Functional hearing quality in prelingually deaf school-age children and adolescents with cochlear implants.

OBJECTIVE: This study investigated differences in functional hearing quality between youth with cochlear implants (CIs) and normal hearing (NH) peers, as well as associations between functional hearing quality and audiological measures, speech perception, language and executive functioning (EF). DESIGN: Youth with CIs and NH peers completed measures of audiological functioning, speech perception, language and EF. Parents completed the Quality of Hearing Scale (QHS), a questionnaire measure of functional hearing quality. STUDY SAMPLE: Participants were 43 prelingually-deaf, early-implanted, long-term CI users and 43 NH peers aged 7-17 years. RESULTS: Compared to NH peers, youth with CIs showed poorer functional hearing quality on the QHS Speech, Localization, and Sounds subscales and more hearing effort on the QHS Effort subscale. QHS scores did not correlate significantly with audiological/hearing history measures but were significantly correlated with most speech perception, language and EF scores in the CI sample. In the NH sample, QHS scores were uncorrelated with speech perception and language and were inconsistently correlated with EF. CONCLUSIONS: The QHS is a valid measure of functional hearing quality that is distinct from office-based audiometric or hearing history measures. Functional hearing outcomes are associated with speech-language and EF outcomes in CI users.

Verbal learning and memory in prelingually deaf children with cochlear implants.

OBJECTIVE: Deaf children with cochlear implants (CIs) show poorer verbal working memory compared to normal-hearing (NH) peers, but little is known about their verbal learning and memory (VLM) processes involving multi-trial free recall. DESIGN: Children with CIs were compared to NH peers using the California Verbal Learning Test for Children (CVLT-C). STUDY SAMPLE: Participants were 21 deaf (before age 6 months) children (6-16 years old) implanted prior to age 3 years, and 21 age-IQ matched NH peers. RESULTS: Results revealed no differences between groups in number of words recalled. However, CI users showed a pattern of increasing use of serial clustering strategies across learning trials, whereas NH peers decreased their use of serial clustering strategies. In the CI sample (but not in the NH sample), verbal working memory test scores were related to resistance to the build-up of proactive interference, and sentence recognition was associated with performance on the first exposure to the word list and to the use of recency recall strategies. CONCLUSIONS: Children with CIs showed robust evidence of VLM comparable to NH peers. However, their VLM processing (especially recency and proactive interference) was related to speech perception outcomes and verbal WM in different ways from NH peers.

Concept formation skills in long-term cochlear implant users.

This study investigated if a period of auditory sensory deprivation followed by degraded auditory input and related language delays affects visual concept formation skills in long-term prelingually deaf cochlear implant (CI) users. We also examined if concept formation skills are mediated or moderated by other neurocognitive domains (i.e., language, working memory, and executive control). Relative to normally hearing (NH) peers, CI users displayed significantly poorer performance in several specific areas of concept formation, especially when multiple comparisons and relational concepts were components of the task. Differences in concept formation between CI users and NH peers were fully explained by differences in language and inhibition-concentration skills. Language skills were also found to be more strongly related to concept formation in CI users than in NH peers. The present findings suggest that complex relational concepts may be adversely affected by a period of early prelingual deafness followed by access to underspecified and degraded sound patterns and spoken language transmitted by a CI. Investigating a unique clinical population such as early-implanted prelingually deaf children with CIs can provide new insights into foundational brain-behavior relations and developmental processes.

Speed of Information Processing and Verbal Working Memory in Children and Adolescents With Cochlear Implants.

BACKGROUND: Verbal working memory delays are found in many deaf children with cochlear implants compared with normal-hearing peers, but the factors contributing to these delays are not well understood. This study investigated differences between cochlear implant users and normal-hearing peers in memory scanning speed during a challenging verbal working memory task. To better understand variability in verbal working memory capacity within each sample, associations between memory scanning speed, speech recognition, and language were also investigated. METHODS: Twenty-five prelingually deaf, early implanted children (age, 8-17 yr) with cochlear implants and 25 normal-hearing peers completed the Wechsler Intelligence Scale for Children, Fifth Edition, Letter-Number Sequencing (LNS) working memory task. Timing measures were made for response latency and average pause duration between letters/numbers recalled during the task. Participants also completed measures of speech recognition, vocabulary, and language comprehension. RESULTS: Children with cochlear implants had longer pause durations than normal-hearing peers during three-span LNS sequences, but the groups did not differ in response latencies or in pause durations during two-span LNS sequences. In the sample of cochlear implant users, poorer speech recognition was correlated with longer pause durations during two-span sequences, whereas poorer vocabulary and weaker language comprehension were correlated with longer response latencies during two-span sequences. Response latencies and pause durations were unrelated to language in the normal-hearing sample. CONCLUSION: Children with cochlear implants have slower verbal working memory scanning speed than children with normal hearing. More robust phonological-lexical representations of language in memory may facilitate faster memory scanning speed and better working memory in cochlear implant users.

Verbal Fluency in Prelingually Deaf, Early Implanted Children and Adolescents With Cochlear Implants.

PURPOSE: Verbal fluency tasks assess the ability to quickly and efficiently retrieve words from the mental lexicon by requiring subjects to rapidly generate words within a phonological or semantic category. This study investigated differences between cochlear implant users and normal-hearing peers in the clustering and time course of word retrieval during phonological and semantic verbal fluency tasks. METHOD: Twenty-eight children and adolescents (aged 9-17 years) with cochlear implants and 33 normal-hearing peers completed measures of verbal fluency, nonverbal intelligence, speech perception, and verbal short-term/working memory. Phonological and semantic verbal fluency tests were scored for total words generated, words generated in each 10-s interval of the 1-min task, latency to first word generated, number of word clusters, average cluster size, and number of word/cluster switches. RESULTS: Children and adolescents with cochlear implants generated fewer words than normal-hearing peers throughout the entire 60-s time interval of the phonological and semantic fluency tasks. Cochlear implant users also had slower start latency times and produced fewer clusters and switches than normal-hearing peers during the phonological fluency task. Speech perception and verbal working memory scores were more strongly associated with verbal fluency scores in children and adolescents with cochlear implants than in normal-hearing peers. CONCLUSIONS: Cochlear implant users show poorer phonological and semantic verbal fluency than normal-hearing peers, and their verbal fluency is significantly associated with speech perception and verbal working memory. These findings suggest deficits in fluent retrieval of phonological and semantic information from long-term lexical memory in cochlear implant users.

Remote Assessment of Verbal Memory in Youth With Cochlear Implants During the COVID-19 Pandemic.

Purpose Youth with cochlear implants (CIs) are at risk for delays in verbal short-term memory (STM)/working memory (WM), which adversely affect language, neurocognitive, and behavioral outcomes. Assessment of verbal STM/WM is critical for identifying and addressing these delays, but standard assessment procedures require face-to-face (FTF) administration. The purpose of this study was to determine the feasibility and validity of remote testing methods (teleassessment) of verbal STM/WM in youth with CIs as a method of addressing COVID-19-related restrictions on FTF test administration. Method Tests of verbal STM/WM for nonwords, digit spans, letter-number sequences, sentences, and stories were individually administered by speech-language pathologists over a teleassessment platform to 28 youth (aged 9-22 years) with CIs and 36 same-aged normal-hearing peers. Examiners, parents, and participants completed quality and satisfaction ratings with the teleassessment procedure. Teleassessment scores were compared to results of tests obtained at FTF visits an average of 1.6 years earlier. Results Quality and satisfaction ratings for teleassessment were high and in almost all cases did not differ between the CI and normal-hearing samples. Youth with CIs scored lower than normal-hearing peers on measures of verbal STM/WM, and scores for digit span and letter-number sequencing did not differbetween teleassessment and FTF methods. Correlations across teleassessment and FTF visits were strong for digit span, letter-number sequencing, and sentence memory, but were more modest for nonword repetition. Conclusion With some caveats, teleassessment of verbal STM/WM was feasible and valid for youth with CIs.

Verbal Working Memory Error Patterns and Speech-Language Outcomes in Youth With Cochlear Implants.

PURPOSE: Verbal working memory (VWM) delays are commonly found in prelingually deaf youth with cochlear implants (CIs), albeit with considerable interindividual variability. However, little is known about the neurocognitive information-processing mechanisms underlying these delays and how these mechanisms relate to spoken language outcomes. The goal of this study was to use error analysis of the letter-number sequencing (LNS) task to test the hypothesis that VWM delays in CI users are due, in part, to fragile, underspecified phonological representations in short-term memory. METHOD: Fifty-one CI users aged 7-22 years and 53 normal hearing (NH) peers completed a battery of speech, language, and neurocognitive tests. LNS raw scores and error profiles were compared between samples, and a hierarchical regression model was used to test for associations with measures of speech, language, and hearing. RESULTS: Youth with CIs scored lower on the LNS test than NH peers and committed a significantly higher number of errors involving phonological confusions (recalling an incorrect letter/digit in place of a phonologically similar one). More phonological errors were associated with poorer performance on measures of nonword repetition and following spoken directions but not with hearing quality. CONCLUSIONS: Study findings support the hypothesis that poorer VWM in deaf children with CIs is due, in part, to fragile, underspecified phonological representations in short-term/working memory, which underlie spoken language delays. Programs aimed at strengthening phonological representations may improve VWM and spoken language outcomes in CI users.

Language processing fluency and verbal working memory in prelingually deaf long-term cochlear implant users: A pilot study.

OBJECTIVE: Verbal working memory (WM) is more strongly correlated with spoken language skills in prelingually deaf, early-implanted cochlear implant (CI) users than in normal-hearing (NH) peers, suggesting that CI users access WM in order to support and compensate for their slower, more effortful spoken language processing. This pilot study tested the feasibility and validity of a dual-task method for establishing the causal role of WM in basic language processing (lexical access speed) in samples of 9 CI users (ages 8-26 years) and 9 NH peers. METHODS: Participants completed tests of lexical access speed (rapid automatized picture naming test and lexical decision test) under two administration conditions: a standard condition and a dual-task WM condition requiring participants to hold numerals in WM during completion of the lexical access speed tests. RESULTS: CI users showed more dual-task interference (decline in speed during the WM condition compared to the standard condition) than NH peers, indicating that their lexical access speed was more dependent on engagement of WM resources. Furthermore, dual-task interference scores were significantly correlated with several measures of speed-based executive functioning (EF), consistent with the hypothesis that the dual-task method reflects the involvement of EF in language processing. CONCLUSION: These pilot study results support the feasibility and validity of the dual-task WM method for investigating the influence of WM in the basic language processing of CI users. Preliminary findings indicate that CI users are more dependent on the use of WM as a compensatory strategy during slow-effortful basic language processing than NH peers.