 2000 and September 2017 was performed in five electronic databases (PubMed, Embase, the Cochrane library, CINAHL, and PsycInfo). Prognostic studies that assessed the relation between patient-related factors and CI outcomes in early-deafened but late-implanted adolescent and adult CI users were included. Study quality was assessed with the Quality In Prognosis Studies (QUIPS) tool.

RESULTS

The systematic search and subsequent full-text evaluation identified 13 studies that had a clear prognostic study goal. Eight out of these 13 studies had a high risk of bias for at least one of the five QUIPS domains. Analysis of the outcomes identified that communication mode (in childhood), preoperative speech intelligibility, and preoperative speech recognition scores were significantly related to speech perception outcomes for this group of CI users. A number of additional factors considered worth for further investigation were also identified.

CONCLUSIONS

The analysis of the studies assessing the effect of a number of patient-related factors on outcome with CI in early-deafened adolescents and adults identified three potential prognostic factors and a number of additional factors to be incorporated in future research. More high-quality prognosis studies in the investigated patient population are still needed.

The Impact of Hearing Experience on Children's Use of Phonological and Semantic Information During Lexical Access

Purpose The purpose of this study was to examine the extent to which phonological competition and semantic priming influence lexical access in school-aged children with cochlear implants (CIs) and children with normal acoustic hearing. Method Participants included children who were 5-10 years of age with either normal hearing (n = 41) or bilateral severe to profound sensorineural hearing loss and used CIs (n = 13). All participants completed a two-alternative forced-choice task while eye gaze to visual images was recorded and quantified during a word recognition task. In this task, the target image was juxtaposed with a competitor image that was either a phonological onset competitor (i.e., shared the same initial consonant-vowel-consonant syllable as the target) or an unrelated distractor. Half of the trials were preceded by an image prime that was semantically related to the target image. Results Children with CIs showed evidence of phonological competition during real-time processing of speech. This effect, however, was less and occurred later in the time course of speech processing than what was observed in children with normal hearing. The presence of a semantically related visual prime reduced the effects of phonological competition in both groups of children but to a greater degree in children with CIs. Conclusions Children with CIs were able to process single words similarly to their counterparts with normal hearing. However, children with CIs appeared to have increased reliance on surrounding semantic information compared to their normal-hearing counterparts.

Effects of long-term unilateral cochlear implant use on large-scale network synchronization in adolescents

Unilateral cochlear implantation (CI) limits deafness-related changes in the auditory pathways but promotes abnormal cortical preference for the stimulated ear and leaves the opposite ear with little protection from auditory deprivation. In the present study, time-frequency analyses of event-related potentials elicited from stimuli presented to each ear were used to determine effects of unilateral CI use on cortical synchrony. CI-elicited activity in 34 adolescents (15.4±1.9 years of age) who had listened with unilateral CIs for most of their lives prior to bilateral implantation were compared to responses elicited by a 500Hz tone-burst in normal hearing peers. Phase-locking values between 4 and 60Hz were calculated for 171 pairs of 19-cephalic recording electrodes. Ear specific results were found in the normal hearing group: higher synchronization in low frequency bands (theta and alpha) from left ear stimulation in the right hemisphere and more high frequency activity (gamma band) from right ear stimulation in the left hemisphere. In the CI group, increased phase synchronization in the theta and beta frequencies with bursts of gamma activity were elicited by the experienced-right CI between frontal, temporal and parietal cortical regions in both hemispheres, consistent with increased recruitment of cortical areas involved in attention and higher-order processes, potentially to support unilateral listening. By contrast, activity was globally desynchronized in response to initial stimulation of the naïve-left ear, suggesting decoupling of these pathways from the cortical hearing network. These data reveal asymmetric auditory development promoted by unilateral CI use, resulting in an abnormally mature neural network.

Visual Sequence Repetition Learning is Not Impaired in Signing DHH Children

The auditory scaffolding hypothesis states that early experience with sound underpins the development of domain-general sequence processing abilities, supported by studies observing impaired sequence processing in deaf or hard-of-hearing (DHH) children. To test this hypothesis, we administered a sequence processing task to 77 DHH children who use American Sign Language (ASL) and 23 hearing monolingual children aged 7-12 years and found no performance difference between them after controlling for age and nonverbal intelligence. Additionally, neither spoken language comprehension scores nor hearing loss levels predicted sequence processing scores in the DHH group, whereas ASL comprehension scores did. Our results do not indicate sequence processing deficits in DHH children and do not support the auditory scaffolding hypothesis; instead, these findings suggest that factors related to experience with and/or proficiency in an accessible language during development may be more important determinants of sequence processing abilities.

Evaluation of phoneme recognition skills in pediatric auditory brainstem implant users

OBJECTIVES

This study aims to evaluate the relationship between phoneme recognition skills and language development skills in pediatric auditory brainstem implant (ABI) users. It further intends to identify the delays and problems that may occur in the phoneme recognition skills of children with ABI and shed light on rehabilitation programs.

METHODS

Our study included 20 children using ABI and another 20 using cochlear implants (CI). They were aged between 6 and 8 years 11 months. The participants exhibited homogenous demographic and audiological characteristics. The Turkish version of the Test of Language Development-Primary: Fourth Edition (TOLDP:4) was used to evaluate the language development skills, and the Turkish version of the Phoneme Recognition Test (PRT) was applied to assess the phoneme recognition skills.

RESULTS

There was a statistically significant difference (p < 0.05) in the PRT values as well as in the language development skills between the children with ABI and those with CI. It was observed that the values of the children with CI were significantly higher than those of children with ABI.

CONCLUSION

Although children with ABI were not able to match the skills of their peers with CI, their language development and communication skills improved. It is believed that this study will contribute to the literature by demonstrating that the use of ABI improves phoneme recognition skills in children who are not eligible for CI or who do not adequately benefit from CI.

The relationship between reasoning and language ability: comparing children with cochlear implants and children with typical hearing

PURPOSE

Language has been suggested to play a facilitating role for analogical reasoning tasks, especially for those with high complexity. This study aims to evaluate if differences in analogical reasoning ability between children with cochlear implants (CI) and children with typical hearing (TH) might be explained by differences in language ability.

METHODS

The analogical reasoning ability (verbal; non-verbal; complex non-verbal: high relational integration demand) of children with CI (N = 15, mean age = 6;7) was compared to two groups of children with TH: age and language matched (TH-A+L, N = 23, mean age = 6;5), and age matched (TH-A, N = 23, mean age = 6;5).

RESULTS

Children with CI were found to perform comparable to Group TH-A+L on non-verbal reasoning tasks but significantly more poorly on a verbal analogical reasoning task. Children with CI were found to perform significantly more poorly on both the non-verbal analogical reasoning task with high relational integration demand and on the verbal analogical reasoning task compared to Group TH-A. For the non-verbal analogical reasoning task with lower relational integration demand only a tendency for a difference between group CI and Group TH-A was found.

CONCLUSIONS

The results suggest that verbal strategies are influencing the performance on the non-verbal analogical reasoning tasks with a higher relational integration demand. The possible reasons for this are discussed. The verbal analogical reasoning task used in the current study partly measured lexical access. Differences between the children with CI and both groups of children with TH might therefore be explained by differences in expressive vocabulary skills.

The Relation Between Vocabulary Knowledge and Phonological Awareness in Children With Cochlear Implants

Purpose The purpose of this study was to evaluate the relation between lexical knowledge and phonological awareness performance of children with cochlear implants. Method Thirty children with cochlear implants (aged 5-7 years), 30 children with normal hearing matched for age, and 30 children with normal hearing matched for vocabulary size participated in the study. Children completed a vocabulary knowledge measure and three phonological awareness tasks with words that had high and low neighborhood density. Results Children with cochlear implants performed more poorly than their age-matched peers and similarly to their vocabulary-matched peers on phonological awareness tasks. When performance was analyzed according to the neighborhood density of the target word, children with cochlear implants and age-matched children performed better with high-density words. Across all groups, vocabulary size correlated significantly with phonological awareness performance. Conclusion Children with cochlear implants demonstrate delays in both vocabulary knowledge and phonological awareness performance, but children with cochlear implants appear to take advantage of lexical information similarly to their age-matched peers.

Speech-in-Noise Perception in Children With Cochlear Implants, Hearing Aids, Developmental Language Disorder and Typical Development: The Effects of Linguistic and Cognitive Abilities

Children with hearing loss, and those with language disorders, can have excellent speech recognition in quiet, but still experience unique challenges when listening to speech in noisy environments. However, little is known about how speech-in-noise (SiN) perception relates to individual differences in cognitive and linguistic abilities in these children. The present study used the Norwegian version of the Hearing in Noise Test (HINT) to investigate SiN perception in 175 children aged 5.5-12.9 years, including children with cochlear implants (CI, n = 64), hearing aids (HA, n = 37), developmental language disorder (DLD, n = 16) and typical development (TD, n = 58). Further, the study examined whether general language ability, verbal memory span, non-verbal IQ and speech perception of monosyllables and sentences in quiet were predictors of performance on the HINT. To allow comparisons across ages, scores derived from age-based norms were used for the HINT and the tests of language and cognition. There were significant differences in SiN perception between all the groups except between the HA and DLD groups, with the CI group requiring the highest signal-to-noise ratios (i.e., poorest performance) and the TD group requiring the lowest signal-to-noise ratios. For the full sample, language ability explained significant variance in HINT performance beyond speech perception in quiet. Follow-up analyses for the separate groups revealed that language ability was a significant predictor of HINT performance for children with CI, HA, and DLD, but not for children with TD. Memory span and IQ did not predict variance in SiN perception when language ability and speech perception in quiet were taken into account. The finding of a robust relation between SiN perception and general language skills in all three clinical groups call for further investigation into the mechanisms that underlie this association.

Preserving Inhibition during Developmental Hearing Loss Rescues Auditory Learning and Perception

Transient periods of childhood hearing loss can induce deficits in aural communication that persist long after auditory thresholds have returned to normal, reflecting long-lasting impairments to the auditory CNS. Here, we asked whether these behavioral deficits could be reversed by treating one of the central impairments: reduction of inhibitory strength. Male and female gerbils received bilateral earplugs to induce a mild, reversible hearing loss during the critical period of auditory cortex development. After earplug removal and the return of normal auditory thresholds, we trained and tested animals on an amplitude modulation detection task. Transient developmental hearing loss induced both learning and perceptual deficits, which were entirely corrected by treatment with a selective GABA reuptake inhibitor (SGRI). To explore the mechanistic basis for these behavioral findings, we recorded the amplitudes of GABA_A and GABA_B receptor-mediated IPSPs in auditory cortical and thalamic brain slices. In hearing loss-reared animals, cortical IPSP amplitudes were significantly reduced within a few days of hearing loss onset, and this reduction persisted into adulthood. SGRI treatment during the critical period prevented the hearing loss-induced reduction of IPSP amplitudes; but when administered after the critical period, it only restored GABA_B receptor-mediated IPSP amplitudes. These effects were driven, in part, by the ability of SGRI to upregulate α1 subunit-dependent GABA_A responses. Similarly, SGRI prevented the hearing loss-induced reduction of GABA_A and GABA_B IPSPs in the ventral nucleus of the medial geniculate body. Thus, by maintaining, or subsequently rescuing, GABAergic transmission in the central auditory thalamocortical pathway, some perceptual and cognitive deficits induced by developmental hearing loss can be prevented.SIGNIFICANCE STATEMENT Even a temporary period of childhood hearing loss can induce communication deficits that persist long after auditory thresholds return to normal. These deficits may arise from long-lasting central impairments, including the loss of synaptic inhibition. Here, we asked whether hearing loss-induced behavioral deficits could be reversed by reinstating normal inhibitory strength. Gerbils reared with transient hearing loss displayed both learning and perceptual deficits. However, when animals were treated with a selective GABA reuptake inhibitor during or after hearing loss, behavioral deficits were entirely corrected. This behavioral recovery was correlated with the return of normal thalamic and cortical inhibitory function. Thus, some perceptual and cognitive deficits induced by developmental hearing loss were prevented with a treatment that rescues a central synaptic property.