Article

Verbal Learning and Memory After Cochlear Implantation in Postlingually Deaf Adults: Some New Findings with the CVLT-II

December 2017
Ear and Hearing 39(4)

DOI:10.1097/AUD.0000000000000530

Authors:

David B Pisoni

Indiana University Bloomington

Arthur Broadstock

The Ohio State University

Taylor Wucinich

The Ohio State University

Natalie Safdar

The Ohio State University

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Objectives: Despite the importance of verbal learning and memory in speech and language processing, this domain of cognitive functioning has been virtually ignored in clinical studies of hearing loss and cochlear implants in both adults and children. In this article, we report the results of two studies that used a newly developed visually based version of the California Verbal Learning Test-Second Edition (CVLT-II), a well-known normed neuropsychological measure of verbal learning and memory. Design: The first study established the validity and feasibility of a computer-controlled visual version of the CVLT-II, which eliminates the effects of audibility of spoken stimuli, in groups of young normal-hearing and older normal-hearing (ONH) adults. A second study was then carried out using the visual CVLT-II format with a group of older postlingually deaf experienced cochlear implant (ECI) users (N = 25) and a group of ONH controls (N = 25) who were matched to ECI users for age, socioeconomic status, and nonverbal IQ. In addition to the visual CVLT-II, subjects provided data on demographics, hearing history, nonverbal IQ, reading fluency, vocabulary, and short-term memory span for visually presented digits. ECI participants were also tested for speech recognition in quiet. Results: The ECI and ONH groups did not differ on most measures of verbal learning and memory obtained with the visual CVLT-II, but deficits were identified in ECI participants that were related to recency recall, the buildup of proactive interference, and retrieval-induced forgetting. Within the ECI group, nonverbal fluid IQ, reading fluency, and resistance to the buildup of proactive interference from the CVLT-II consistently predicted better speech recognition outcomes. Conclusions: Results from this study suggest that several underlying foundational neurocognitive abilities are related to core speech perception outcomes after implantation in older adults. Implications of these findings for explaining individual differences and variability and predicting speech recognition outcomes after implantation are discussed.

Exploring neurocognitive factors and brain activation in adult cochlear implant recipients associated with speech perception outcomes—A scoping review

Article

Full-text available

Feb 2023

Background Cochlear implants (CIs) are considered an effective treatment for severe-to-profound sensorineural hearing loss. However, speech perception outcomes are highly variable among adult CI recipients. Top-down neurocognitive factors have been hypothesized to contribute to this variation that is currently only partly explained by biological and audiological factors. Studies investigating this, use varying methods and observe varying outcomes, and their relevance has yet to be evaluated in a review. Gathering and structuring this evidence in this scoping review provides a clear overview of where this research line currently stands, with the aim of guiding future research. Objective To understand to which extent different neurocognitive factors influence speech perception in adult CI users with a postlingual onset of hearing loss, by systematically reviewing the literature. Methods A systematic scoping review was performed according to the PRISMA guidelines. Studies investigating the influence of one or more neurocognitive factors on speech perception post-implantation were included. Word and sentence perception in quiet and noise were included as speech perception outcome metrics and six key neurocognitive domains, as defined by the DSM-5, were covered during the literature search (Protocol in open science registries: 10.17605/OSF.IO/Z3G7W of searches in June 2020, April 2022). Results From 5,668 retrieved articles, 54 articles were included and grouped into three categories using different measures to relate to speech perception outcomes: (1) Nineteen studies investigating brain activation, (2) Thirty-one investigating performance on cognitive tests, and (3) Eighteen investigating linguistic skills. Conclusion The use of cognitive functions, recruiting the frontal cortex, the use of visual cues, recruiting the occipital cortex, and the temporal cortex still available for language processing, are beneficial for adult CI users. Cognitive assessments indicate that performance on non-verbal intelligence tasks positively correlated with speech perception outcomes. Performance on auditory or visual working memory, learning, memory and vocabulary tasks were unrelated to speech perception outcomes and performance on the Stroop task not to word perception in quiet. However, there are still many uncertainties regarding the explanation of inconsistent results between papers and more comprehensive studies are needed e.g., including different assessment times, or combining neuroimaging and behavioral measures. Systematic review registration https://doi.org/10.17605/OSF.IO/Z3G7W .

Contribution of Verbal Learning & Memory and Spectro‐Temporal Discrimination to Speech Recognition in Cochlear Implant Users

Article

May 2022

Objectives: Existing cochlear implant (CI) outcomes research demonstrates a high degree of variability in device effectiveness among experienced CI users. Increasing evidence suggests that verbal learning and memory (VL&M) may have an influence on speech recognition with CIs. This study examined the relations in CI users between visual measures of VL&M and speech recognition in a series of models that also incorporated spectro-temporal discrimination. Predictions were that (1) speech recognition would be associated with VL&M abilities and (2) VL&M would contribute to speech recognition outcomes above and beyond spectro-temporal discrimination in multivariable models of speech recognition. Methods: This cross-sectional study included 30 adult postlingually deaf experienced CI users who completed a nonauditory visual version of the California Verbal Learning Test-Second Edition (v-CVLT-II) to assess VL&M, and the Spectral-Temporally Modulated Ripple Test (SMRT), an auditory measure of spectro-temporal processing. Participants also completed a battery of word and sentence recognition tasks. Results: CI users showed significant correlations between some v-CVLT-II measures (short-delay free- and cued-recall, retroactive interference, and "subjective" organizational recall strategies) and speech recognition measures. Performance on the SMRT was correlated with all speech recognition measures. Hierarchical multivariable linear regression analyses showed that SMRT performance accounted for a significant degree of speech recognition outcome variance. Moreover, for all speech recognition measures, VL&M scores contributed independently in addition to SMRT. Conclusion: Measures of spectro-temporal discrimination and VL&M were associated with speech recognition in CI users. After accounting for spectro-temporal discrimination, VL&M contributed independently to performance on measures of speech recognition for words and sentences produced by single and multiple talkers. Level of evidence: 3 Laryngoscope, 2022.

Verbal Learning and Memory in Early-Implanted, Prelingually Deaf Adolescent and Adult Cochlear Implant Users

Article

Full-text available

Mar 2019

Purpose The purpose of this study was to investigate the information-processing strategies of early-implanted, prelingually deaf cochlear implant (CI) users with the California Verbal Learning Test–Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000 ), a well-established normed measure of verbal learning and memory used in neuropsychological assessments of memory loss. Method Verbal learning and memory skills were compared in 20 older adolescent and young adult prelingually deaf long-term early-implanted CI users and their 24 normal hearing (NH) peers using the CVLT-II, a widely used multitrial free recall test of verbal learning and memory. Results On average, CI users recalled fewer words than their NH peers across the immediate, delayed, and cued recall trials of the CVLT-II but were comparable to their NH peers on yes/no recognition memory. CI users showed little evidence of semantic clustering of words during free recall but greater serial clustering compared to their NH peers, suggesting fundamental disturbances in automatic semantic activation of words from long-term memory. No differences were found in verbal memory between CI users and their NH peers on measures of retroactive interference and encoding/retrieval interactions. Performance on the 2nd word list of the CVLT-II (List B) and amount of semantic clustering of words during recall were correlated with sentence recognition in the CI group. Conclusion Study findings demonstrate significant differences in free recall performance and information-processing strategies that early-implanted, prelingually deaf CI users use to encode, organize, store, and retrieve spoken words in conventional verbal list learning paradigms, compared to their NH peers. Because verbal learning and memory are core foundational processes routinely used in daily functioning for a wide range of neurocognitive and language processing operations, these findings suggest potential domains for assessment and novel interventions to promote the development of optimal outcomes in prelingually deaf early-implanted long-term CI users.

Assessing Cognitive Abilities in High-Performing Cochlear Implant Users

Article

Full-text available

Jan 2019

Despite being considered one of the most successful neural prostheses, cochlear implants (CIs) provide recipients with a wide range of speech perception performance. While some CI users can understand speech in the absence of visual cues, other recipients exhibit more limited speech perception. Cognitive skills have been documented as a contributor to complex auditory processing, such as language understanding; however, there are no normative data for existing standardized clinical tests assessing cognitive abilities in CI users. Here, we assess the impact of modality of presentation (i.e., auditory-visual versus visual) for the administration of working memory tests in high-performing CI users in addition to measuring processing speed, cognitive efficiency and intelligence quotient (IQ). Second, we relate performance on these cognitive measures to clinical CI speech perception outcomes. Methods: Twenty one post-lingually deafened, high-performing, adult CI users [age range: 52–88 years; 3 unilateral CI, 13 bimodal (i.e., CI with contralateral hearing aid), 5 bilateral CI] with clinical speech perception scores (i.e., AzBio sentences in quiet for the first-ear CI) of ≥60% were recruited. A cognitive test battery assessing auditory-visual working memory (AVWM), visual working memory (VWM), processing speed, cognitive efficiency and IQ was administered, in addition to clinical measures of speech perception in quiet (i.e., AzBio sentences in quiet). AzBio sentences were assessed in two conditions: first-ear CI only, and best-aided everyday wearing condition. Subjects also provided self-reported measures of performance and benefit from their CI using standardized materials, including the Glasgow Benefit Inventory (GBI) and the Nijmegen Cochlear Implant questionnaire (NCIQ). Results: High-performing CI users demonstrated greater VWM than AVWM recall. VWM was positively related to AzBio scores when measured in the first-ear CI only. AVWM, processing speed, cognitive efficiency, and IQ did not relate to either measure of speech perception (i.e., first-ear CI or best-aided conditions). Subjects’ self-reported benefit as measured by the GBI predicted best-aided CI speech perception performance. Conclusion: In high-performing CI recipients, visual presentation of working memory tests may improve our assessment of cognitive function.

Three challenges for future research on cochlear implants

Article

Full-text available

Jan 2018

Cochlear implants (CIs) often work very well for many children and adults with profound sensorineural (SNHL) hearing loss. Unfortunately, while many CI patients display substantial benefits in recognizing speech and understanding spoken language following cochlear implantation, a large number of patients achieve poor outcomes. Understanding and explaining the reasons for poor outcomes following implantation is a very challenging research problem that has received little attention despite the pressing clinical significance. In this paper, we discuss three challenges for future research on CIs. First, we consider the issue of individual differences and variability in outcomes following implantation. At the present time, we still do not have a complete and satisfactory account of the causal underlying factors that are responsible for the enormous individual differences and variability in outcomes. Second, we discuss issues related to the lack of preimplant predictors of outcomes. Very little prospective research has been carried out on the development of preimplant predictors that can be used to reliably identify CI candidates who may be at high risk for a poor outcome following implantation. Other than conventional demographics and hearing history, there are no prognostic tools available to predict speech recognition outcomes after implantation. Finally, we discuss the third challenge — what to do with a CI-user who has a poor outcome. We suggest that new research efforts need to be devoted to studying this neglected clinical population in greater depth to find out why they are doing poorly with their CI and what novel interventions and treatments can be developed to improve their speech recognition outcomes. Using these three challenges as objectives for future research on CIs, we suggest that the field needs to adopt a new narrative grounded in theory and methods from Cognitive Hearing Science and information processing theory. Without knowing which specific biological and neurocognitive factors are responsible for individual differences or understanding the underlying sensory and neurocognitive basis for variability in performance, it is impossible to select a specific approach to habilitation after a deaf adult or child receives a CI. Deaf adults and children who are performing poorly with their CIs are not a homogeneous group and may differ in many different ways from each other, reflecting the dysfunction of multiple brain systems associated with both congenital and acquired deafness. Hearing loss is not only an ear issue, it is also a brain issue too reflecting close links between perception and action and brain, body and world working together as a functionally integrated information processing system to support robust speech recognition and spoken language processing after implantation.

Examining Delayed Recall in Cochlear Implant Users Using the Montreal Cognitive Assessment, California Verbal Learning Test, Third Edition, and Item Specific Deficit Approach: Preliminary Results

Article

Full-text available

Nov 2021

Purpose: Recent studies using the Montreal Cognitive Assessment (MoCA) suggest delayed recall is challenging for cochlear implant (CI) users. To better understand the underlying processes associated with delayed recall in CI users, we administered the MoCA and the California Verbal Learning Test, Third Edition (CVLT-3), which provides a more comprehensive assessment of delayed recall ability. Methods: The MoCA and CVLT-3 were administered to 18 high-performing CI users. For the CVLT-3, both the traditional scoring and a newer scoring method, the Item-Specific Deficit Approach (ISDA), were employed. Results: The original MoCA score and MoCA delayed recall subtest score did not relate to performance on any CVLT-3 measures regardless of scoring metric applied (i.e., traditional or ISDA). Encoding performance for both the CVLT-3 and ISDA were related. Consolidation, which is only distinctly defined by the ISDA, related to CVLT-3 cued delay recall performance but not free delay recall performance. Lastly, ISDA retrieval only related to CVLT-3 measures when modified. Conclusion: Performance on the MoCA and CVLT-3 in a high performing CI patient population were not related. We demonstrate that the ISDA can be successfully applied to CI users for the quantification and characterization of delayed recall ability; however, future work addressing lower performing CI users, and comparing to normal hearing controls is needed to determine the extent of potential translational applications. Our work also indicates that a modified ISDA retrieval score may be beneficial for evaluating CI users although additional work addressing the clinical relevance of this is still needed.

Comprehension of Morse Code Predicted by Item Recall From Short-Term Memory

Article

Sep 2021

Purpose Morse code as a form of communication became widely used for telegraphy, radio and maritime communication, and military operations, and remains popular with ham radio operators. Some skilled users of Morse code are able to comprehend a full sentence as they listen to it, while others must first transcribe the sentence into its written letter sequence. Morse thus provides an interesting opportunity to examine comprehension differences in the context of skilled acoustic perception. Measures of comprehension and short-term memory show a strong correlation across multiple forms of communication. This study tests whether this relationship holds for Morse and investigates its underlying basis. Our analyses examine Morse and speech immediate serial recall, focusing on established markers of echoic storage, phonological-articulatory coding, and lexical-semantic support. We show a relationship between Morse short-term memory and Morse comprehension that is not explained by Morse perceptual fluency. In addition, we find that poorer serial recall for Morse compared to speech is primarily due to poorer item memory for Morse, indicating differences in lexical-semantic support. Interestingly, individual differences in speech item memory are also predictive of individual differences in Morse comprehension. Conclusions We point to a psycholinguistic framework to account for these results, concluding that Morse functions like “reading for the ears” ( Maier et al., 2004 ) and that underlying differences in the integration of phonological and lexical-semantic knowledge impact both short-term memory and comprehension. The results provide insight into individual differences in the comprehension of degraded speech and strategies that build comprehension through listening experience. Supplemental Material https://doi.org/10.23641/asha.16451868

Factors Influencing Speech Perception in Adults With a Cochlear Implant

Article

Full-text available

Jan 2021

Objectives: The primary objective of this study is to identify the biographic, audiologic, and electrode position factors that influence speech perception performance in adult cochlear implant (CI) recipients implanted with a device from a single manufacturer. The secondary objective is to investigate the independent association of the type of electrode (precurved or straight) with speech perception. Design: In a cross-sectional study design, speech perception measures and ultrahigh-resolution computed tomography scans were performed in 129 experienced CI recipients with a postlingual onset of hearing loss. Data were collected between December 2016 and January 2018 in the Radboud University Medical Center, Nijmegen, the Netherlands. The participants received either a precurved electrode (N = 85) or a straight electrode (N = 44), all from the same manufacturer. The biographic variables evaluated were age at implantation, level of education, and years of hearing loss. The audiometric factors explored were preoperative and postoperative pure-tone average residual hearing and preoperative speech perception score. The electrode position factors analyzed, as measured from images obtained with the ultrahigh-resolution computed tomography scan, were the scalar location, angular insertion depth of the basal and apical electrode contacts, and the wrapping factor (i.e., electrode-to-modiolus distance), as well as the type of electrode used. These 11 variables were tested for their effect on three speech perception outcomes: consonant-vowel-consonant words in quiet tests at 50 dB SPL (CVC50) and 65 dB SPL (CVC65), and the digits-in-noise test. Results: A lower age at implantation was correlated with a higher CVC50 phoneme score in the straight electrode group. Other biographic variables did not correlate with speech perception. Furthermore, participants implanted with a precurved electrode and who had poor preoperative hearing thresholds performed better in all speech perception outcomes than the participants implanted with a straight electrode and relatively better preoperative hearing thresholds. After correcting for biographic factors, audiometric variables, and scalar location, we showed that the precurved electrode led to an 11.8 percentage points (95% confidence interval: 1.4-20.4%; p = 0.03) higher perception score for the CVC50 phonemes compared with the straight electrode. Furthermore, contrary to our initial expectations, the preservation of residual hearing with the straight electrode was poor, as the median preoperative and the postoperative residual hearing thresholds for the straight electrode were 88 and 122 dB, respectively. Conclusions: Cochlear implantation with a precurved electrode results in a significantly higher speech perception outcome, independent of biographic factors, audiometric factors, and scalar location.

Speech and language assessment in adult cochlear implant candidates and users

Article

Full-text available

Dec 2020

In the Czech literature there is a lack of information about speech and language assessment in adult cochlear implant (CI) candidates and users. The article presents the issue of adult cochlear implantation from a speech and language therapist perspective. The paper points out the current changes in the CI candidacy, which have opened the possibility to provide cochlear implantation to other types of patients, including bilateral implantation in adults. The aim of the article is to present an overview of diagnostic tools used abroad. Moreover, it provides the information about the current pre- and post-implantation possibilities in terms of speech and language evaluation in Czechia.

Visual and Auditory Verbal Memory in Older Adults: Comparing Postlingually Deaf Cochlear Implant Users to Normal Hearing Controls

Article

Nov 2020

Purpose. To test whether a group of older postlingually-deafened cochlear-implant users (OCI) use similar verbal memory strategies to those used by older normal-hearing (ONH) adults. Verbal memory functioning was assessed in the visual and auditory modalities separately, enabling us to eliminate possible modality-based biases. Method. Participants performed two separate visual and auditory verbal memory tasks. In each task, the visually or aurally presented study words were learned by vocal production (saying aloud) or by no-production (reading silently or listening), followed by a free-recall test. Twenty-seven older adults (> 60 years) participated (OCI = 13, ONH = 14), all of whom demonstrated intact cognitive abilities. All OCIs showed good open-set speech perception results in quiet. Results. Both ONHs and OCIs showed production benefits (higher recall rates for vocalized than non-vocalized words) in the visual and the auditory tasks. The ONHs showed similar production benefits in the visual and the auditory tasks. The OCIs demonstrated a smaller production effect in the auditory task. Conclusions. These results may indicate that different modality-specific memory strategies were used by the ONHs and the OCIs. The group-differences in memory performance suggest that even when deafness occurs after the completion of language acquisition, the reduced and distorted external auditory stimulation leads to a deterioration in the phonological representation of sounds. Possibly, this deterioration leads to a less efficient auditory long-term verbal memory.

Comprehensive auditory rehabilitation in adults receiving cochlear implants: A pilot study

Article

Full-text available

Sep 2020

Objective In the United States, most adults who receive cochlear implants (CIs) do not undergo a comprehensive auditory rehabilitation (CAR) approach, which may result in suboptimal outcomes. The objectives of this pilot study were to demonstrate that a CAR approach incorporating auditory training (AT) by a speech‐language pathologist (SLP) is feasible in adults receiving CIs and to explore whether this approach results in improved outcomes. Methods Twenty‐four postlingually deaf adult CI candidates were serially assigned to one of three groups: (a) a “CAR group” that received standard of care implantation, programming by an audiologist, an additional preoperative counseling session, and eight one‐hour AT sessions; (b) a “passive control” standard‐of‐care group; and (c) an “active control” group that also received the extra preoperative counseling session. Participants were tested preoperatively and 1, 3, and 6 months after CI using measures of word and sentence recognition in quiet and in babble, as well as measures of quality of life (QOL). Results The CAR approach was feasible, but this pilot study was underpowered to determine efficacy. Differential time courses of speech recognition improvement were seen for sentence and word recognition. All QOL measurements showed improvement from pre‐CI to 1 month post‐CI activation. Results revealed issues to consider for a larger‐scale study of CAR revolving around participant selection, study measures, and sample size. Conclusion The CAR approach is feasible in new CI users. A larger trial is needed to investigate whether CAR leads to better outcomes or faster improvement in this clinical population. Level of Evidence 2.

An Analysis of Nonsignificant Results in Audiology Using Bayes Factors

Article

Dec 2019

Purpose Null hypothesis significance testing is commonly used in audiology research to determine the presence of an effect. Knowledge of study outcomes, including nonsignificant findings, is important for evidence-based practice. Nonsignificant p values obtained from null hypothesis significance testing cannot differentiate between true null effects or underpowered studies. Bayes factors (BFs) are a statistical technique that can distinguish between conclusive and inconclusive nonsignificant results, and quantify the strength of evidence in favor of 1 hypothesis over another. This study aimed to investigate the prevalence of BFs in nonsignificant results in audiology research and the strength of evidence in favor of the null hypothesis in these results. Method Nonsignificant results mentioned in abstracts of articles published in 2018 volumes of 4 prominent audiology journals were extracted ( N = 108) and categorized based on whether BFs were calculated. BFs were calculated from nonsignificant t tests within this sample to determine how frequently the null hypothesis was strongly supported. Results Nonsignificant results were not directly tested with BFs in any study. Bayesian re-analysis of 93 nonsignificant t tests found that only 40.86% of findings provided moderate evidence in favor of the null hypothesis, and none provided strong evidence. Conclusion BFs are underutilized in audiology research, and a large proportion of null findings were deemed inconclusive when re-analyzed with BFs. Researchers are encouraged to use BFs to test the validity and strength of evidence of nonsignificant results and ensure that sufficient sample sizes are used so that conclusive findings (significant or not) are observed more frequently. Supplemental Material https://osf.io/b4kc7/

Effects of spectral degradation on gated word recognition

Article

Full-text available

Aug 2023

Although much is known about how normal-hearing listeners process spoken words under ideal listening conditions, little is known about how a degraded signal, such as speech transmitted via cochlear implants, affects the word recognition process. In this study, gated word recognition performance was measured with the goal of describing the time course of word identification by using a noise-band vocoder simulation. The results of this study demonstrate that spectral degradations can impact the temporal aspects of speech processing. These results also provide insights into the potential advantages of enhancing spectral resolution in the processing of spoken words.

Effortful Listening Despite Correct Responses: The Cost of Mental Repair in Sentence Recognition by Listeners With Cochlear Implants

Article

Full-text available

Sep 2022

Purpose Speech recognition percent correct scores fail to capture the effort of mentally repairing the perception of speech that was initially misheard. This study measured the effort of listening to stimuli specifically designed to elicit mental repair in adults who use cochlear implants (CIs). Method CI listeners heard and repeated sentences in which specific words were distorted or masked by noise but recovered based on later context: a signature of mental repair. Changes in pupil dilation were tracked as an index of effort and time-locked with specific landmarks during perception. Results Effort significantly increases when a listener needs to repair a misperceived word, even if the verbal response is ultimately correct. Mental repair of words in a sentence was accompanied by greater prevalence of errors elsewhere in the same sentence, suggesting that effort spreads to consume resources across time. The cost of mental repair in CI listeners was essentially the same as that observed in listeners with normal hearing in previous work. Conclusions Listening effort as tracked by pupil dilation is better explained by the mental repair and reconstruction of words rather than the appearance of correct or incorrect perception. Linguistic coherence drives effort more heavily than the mere presence of mistakes, highlighting the importance of testing materials that do not constrain coherence by design.

Can Cochlear Implantation in Older Adults Reverse Cognitive Decline Due to Hearing Loss?

Article

May 2021

Introduction: Older adults with late-onset hearing loss are at risk for cognitive decline. Our study addresses the question of whether cochlear implantation (CI) can counteract this potential influence. We investigated whether cognitive performance in older adults with severe and profound hearing loss improves 12 months after CI to a level comparable to controls with normal hearing, matched for age, sex, and education level. Design: This cohort study was performed at two tertiary referral centers. The study included 29 patients, of age between 60 and 80 years, with adult-onset, severe to profound bilateral sensorineural hearing loss and indication for CI (study group), as well as 29 volunteers with age-adjusted hearing abilities, according to the norm curves of ISO-702 9:2000-01, (control group). Before CI and 12 months after CI, participants completed a neurocognitive test battery including tests of global cognition, verbal and figural episodic memory, and executive functions (attentional control, inhibition, and cognitive flexibility). Results: Twelve months after CI, the performance of the study group improved significantly in global cognition, compared to the situation before CI. Differences in verbal episodic memory, figural episodic memory, and executive function were not significant. Moreover, the improvement of the study group was significantly larger only in global cognition compared to the control group. Noninferiority tests on the cognitive performances of the study group after CI revealed that comparable levels to normal hearing controls were reached only in global cognition, figural episodic memory (immediate recall), and attentional control. The improvement in global cognition was significantly associated with speech recognition 3 months after CI, but not with speech recognition 12 months after CI. Conclusion: One year after CI, cognitive deficits in older individuals with adult-onset hearing loss, compared to normal-hearing peers, could only improve some cognitive skills.

Considerations for Integrating Cognitive Testing Into Adult Cochlear Implant Evaluations—Foundations for the Future

Article

Feb 2021

The concept that hearing and cognitive functions are linked emerged decades ago.¹ With the growth of this interdisciplinary field of cognitive hearing science, the complex relationships between hearing and cognition have become better elucidated. More specifically, in older adults with hearing loss (HL), 3 areas of research have advanced our understanding of hearing and cognition. First, it is clear that HL is associated with cognitive decline, and the degree of HL appears to be associated with the risk of cognitive dysfunction in a dose-dependent manner.² Second, recent studies³ suggest positive associations of hearing rehabilitation with cognitive abilities. Third, there is growing evidence that communication and speech recognition outcomes with hearing aids and cochlear implants (CIs) are influenced by the cognitive abilities of the user.

Relationship Between Electrocochleography, Angular Insertion Depth, and Cochlear Implant Speech Perception Outcomes

Article

Dec 2020

Objectives: Electrocochleography (ECochG), obtained before the insertion of a cochlear implant (CI) array, provides a measure of residual cochlear function that accounts for a substantial portion of variability in postoperative speech perception outcomes in adults. It is postulated that subsequent surgical factors represent independent sources of variance in outcomes. Prior work has demonstrated a positive correlation between angular insertion depth (AID) of straight arrays and speech perception under the CI-alone condition, with an inverse relationship observed for precurved arrays. The purpose of the present study was to determine the combined effects of ECochG, AID, and array design on speech perception outcomes. Design: Participants were 50 postlingually deafened adult CI recipients who received one of three straight arrays (MED-EL Flex24, MED-EL Flex28, and MED-EL Standard) and two precurved arrays (Cochlear Contour Advance and Advanced Bionics HiFocus Mid-Scala). Residual cochlear function was determined by the intraoperative ECochG total response (TR) measured before array insertion, which is the sum of magnitudes of spectral components in response to tones of different stimulus frequencies across the speech spectrum. The AID was then determined with postoperative imaging. Multiple linear regression was used to predict consonant-nucleus-consonant (CNC) word recognition in the CI-alone condition at 6 months postactivation based on AID, TR, and array design. Results: Forty-one participants received a straight array and nine received a precurved array. The AID of the most apical electrode contact ranged from 341° to 696°. The TR measured by ECochG accounted for 43% of variance in speech perception outcomes (p < 0.001). A regression model predicting CNC word scores with the TR tended to underestimate the performance for precurved arrays and deeply inserted straight arrays, and to overestimate the performance for straight arrays with shallower insertions. When combined in a multivariate linear regression, the TR, AID, and array design accounted for 72% of variability in speech perception outcomes (p < 0.001). Conclusions: A model of speech perception outcomes that incorporates TR, AID, and array design represents an improvement over a model based on TR alone. The success of this model shows that peripheral factors including cochlear health and electrode placement may play a predominant role in speech perception with CIs.

A surgeon‐scientist' s perspective and review of cognitive‐linguistic contributions to adult cochlear implant outcomes

Article

Full-text available

Nov 2020

Aaron Moberly

Objective(s) Enormous variability in speech recognition outcomes persists in adults who receive cochlear implants (CIs), which leads to a barrier to progress in predicting outcomes before surgery, explaining “poor” outcomes, and determining how to provide tailored rehabilitation therapy for individual CI users. The primary goal of my research program over the past 9 years has been to extend our understanding of the contributions of “top‐down” cognitive‐linguistic skills to CI outcomes in adults, acknowledging that “bottom‐up” sensory processes also contribute substantially. The main objective of this invited narrative review is to provide an overview of this work. A secondary objective is to provide career “guidance points” to budding surgeon‐scientists in Otolaryngology. Methods A narrative, chronological review covers work done by our group to explore top‐down and bottom‐up processing in adult CI outcomes. A set of ten guidance points is also provided to assist junior Otolaryngology surgeon‐scientists. Results Work in our lab has identified substantial contributions of cognitive skills (working memory, inhibition‐concentration, speed of lexical access, nonverbal reasoning, verbal learning and memory) as well as linguistic abilities (acoustic cue‐weighting, phonological sensitivity) to speech recognition outcomes in adults with CIs. These top‐down skills interact with the quality of the bottom‐up input. Conclusion Although progress has been made in understanding speech recognition variability in adult CI users, future work is needed to predict CI outcomes before surgery, to identify particular patients' strengths and weaknesses, and to tailor rehabilitation approaches for individual CI users. Level of Evidence 4

Neural mechanisms of AVPR1A RS3-RS1 haplotypes that impact verbal learning and memory

Article

Full-text available

Aug 2020

Converging evidence from both human and animal studies has highlighted the pervasive role of the neuropeptide arginine vasopressin (AVP), which is mediated by arginine vasopressin receptor 1A (AVPR1A), in both social and nonsocial learning and memory. However, the effect of genetic variants in AVPR1A on verbal learning and memory is unknown. The hippocampus is a heterogeneous structure that consists of several anatomically and functionally distinct subfields, and it is the principal target structure for the memory-enhancing effect of AVP. We tested the hypothesis that genetic variants in the RS3 and RS1 repeat polymorphisms may influence verbal learning and memory performance evaluated by the California Verbal Learning Test-II (CVLT-II) by modulating the gray matter volume (GMV) and resting-state functional connectivity (rsFC) of whole hippocampus and its subfields in a large cohort of young healthy subjects (n = 1,001). Using a short/long classification scheme for the repeat length of RS3 and RS1, we found that the individuals carrying more short alleles of RS3-RS1 haplotypes had poorer learning and memory performance compared to that of those carrying more long alleles. We also revealed that individuals carrying more short alleles exhibited a significantly smaller GMV in the left cornu ammonis (CA)2/3 and weaker rsFC of the left CA2/3-bilateral thalamic (primarily in medial prefrontal subfields) compared to those carrying more long alleles. Furthermore, multiple mediation analysis confirmed that these two hippocampal imaging measures jointly and fully mediated the relationship between the genetic variants in AVPR1A RS3-RS1 haplotypes and the individual differences in verbal learning and memory performance. Our results suggest that genetic variants in AVPR1A RS3-RS1 haplotypes may affect verbal learning and memory performance in part by modulating the left hippocampal CA2/3 structure and its rsFC with the thalamus.

Performance on the Standard and Hearing‐Impaired Montreal Cognitive Assessment in Cochlear Implant Users

Article

Jan 2020

Objectives: Commonly-used cognitive screening tools were not originally developed for patients with hearing loss (HL), and rely heavily on the ability to hear the instructions and test stimuli. Recently, the Montreal Cognitive Assessment (MoCA) was modified for use with hearing-impaired populations (i.e., HI-MoCA). In order to investigate the clinical utility of the HI-MoCA, we assessed performance between the standard and HI-MoCA among post-lingually deafened cochlear implant (CI) users. Methods: We administered the standard and HI-MoCA to 21 CI users and compared their overall performance and assessed the differences in pass/fail status when items from the Attention and Language sections and the delayed recall task were removed. Results: There was no significant difference in performance between the standard and HI-MoCA. Participants scored higher on both test versions when the delayed recall task was removed. Participants also performed better on the delayed recall task on the HI-MoCA than on the standard MoCA. Conclusions: While our findings suggest that the modality of presentation for the MoCA does not influence overall performance for post-lingually deafened CI users, visual presentation of stimuli impacted performance on delayed recall. Furthermore, irrespective of presentation modality, our participants scored higher on both MoCA versions when the delayed recall task was removed. Clinically, modifications to the presentation of the MoCA might not be necessary for CI users, however, clinicians should be aware that the delayed recall task is inherently harder for these patients. This article is protected by copyright. All rights reserved.

Cognitive Functions in Adults Receiving Cochlear Implants: Predictors of Speech Recognition and Changes After Implantation

Article

Full-text available

Dec 2019

Hypotheses: Significant variability in speech recognition outcomes is consistently observed in adults who receive cochlear implants (CIs), some of which may be attributable to cognitive functions. Two hypotheses were tested: 1) preoperative cognitive skills assessed visually would predict postoperative speech recognition at 6 months after CI; and 2) cochlear implantation would result in benefits to cognitive processes at 6 months. Background: Several executive functioning tasks have been identified as contributors to speech recognition in adults with hearing loss. There is also mounting evidence that cochlear implantation can improve cognitive functioning. This study examined whether preoperative cognitive functions would predict speech recognition after implantation, and whether cognitive skills would improve as a result of CI intervention. Methods: Nineteen post-lingually deafened adult CI candidates were tested preoperatively using a visual battery of tests to assess working memory (WM), processing speed, inhibition-concentration, and nonverbal reasoning. Six months post-implantation, participants were assessed with a battery of word and sentence recognition measures and cognitive tests were repeated. Results: Multiple speech measures after 6 months of CI use were correlated with preoperative visual WM (symbol span task) and inhibition ability (stroop incongruent task) with moderate-to-large effect sizes. Small-to-large effect size improvements in visual WM, concentration, and inhibition tasks were found from pre- to post-CI. Patients with lower baseline cognitive abilities improved the most after implantation. Conclusions: Findings provide evidence that preoperative cognitive factors contribute to speech recognition outcomes for adult CI users, and support the premise that implantation may lead to improvements in some cognitive domains.

High- and Low-Performing Adult Cochlear Implant Users on High-Variability Sentence Recognition: Differences in Auditory Spectral Resolution and Neurocognitive Functioning

Article

Sep 2019
J Am Acad Audiol

Background: Postlingually deafened adult cochlear implant (CI) users routinely display large individual differences in the ability to recognize and understand speech, especially in adverse listening conditions. Although individual differences have been linked to several sensory ("bottom-up") and cognitive ("top-down") factors, little is currently known about the relative contributions of these factors in high- and low-performing CI users. Purpose: The aim of the study was to investigate differences in sensory functioning and neurocognitive functioning between high- and low-performing CI users on the Perceptually Robust English Sentence Test Open-set (PRESTO), a high-variability sentence recognition test containing sentence materials produced by multiple male and female talkers with diverse regional accents. Research design: CI users with accuracy scores in the upper (HiPRESTO) or lower quartiles (LoPRESTO) on PRESTO in quiet completed a battery of behavioral tasks designed to assess spectral resolution and neurocognitive functioning. Study sample: Twenty-one postlingually deafened adult CI users, with 11 HiPRESTO and 10 LoPRESTO participants. Data collection and analysis: A discriminant analysis was carried out to determine the extent to which measures of spectral resolution and neurocognitive functioning discriminate HiPRESTO and LoPRESTO CI users. Auditory spectral resolution was measured using the Spectral-Temporally Modulated Ripple Test (SMRT). Neurocognitive functioning was assessed with visual measures of working memory (digit span), inhibitory control (Stroop), speed of lexical/phonological access (Test of Word Reading Efficiency), and nonverbal reasoning (Raven's Progressive Matrices). Results: HiPRESTO and LoPRESTO CI users were discriminated primarily by performance on the SMRT and secondarily by the Raven's test. No other neurocognitive measures contributed substantially to the discriminant function. Conclusions: High- and low-performing CI users differed by spectral resolution and, to a lesser extent, nonverbal reasoning. These findings suggest that the extreme groups are determined by global factors of richness of sensory information and domain-general, nonverbal intelligence, rather than specific neurocognitive processing operations related to speech perception and spoken word recognition. Thus, although both bottom-up and top-down information contribute to speech recognition performance, low-performing CI users may not be sufficiently able to rely on neurocognitive skills specific to speech recognition to enhance processing of spectrally degraded input in adverse conditions involving high talker variability.

High- and Low-Performing Adult Cochlear Implant Users on High-Variability Sentence Recognition: Differences in Auditory Spectral Resolution and Neurocognitive Functioning

Article

Jan 2019

What to Do When Cochlear Implant Users Plateau in Performance: a Pilot Study of Clinician-guided Aural Rehabilitation

Article

Oct 2018
OTOL NEUROTOL

Hypothesis: For experienced adult cochlear implant (CI) users who have reached a plateau in performance, a clinician-guided aural rehabilitation (CGAR) approach can improve speech recognition and hearing-related quality of life (QOL). Background: A substantial number of CI users do not reach optimal performance in terms of speech recognition ability and/or personal communication goals. Although self-guided computerized auditory training programs have grown in popularity, compliance and efficacy for these programs are poor. We propose that CGAR can improve speech recognition and hearing-related QOL in experienced CI users. Methods: Twelve adult CI users were enrolled in an 8-week CGAR program guided by a speech-language pathologist and audiologist. Nine patients completed the program along with pre-AR and immediate post-AR testing of speech recognition (AzBio sentences in quiet and in multitalker babble, Consonant-Nucleus-Consonant words in quiet), QOL (Nijmegen Cochlear Implant Questionnaire, Hearing Handicap Inventory for Adults/Elderly, and Speech, Spatial and Qualities of Hearing Scale), and neurocognitive functioning (working memory capacity, information-processing speed, inhibitory control, speed of lexical/phonological access, and nonverbal reasoning). Pilot data for these nine patients are presented. Results: From pre-CGAR to post-CGAR, group mean improvements in word recognition were found. Improvements were also demonstrated on some composite and subscale measures of QOL. Patients who demonstrated improvements in word recognition were those who performed most poorly at baseline. Conclusions: CGAR represents a potentially efficacious approach to improving speech recognition and QOL for experienced CI users. Limitations and considerations in implementing and studying aural rehabilitation approaches are discussed.

Neurocognitive Factors Contributing to Cochlear Implant Candidacy

Article

Dec 2018

Hypothesis: Clinical adult cochlear implant (CI) candidacy evaluations rely heavily on measures of sentence recognition under the best-aided listening conditions. The hypothesis tested in this study was that nonauditory measures of neurocognitive processes would contribute to scores on preoperative sentence recognition for CI candidates, above and beyond hearing ability as assessed using pure-tone average (PTA). Support for this hypothesis would suggest that best-aided sentence recognition is not simply a measure of hearing ability; rather, neurocognitive functions contribute to performance and should be considered while counseling patients during CI candidacy evaluation about postoperative rehabilitative and outcome expectations. Background: Neurocognitive functions, such as working memory capacity, inhibition-concentration, information processing speed, and nonverbal reasoning contribute to aided speech recognition outcomes in adults with hearing loss. This study examined the roles of these neurocognitive factors on preoperative speech recognition performance in adults evaluated for CI candidacy. Methods: Thirty-one postlingually deafened adult CI candidates were enrolled. Participants were assessed using nonauditory measures of working memory capacity, inhibition-concentration, information processing speed, and nonverbal reasoning. Measures of sentence recognition in quiet and in multitalker babble (AzBio sentences) as well as sentences from the City University of New York in quiet were collected under best-aided conditions. Results: AzBio sentence recognition scores in babble were predicted significantly by scores of working memory capacity after accounting for PTA. Similarly, the City University of New York sentence recognition scores were predicted significantly by nonverbal reasoning after accounting for PTA. Conclusions: Findings support the idea that clinical measures of sentence recognition may be affected to varying degrees by neurocognitive functions, and these functions should be considered during evaluation for CI candidacy.

Cognitive Functions in Adult Cochlear Implant Users, Cochlear Implant Candidates, and Normal-Hearing Listeners: Cognitive functions in cochlear implant users

Article

Full-text available

Aug 2018

Objectives Increasing evidence suggests that hearing loss may be linked to cognitive decline, and that cochlear implantation may lead to improvements in cognition. The goal of this study was to examine the effects of severe‐to‐profound hearing loss and cochlear implantation in post‐lingually deafened adults, compared with age‐matched normal‐hearing (NH) peers. Participants were tested on several non‐auditory measures of cognition: working memory (WM) (digit span, object span, symbol span), non‐verbal reasoning (Raven's progressive matrices), information‐processing speed and inhibitory control (Stroop test), speed of phonological and lexical access (Test of Word Reading Efficiency), and verbal learning and memory (California Verbal Learning Test). Demographic measures were also collected. Methods Cohort study at tertiary neurotology center. Forty‐three post‐lingually deafened experienced CI users, 19 post‐lingually deafened CI candidates, and 40 age‐matched NH controls with no cognitive impairment were enrolled. Comparisons among the groups on the cognitive measures were performed. Results Adult CI users and CI candidates demonstrated worse (or a trend towards worse) performance as compared with NH peers on non‐verbal reasoning, information‐processing speed, speed of lexical access, and verbal learning and memory. However, after controlling for gender, socioeconomic status (SES), and vocabulary knowledge among groups, some of these differences were no longer significant. Similarly, large differences were not found in most cognitive abilities between experienced CI users and CI candidates. Conclusions Adult CI users, CI candidates, and NH peers generally demonstrated equivalent non‐auditory cognitive abilities, after controlling for gender, SES, and vocabulary knowledge. These findings provide support for a link between cognitive decline and hearing loss, but this association may be partly attributable to group differences in SES and vocabulary knowledge. Level of Evidence 2b.

Systematic Review with or without Meta-analysis Emerging Relations among Cognitive Constructs and Cochlear Implant Outcomes: A Systematic Review and Meta-Analysis

Article

Jun 2023
OTOLARYNG HEAD NECK

Objective: Hearing loss has a detrimental impact on cognitive function. However, there is a lack of consensus on the impact of cochlear implants on cognition. This review systematically evaluates whether cochlear implants in adult patients lead to cognitive improvements and investigates the relations of cognition with speech recognition outcomes. Data sources: A literature review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies evaluating cognition and cochlear implant outcomes in postlingual, adult patients from January 1996 to December 2021 were included. Of 2510 total references, 52 studies were included in qualitative analysis and 11 in meta-analyses. Review methods: Proportions were extracted from studies of (1) the significant impacts of cochlear implantation on 6 cognitive domains and (2) associations between cognition and speech recognition outcomes. Meta-analyses were performed using random effects models on mean differences between pre- and postoperative performance on 4 cognitive assessments. Results: Only half of the outcomes reported suggested cochlear implantation had a significant impact on cognition (50.8%), with the highest proportion in assessments of memory & learning and inhibition-concentration. Meta-analyses revealed significant improvements in global cognition and inhibition-concentration. Finally, 40.4% of associations between cognition and speech recognition outcomes were significant. Conclusion: Findings relating to cochlear implantation and cognition vary depending on the cognitive domain assessed and the study goal. Nonetheless, assessments of memory & learning, global cognition, and inhibition-concentration may represent tools to assess cognitive benefit after implantation and help explain variability in speech recognition outcomes. Enhanced selectivity in assessments of cognition is needed for clinical applicability.

Association of Cognitive Impairment Screening Scores With Improvements in Speech Recognition and Quality of Life After Cochlear Implantation

Article

Feb 2023

Importance: Many cochlear implant centers screen patients for cognitive impairment as part of the evaluation process, but the utility of these scores in predicting cochlear implant outcomes is unknown. Objective: To determine whether there is an association between cognitive impairment screening scores and cochlear implant outcomes. Design, setting, and participants: Retrospective case series of adult cochlear implant recipients who underwent preoperative cognitive impairment screening with the Montreal Cognitive Assessment (MoCA) from 2018 to 2020 with 1-year follow-up at a single tertiary cochlear implant center. Data analysis was performed on data from January 2018 through December 2021. Exposures: Cochlear implantation. Main outcomes and measures: Preoperative MoCA scores and mean (SD) improvement (aided preoperative to 12-month postoperative) in Consonant-Nucleus-Consonant phonemes (CNCp) and words (CNCw), AzBio sentences in quiet (AzBio Quiet), and Cochlear Implant Quality of Life-35 (CIQOL-35) Profile domain and global scores. Results: A total of 52 patients were included, 27 (52%) of whom were male and 46 (88%) were White; mean (SD) age at implantation was 68.2 (13.3) years. Twenty-three (44%) had MoCA scores suggesting mild and 1 (2%) had scores suggesting moderate cognitive impairment. None had been previously diagnosed with cognitive impairment. There were small to medium effects of the association between 12-month postoperative improvement in speech recognition measures and screening positive or not for cognitive impairment (CNCw mean [SD]: 48.4 [21.9] vs 38.5 [26.6] [d = -0.43 (95% CI, -1.02 to 0.16)]; AzBio Quiet mean [SD]: 47.5 [34.3] vs 44.7 [33.1] [d = -0.08 (95% CI, -0.64 to 0.47)]). Similarly, small to large effects of the associations between 12-month postoperative change in CIQOL-35 scores and screening positive or not for cognitive impairment were found (global: d = 0.32 [95% CI, -0.59 to 1.23]; communication: d = 0.62 [95% CI, -0.31 to 1.54]; emotional: d = 0.26 [95% CI, -0.66 to 1.16]; entertainment: d = -0.005 [95% CI, -0.91 to 0.9]; environmental: d = -0.92 [95% CI, -1.86 to 0.46]; listening effort: d = -0.79 [95% CI, -1.65 to 0.22]; social: d = -0.51 [95% CI, -1.43 to 0.42]). Conclusions and relevance: In this case series, screening scores were not associated with the degree of improvement of speech recognition or patient-reported outcome measures after cochlear implantation. Given the prevalence of screening positive for cognitive impairment before cochlear implantation, preoperative screening can be useful for early identification of potential cognitive decline. These findings support that screening scores may have a limited role in preoperative counseling of outcomes and should not be used to limit candidacy.

Publication trends in cochlear implantation outcome measures

Article

Jun 2022

Objective To review trends in outcome domains and instruments reported by modern researchers in 100 consecutively published articles on cochlear implantation (CI). Methods Retrograde literature review of Medline, EMBASE and Cochrane Databases of 100 consecutive scientific publications. Outcome domains and instruments from each included study were extracted in categories: speech perception, speech development, sound perception, electrophysiological and quality of life. Results 61 studies met inclusion criteria. 84 outcome measures were reported in total across all 61 studies. Across the 42 studies reporting speech perception, 31 different measures were utilised. Categories of Auditory Performance (CAP) and Consonant Nucleus Consonant (CNC) were the most frequently used instruments. Nine studies reported speech development, with 11 different instruments used. Speech Intelligibility Rating (SIR) was most frequently used instrument. Sixteen studies reported on sound perception, with Pure Tone Audiometry (PTA) being the most frequently used instrument. Eleven studies reported six different electrophysiological instruments, with Auditory Brainstem Response (ABR) being used most frequently used. Two studies measured quality of life outcome, with three instruments used. Conclusion This study confirms a large degree of CI outcome heterogeneity within the peer reviewed literature. Determining consensus on core outcome domains and recommended instruments may increase the future impact and generalisability of work undertaken.

Recent Trends in Cochlear Implant Programming and (Re)habilitation

Chapter

Jan 2022

Whilst cochlear implant technology has continued to evolve significantly over the past 40 years, and the candidacy criteria have expanded, guidelines and standards for the programming and rehabilitation with cochlear implants remain globally undefined. This is consistent with other realms of the cochlear implant, such as candidacy. Boisvert et al. (PLoS One 15(5):e0232421, 2020) found that adults who may benefit from cochlear implantation may not meet the restricted or ambiguous criteria found in clinics across the globe. Further, heterogeneity of assessment tools used to identify candidacy and perform ongoing monitoring, contributes to inconsistency in predicting outcomes. The high variability of outcomes in the adult cochlear implant population raises questions when trying to determine contributing factors. Variability and sensitivity in methodologies used for device programming, assessment, and rehabilitation are compounded by the individual characteristics of the cochlear implant recipient. The aim of this chapter is to review recent and current approaches to programming and (re)habilitation in cochlear implants and to identify ways we can catalyse a shift to ensure all recipients not only reach their true potential, but continue to benefit from the advances offered in the cochlear implant space throughout their lifetime.KeywordsCI mappingCI device programmingCI device fittingCI rehabilitation; CI habilitation, CI (re)habilitationCI device activation; CI “switch on”CI map verification

Preoperative Visual Measures of Verbal Learning and Memory and their Relations to Speech Recognition After Cochlear Implantation

Article

Mar 2022
Ear Hear

Objectives: This study examined the performance of a group of adult cochlear implant (CI) candidates (CIC) on visual tasks of verbal learning and memory. Preoperative verbal learning and memory abilities of the CIC group were compared with a group of older normal-hearing (ONH) control participants. Relations between preoperative verbal learning and memory measures and speech recognition outcomes after 6 mo of CI use were also investigated for a subgroup of the CICs. Design: A group of 80 older adult participants completed a visually presented multitrial free recall task. Measures of word recall, repetition learning, and the use of self-generated organizational strategies were collected from a group of 49 CICs, before cochlear implantation, and a group of 31 ONH controls. Speech recognition outcomes were also collected from a subgroup of 32 of the CIC participants who returned for testing 6 mo after CI activation. Results: CICs demonstrated poorer verbal learning performance compared with the group of ONH control participants. Among the preoperative verbal learning and memory measures, repetition learning slope and measures of self-generated organizational clustering strategies were the strongest predictors of post-CI speech recognition outcomes. Conclusions: Older adult CI candidates present with verbal learning and memory deficits compared with older adults without hearing loss, even on visual tasks that are independent from the direct effects of audibility. Preoperative verbal learning and memory processes reflecting repetition learning and self-generated organizational strategies in free recall were associated with speech recognition outcomes 6 months after implantation. The pattern of results suggests that visual measures of verbal learning may be a useful predictor of outcomes in postlingual adult CICs.

Some Neuromyths and Challenging Questions about Cochlear Implants

Article

Apr 2021

Cochlear implants (CI) are neural prostheses that have had a substantial and long‐lasting effect on spoken‐language processing in deaf adults and children. This chapter addresses several neuromyths about how CIs work as an interface between the sound environment and spoken‐language processing in the brain. It presents evidence that individual differences in working memory capacity, speed of information processing, and implicit learning of sequential patterns are related to speech and language outcomes in CI users. Working memory is one of several neurocognitive abilities based in the frontal cortex of the brain that are related to regulation and self‐control of attention, thoughts, and behaviours. Pediatric CI users may be at risk of atypical domain‐general abilities for sequence learning. The emerging interdisciplinary field of cognitive hearing science and cognitive audiology is concerned with how hearing and cognition interact to support speech understanding across the life span. Auditory training for CI users is a challenging and controversial issue.

The Sensitivity of the Electrically Stimulated Auditory Nerve to Amplitude Modulation Cues Declines With Advanced Age

Article

Apr 2021

Objectives: This study aimed to investigate effects of aging and duration of deafness on sensitivity of the auditory nerve (AN) to amplitude modulation (AM) cues delivered using trains of biphasic pulses in adult cochlear implant (CI) users. Design: There were 21 postlingually deaf adult CI users who participated in this study. All study participants used a Cochlear Nucleus device with a full electrode array insertion in the test ear. The stimulus was a 200-ms pulse train with a pulse rate of 2000 pulses per second. This carrier pulse train was sinusodially AM at four modulation rates (20, 40, 100, 200 Hz). The peak amplitude of the modulated pulse train was the maximum comfortable level (i.e., C level) measured for the carrier pulse train. The electrically evoked compound action potential (eCAP) to each of the 20 pulses selected over the last two AM cycles were measured. In addition, eCAPs to single pulses were measured with the probe levels corresponding to the levels of 20 selected pulses from each AM pulse train. There were seven electrodes across the array evaluated in 16 subjects (i.e., electrodes 3 or 4, 6, 9, 12, 15, 18, and 21). For the remaining five subjects, 4 to 5 electrodes were tested due to impedance issues or time constraints. The modulated response amplitude ratio (MRAR) was calculated as the ratio of the difference in the maximum and the minimum eCAP amplitude measured for the AM pulse train to that measured for the single pulse, and served as the dependent variable. Age at time of testing and duration of deafness measured/defined using three criteria served as the independent variables. Linear Mixed Models were used to assess the effects of age at testing and duration of deafness on the MRAR. Results: Age at testing had a strong, negative effect on the MRAR. For each subject, the duration of deafness varied substantially depending on how it was defined/measured, which demonstrates the difficulty of accurately measuring the duration of deafness in adult CI users. There was no clear or reliable trend showing a relationship between the MRAR measured at any AM rate and duration of deafness defined by any criteria. After controlling for the effect of age at testing, MRARs measured at 200 Hz and basal electrode locations (i.e., electrodes 3 and 6) were larger than those measured at any other AM rate and apical electrode locations (i.e., electrodes 18 and 21). Conclusions: The AN sensitivity to AM cues implemented in the pulse-train stimulation significantly declines with advanced age. Accurately measuring duration of deafness in adult CI users is challenging, which, at least partially, might have accounted for the inconclusive findings in the relationship between the duration of deafness and the AN sensitivity to AM cues in this study.

Meta-analytic findings on lower reading skills in children with cochlear implants

Preprint

Mar 2021

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. Of the 5,642 articles screened, 47 articles met predetermined inclusion criteria. The robust variance estimation based meta-analysis models were used to synthesize all the effect sizes. Children with cochlear implants performed significantly worse than their hearing peers for phonological awareness (g = -1.62, p < .001), vocabulary (g = -1.50, p < .001), decoding (g = -1.24, p < .001), and reading comprehension (g = -1.39, p < .001), but not for fluency (g = -.67, p = .054). Children with cochlear implants only scored significantly lower in phonological awareness (g = -.30, p = .028) than children with hearing aids. The only significant moderator was the percentage of unilateral cochlear implant that negatively impact 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 as a consequence of cochlear implantation despite the poor scores in all constructs.

Assessment of risk factors for postoperative cognitive dysfunction after coronary artery bypass surgery: a single-centre retrospective cohort study

Article

Full-text available

Jan 2021

Aim: To find out risk factors for postoperative cognitive dysfunction (POCD) after coronary artery bypass grafting (CABG), and to provide basis for clinical prevention of POCD. A total of 88 patients who underwent CABG were surveyed with Telephone Questionnaire (TICS-M) for their cognitive impairment after 3, 7, 21, 90, 180 days post-surgery. The occurrence of POCD was diagnosed by Neuropsychological Battery which included Vocabular Learning Test (VLT), Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT) and Symbol Digit Modalities Test (SDMT). The preoperative, intraoperative and postoperative risk factors were assessed by the χ2 or t test. Multivariate analysis was used to study the correlation between the risk factors and the occurrence of POCD. Age, aortic plaque, carotid artery stenosis, cerebrovascular disease, anesthesia time, the rate of decline in intraoperative hemoglobin concentration (ΔHb) and systemic inflammatory response syndrome (SIRS) score on postoperative day 2 had statistically significant (P<0.05) influence on the occurrence of POCD. Aortic plaque, carotid artery stenosis, anesthesia time and SIRS score (odds ratio (OR) value > 1, P<0.05) are the risk factors for POCD. The incidence of day-21 and -180 POCD was approximately 26.1 and 22.7%, respectively.

Impact of Cochlear Implantation on Neurocognitive Subdomains in Adult Cochlear Implant Recipients

Article

Jan 2021

Introduction: Age-related hearing loss affects about one-third of the population worldwide. Studies suggest that hearing loss may be linked to cognitive decline and auditory rehabilitation may improve cognitive functions. So far, the data are limited, and the underlying mechanisms are not fully understood. The study aimed to analyze the impact of cochlear implantation on cognition in a large homogeneous population of hearing-impaired adults using a comprehensive non-auditory cognitive assessment with regard to normal-hearing (NH) subjects. Material and methods: Seventy-one cochlear implant (CI) candidates with a postlingual, bilateral severe or profound hearing loss aged 66.3 years (standard deviation [SD] 9.2) and 105 NH subjects aged 65.96 years (SD 9.4) were enrolled. The computer-based neurocognitive tool applied included 11 subtests covering attention (M3), short- and long-term memory (recall and delayed recall), working memory (0- and 2-back, Operation Span [OSPAN] task), processing speed (Trail Making Test [TMT] A), mental flexibility (TMT B), inhibition (cFlanker and iFlanker), and verbal fluency. CI patients underwent a neurocognitive testing preoperatively as well as 12 months postoperatively. Impact of hearing status, age, gender, and education on cognitive subdomains was studied. Additionally, after controlling for education and age, cognitive performance of CI subjects (n = 41) was compared to that of NH (n = 34). Results: CI users achieved significantly better neurocognitive scores 12 months after cochlear implantation than before in most subtests (M3, [delayed] recall, 2-back, OSPAN, iFlanker, and verbal fluency; all p < 0.05) except for the TMT A and B. A significant correlation could be found between the postoperative improvement in speech perception and in the attentional task M3 (p = 0.01). Hearing status (p = 0.0006) had the strongest effect on attention, whereas education had a high impact on recall (p = 0.002), OSPAN (p = 0.0004), and TMT A (p = 0.005) and B (p = 0.003). Inhibition was mainly age-dependent with better results in younger subjects (p = 0.016). Verbal fluency was predicted by gender as females outperformed men (p = 0.009). Even after controlling for age and education NH subjects showed a significantly better performance than CI candidates in the recall (p = 0.03) and delayed recall (p = 0.01) tasks. Postoperatively, there was no significant difference between the 2 groups anymore. Conclusion: Impact of cochlear implantation on neurocognitive functions differs according to the cognitive subdomains. Postoperatively, CI recipients performed as good as age- and education-matched NH subjects.

Explaining Speech Recognition and Quality of Life Outcomes in Adult Cochlear Implant Users: Complementary Contributions of Demographic, Sensory, and Cognitive Factors

Article

May 2020

Hypotheses: Adult cochlear implant (CI) outcomes depend on demographic, sensory, and cognitive factors. However, these factors have not been examined together comprehensively for relations to different outcome types, such as speech recognition versus quality of life (QOL). Three hypotheses were tested: 1) speech recognition will be explained most strongly by sensory factors, whereas QOL will be explained more strongly by cognitive factors. 2) Different speech recognition outcome domains (sentences versus words) and different QOL domains (physical versus social versus psychological functioning) will be explained differentially by demographic, sensory, and cognitive factors. 3) Including cognitive factors as predictors will provide more power to explain outcomes than demographic and sensory predictors alone. Background: A better understanding of the contributors to CI outcomes is needed to prognosticate outcomes before surgery, explain outcomes after surgery, and tailor rehabilitation efforts. Methods: Forty-one adult postlingual experienced CI users were assessed for sentence and word recognition, as well as hearing-related QOL, along with a broad collection of predictors. Partial least squares regression was used to identify factors that were most predictive of outcome measures. Results: Supporting our hypotheses, speech recognition abilities were most strongly dependent on sensory skills, while QOL outcomes required a combination of cognitive, sensory, and demographic predictors. The inclusion of cognitive measures increased the ability to explain outcomes, mainly for QOL. Conclusions: Explaining variability in adult CI outcomes requires a broad assessment approach. Identifying the most important predictors depends on the particular outcome domain and even the particular measure of interest.

Performance Variability on Perceptual Discrimination Tasks in Profoundly Deaf Adults with Cochlear Implants

Article

Jan 2018
J COMMUN DISORD

The Studying Multiple Outcomes After Aural Rehabilitative Treatment Study: Study Design and Baseline Results

Article

Full-text available

Apr 2017

Hearing loss may affect critical domains of health and functioning in older adults. This article describes the rationale and design of the Studying Multiple Outcomes After Aural Rehabilitative Treatment (SMART) study, which was developed to determine to what extent current hearing rehabilitative therapies could mitigate the effects of hearing loss on health outcomes. One hundred and forty-five patients ≥50 years receiving hearing aids (HA) or cochlear implants (CI) were recruited from the Johns Hopkins Department of Otolaryngology-HNS. A standardized outcome battery was administered to assess cognitive, social, mental, and physical functioning. Of the 145 participants aged 50 to 94.9 years who completed baseline evaluations, CI participants had significantly greater loneliness, social isolation, and poorer hearing and communicative function compared with HA participants. This study showed that standardized measures of health-related outcomes commonly used in gerontology appear sensitive to hearing impairment and are feasible to implement in clinical studies of hearing loss.

Questionnaire-based assessment of executive functioning: Case studies

Article

Full-text available

Jul 2016

Delays in the development of executive functioning skills are frequently observed in pediatric neuropsychology populations and can have a broad and significant impact on quality of life. As a result, assessment of executive functioning is often relevant for the development of formulations and recommendations in pediatric neuropsychology clinical work. Questionnaire-based measures of executive functioning behaviors in everyday life have unique advantages and complement traditional neuropsychological measures of executive functioning. Two case studies of children with spina bifida are presented to illustrate the clinical use of a new questionnaire measure of executive and learning-related functioning, the Learning, Executive, and Attention Functioning Scale (LEAF). The LEAF emphasizes clinical utility in assessment by incorporating four characteristics: brevity in administration, breadth of additional relevant content, efficiency of scoring and interpretation, and ease of availability for use. LEAF results were consistent with another executive functioning checklist in documenting everyday behavior problems related to working memory, planning, and organization while offering additional breadth of assessment of domains such as attention, processing speed, and novel problem-solving. These case study results demonstrate the clinical utility of questionnaire-based measurement of executive functioning in pediatric neuropsychology and provide a new measure for accomplishing this goal.

Learning and Memory Processes Following Cochlear Implantation: The Missing Piece of the Puzzle

Article

Full-text available

Apr 2016

At the present time, there is no question that cochlear implants work and often work very well in quiet listening conditions for many profoundly deaf children and adults. The speech and language outcomes data published over the last two decades document quite extensively the clinically significant benefits of cochlear implants. Although there now is a large body of evidence supporting the "efficacy" of cochlear implants as a medical intervention for profound hearing loss in both children and adults, there still remain a number of challenging unresolved clinical and theoretical issues that deal with the "effectiveness" of cochlear implants in individual patients that have not yet been successfully resolved. In this paper, we review recent findings on learning and memory, two central topics in the field of cognition that have been seriously neglected in research on cochlear implants. Our research findings on sequence learning, memory and organization processes, and retrieval strategies used in verbal learning and memory of categorized word lists suggests that basic domain-general learning abilities may be the missing piece of the puzzle in terms of understanding the cognitive factors that underlie the enormous individual differences and variability routinely observed in speech and language outcomes following cochlear implantation.

Quality of life and audiologic performance through the ability to phone of cochlear implant users

Article

Full-text available

Dec 2015
Eur Arch Oto Rhino Laryngol

This study aimed to evaluate the impact of cochlear implantation on quality of life (QoL), using gen-eral and cochlear implant (CI) specific questionnaires and to determine the relationship of phone ability with QoL, speech recognition abilities and tinnitus. Twenty-six adult volunteers with a post-lingual profound deafness, unilat-erally implanted with a CI, were included in this study. All subjects had used a CI for at least 1 year. The Glasgow benefit inventory (GBI) and Nijmegen cochlear implant questionnaire (NCIQ) were administered to assess QoL. Speech recognition was tested using phonemic Lafon's lists. The subjective tinnitus severity scale (STSS) ques-tionnaire was used to determine the effects of tinnitus. CI users were split into four groups according to their phone ability. There was an improvement in QoL after cochlear implantation. The NCIQ showed significant (p \ 0.001) improvements in the total score and in all subdomains after CI. A significant relationship between phone ability, QoL and speech recognition was found. Improving phone ability led to higher QoL (p \ 0.05) and speech recognition (p \ 0.01) scores. The CI use decreased significantly the occurrence of tinnitus, but its severity was not correlated with QoL. Post-surgery assessment should include speech recognition measures and QoL evaluation. The NCIQ appeared more effective than the GBI in its ability to detect improvements in QoL. Assessing phone ability represents an easy and fast approach to evaluate hearing performances and QoL, and may reflect global outcomes of CI. Keywords Audiometry Á Cochlear implants Á Quality of life Á Tinnitus Á Phone ability Abbreviations CI Cochlear implant GBI Glasgow benefit inventory HRQoL Health-related quality of life NCIQ Nijmegen Cochlear Implant Questionnaire QoL Quality of life STSS Subjective tinnitus severity scale Introduction

The Ease of Language Understanding (ELU) Model: Theoretical, empirical, and clinical advances

Article

Full-text available

Jul 2013

Working memory is important for online language processing during conversation. We use it to maintain relevant information, to inhibit or ignore irrelevant information, and to attend to conversation selectively. Working memory helps us to keep track of and actively participate in conversation, including taking turns and following the gist. This paper examines the Ease of Language Understanding model (i.e., the ELU model, Rönnberg, 2003; Rönnberg et al., 2008) in light of new behavioral and neural findings concerning the role of working memory capacity (WMC) in uni-modal and bimodal language processing. The new ELU model is a meaning prediction system that depends on phonological and semantic interactions in rapid implicit and slower explicit processing mechanisms that both depend on WMC albeit in different ways. It is based on findings that address the relationship between WMC and (a) early attention processes in listening to speech, (b) signal processing in hearing aids and its effects on short-term memory, (c) inhibition of speech maskers and its effect on episodic long-term memory, (d) the effects of hearing impairment on episodic and semantic long-term memory, and finally, (e) listening effort. New predictions and clinical implications are outlined. Comparisons with other WMC and speech perception models are made.

The Hopkins Verbal Learning Test: Development of a new memory test with six equivalent forms

Article

Full-text available

Apr 1991

Jason Brandt

A new test of verbal learning and memory, the Hopkins Verbal Learning Test, was developed. The test consists of three trials of free-recall of a 12-item, semantically categorized list, followed by yes/no recognition. Six parallel forms yielded equivalent results in normals. The performance of patients with Alzheimer's disease and chronic amnesia is described. The test is likely to be useful in patients too impaired for more comprehensive memory assessments and where repeated testing is necessary.

Efficacy and Effectiveness of Cochlear Implants in Deaf Children 1

Article

Full-text available

Jul 2008

This chapter explores the large individual differences in speech and language outcomes in deaf children who have received cochlear implants (CIs). It argues that that the variability in performance on the traditional clinical outcome measures used to assess speech and language processing skills in deaf children with CIs reflects fundamental differences in the speed of information processing operations such as verbal rehearsal, scanning of items in short-term memory, and the rate of encoding phonological and lexical information in working memory. It is also shown that the sequela of deafness and delay in language are not domain-specific and restricted to only hearing and auditory processing. Other neurocognitive systems display disturbances, and these differences appear to reflect the operation of domain-general processes of cognitive control, self-regulation, and organization. © 2008 by Marc Marschark and Peter C. Hauser. All rights reserved.

Pre-, Per- and Postoperative Factors Affecting Performance of Postlinguistically Deaf Adults Using Cochlear Implants: A New Conceptual Model over Time

Article

Full-text available

Nov 2012
PLOS ONE

OBJECTIVE: To test the influence of multiple factors on cochlear implant (CI) speech performance in quiet and in noise for postlinguistically deaf adults, and to design a model of predicted auditory performance with a CI as a function of the significant factors. STUDY DESIGN: Retrospective multi-centre study. METHODS: Data from 2251 patients implanted since 2003 in 15 international centres were collected. Speech scores in quiet and in noise were converted into percentile ranks to remove differences between centres. The influence of 15 pre-, per- and postoperative factors, such as the duration of moderate hearing loss (mHL), the surgical approach (cochleostomy or round window approach), the angle of insertion, the percentage of active electrodes, and the brand of device were tested. The usual factors, duration of profound HL (pHL), age, etiology, duration of CI experience, that are already known to have an influence, were included in the statistical analyses. RESULTS: THE SIGNIFICANT FACTORS WERE: the pure tone average threshold of the better ear, the brand of device, the percentage of active electrodes, the use of hearing aids (HAs) during the period of pHL, and the duration of mHL. CONCLUSIONS: A new model was designed showing a decrease of performance that started during the period of mHL, and became faster during the period of pHL. The use of bilateral HAs slowed down the related central reorganization that is the likely cause of the decreased performance.

Proactive Interference and the Dynamics of Free Recall

Article

Full-text available

Sep 1993

Proactive interference (PI) has long been recognized as a major cause of forgetting. Two experiments were conducted that offer another look at the subject by providing a detailed analysis of recall latency distributions during the buildup of and release from PI. These functions were accurately characterized by the convolution of the normal and exponential distributions (viz., the ex-Gaussian), which previously has been shown to describe recognition latency distributions. Further, the fits revealed that the increase in recall latency associated with the buildup of PI results from a slowing of the exponential retrieval stage only. The same result was found even when a short retention interval was used (and recall probability remained constant). These findings suggest that free-recall latency may be a sensitive index of the increased search set size that has often been assumed to accompany the buildup of PI. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Hearing Loss and Cognition in the Baltimore Longitudinal Study of Aging

Article

Full-text available

Jul 2011
NEUROPSYCHOLOGY

To determine the relationship between hearing loss and cognitive function as assessed with a standardized neurocognitive battery. We hypothesized a priori that greater hearing loss is associated with lower cognitive test scores on tests of memory and executive function. A cross-sectional cohort of 347 participants ≥ 55 years in the Baltimore Longitudinal Study of Aging without mild cognitive impairment or dementia had audiometric and cognitive testing performed in 1990-1994. Hearing loss was defined by an average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear. Cognitive testing consisted of a standardized neurocognitive battery incorporating tests of mental status, memory, executive function, processing speed, and verbal function. Regression models were used to examine the association between hearing loss and cognition while adjusting for confounders. Greater hearing loss was significantly associated with lower scores on measures of mental status (Mini-Mental State Exam), memory (Free Recall), and executive function (Stroop Mixed, Trail Making B). These results were robust to analyses accounting for potential confounders, nonlinear effects of age, and exclusion of individuals with severe hearing loss. The reduction in cognitive performance associated with a 25 dB hearing loss was equivalent to the reduction associated with an age difference of 6.8 years. Hearing loss is independently associated with lower scores on tests of memory and executive function. Further research examining the longitudinal association of hearing loss with cognitive functioning is needed to confirm these cross-sectional findings.

Hearing Loss and Incident Dementia

Article

Full-text available

Feb 2011

To determine whether hearing loss is associated with incident all-cause dementia and Alzheimer disease (AD). Prospective study of 639 individuals who underwent audiometric testing and were dementia free in 1990 to 1994. Hearing loss was defined by a pure-tone average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear (normal, <25 dB [n = 455]; mild loss, 25-40 dB [n = 125]; moderate loss, 41-70 dB [n = 53]; and severe loss, >70 dB [n = 6]). Diagnosis of incident dementia was made by consensus diagnostic conference. Cox proportional hazards models were used to model time to incident dementia according to severity of hearing loss and were adjusted for age, sex, race, education, diabetes mellitus, smoking, and hypertension. Baltimore Longitudinal Study of Aging. Six hundred thirty-nine individuals aged 36 to 90 years. Incident cases of all-cause dementia and AD until May 31, 2008. During a median follow-up of 11.9 years, 58 cases of incident all-cause dementia were diagnosed, of which 37 cases were AD. The risk of incident all-cause dementia increased log linearly with the severity of baseline hearing loss (1.27 per 10-dB loss; 95% confidence interval, 1.06-1.50). Compared with normal hearing, the hazard ratio (95% confidence interval) for incident all-cause dementia was 1.89 (1.00-3.58) for mild hearing loss, 3.00 (1.43-6.30) for moderate hearing loss, and 4.94 (1.09-22.40) for severe hearing loss. The risk of incident AD also increased with baseline hearing loss (1.20 per 10 dB of hearing loss) but with a wider confidence interval (0.94-1.53). Hearing loss is independently associated with incident all-cause dementia. Whether hearing loss is a marker for early-stage dementia or is actually a modifiable risk factor for dementia deserves further study.

Remembering Can Cause Forgetting: Retrieval Dynamics in Long-Term Memory

Article

Full-text available

Oct 1994

Three studies show that the retrieval process itself causes long-lasting forgetting. Ss studied 8 categories (e.g., Fruit). Half the members of half the categories were then repeatedly practiced through retrieval tests (e.g., Fruit Or_____). Category-cued recall of unpracticed members of practiced categories was impaired on a delayed test. Experiments 2 and 3 identified 2 significant features of this retrieval-induced forgetting: The impairment remains when output interference is controlled, suggesting a retrieval-based suppression that endures for 20 min or more, and the impairment appears restricted to high-frequency members. Low-frequency members show little impairment, even in the presence of strong, practiced competitors that might be expected to block access to those items. These findings suggest a critical role for suppression in models of retrieval inhibition and implicate the retrieval process itself in everyday forgetting.

Lexical Familiarity and Processing Efficiency: Individual Differences in Naming, Lexical Decision, and Semantic Categorization

Article

Full-text available

Oct 1993

College students were separated into 2 groups (high and low) on the basis of 3 measures: subjective familiarity ratings of words, self-reported language experiences, and a test of vocabulary knowledge. Three experiments were conducted to determine if the groups also differed in visual word naming, lexical decision, and semantic categorization. High Ss were consistently faster than low Ss in naming visually presented words. They were also faster and more accurate in making difficult lexical decisions and in rejecting homophone foils in semantic categorization. Taken together, the results demonstrate that Ss who differ in lexical familiarity also differ in processing efficiency. The relationship between processing efficiency and working memory accounts of individual differences in language processing is also discussed.

Neurocognitive assessment of children with cochlear implants

Chapter

Jan 2016

“Mini-Mental State”. A practical method for grading the cognitive state of patients for the clinician

Book

Dec 1975
J PSYCHIATR RES

Mini-mental state-practical method for grading cognitive state of patients for clinicians

Article

Jan 1975
J PSYCHIATR RES

The Enigma of Poor Performance by Adults With Cochlear Implants

Article

Sep 2016
OTOL NEUROTOL

Objective: Considerable unexplained variability and large individual differences exist in speech recognition outcomes for postlingually deaf adults who use cochlear implants (CIs), and a sizeable fraction of CI users can be considered "poor performers." This article summarizes our current knowledge of poor CI performance, and provides suggestions to clinicians managing these patients. Method: Studies are reviewed pertaining to speech recognition variability in adults with hearing loss. Findings are augmented by recent studies in our laboratories examining outcomes in postlingually deaf adults with CIs. Results: In addition to conventional clinical predictors of CI performance (e.g., amount of residual hearing, duration of deafness), factors pertaining to both "bottom-up" auditory sensitivity to the spectro-temporal details of speech, and "top-down" linguistic knowledge and neurocognitive functions contribute to CI outcomes. Conclusions: The broad array of factors that contribute to speech recognition performance in adult CI users suggests the potential both for novel diagnostic assessment batteries to explain poor performance, and also new rehabilitation strategies for patients who exhibit poor outcomes. Moreover, this broad array of factors determining outcome performance suggests the need to treat individual CI patients using a personalized rehabilitation approach.

Neurocognitive factors in sensory restoration of early deafness: A connectome model

Article

Mar 2016
LANCET NEUROL

Progress in biomedical technology (cochlear, vestibular, and retinal implants) has led to remarkable success in neurosensory restoration, particularly in the auditory system. However, outcomes vary considerably, even after accounting for comorbidity—for example, after cochlear implantation, some deaf children develop spoken language skills approaching those of their hearing peers, whereas other children fail to do so. Here, we review evidence that auditory deprivation has widespread effects on brain development, affecting the capacity to process information beyond the auditory system. After sensory loss and deafness, the brain's effective connectivity is altered within the auditory system, between sensory systems, and between the auditory system and centres serving higher order neurocognitive functions. As a result, congenital sensory loss could be thought of as a connectome disease, with interindividual variability in the brain's adaptation to sensory loss underpinning much of the observed variation in outcome of cochlear implantation. Different executive functions, sequential processing, and concept formation are at particular risk in deaf children. A battery of clinical tests can allow early identification of neurocognitive risk factors. Intervention strategies that address these impairments with a personalised approach, taking interindividual variations into account, will further improve outcomes.

The Handbook of Speech Perception

Book

Jan 2008

The Handbook of Speech Perception is a collection of forward-looking articles that offer a summary of the technical and theoretical accomplishments in this vital area of research on language. Now available in paperback, this uniquely comprehensive companion brings together in one volume the latest research conducted in speech perception. Contains original contributions by leading researchers in the field. Illustrates technical and theoretical accomplishments and challenges across the field of research and language. Adds to a growing understanding of the far-reaching relevance of speech perception in the fields of phonetics, audiology and speech science, cognitive science, experimental psychology, behavioral neuroscience, computer science, and electrical engineering, among others.

Early Bimodal Stimulation Benefits Language Acquisition for Children With Cochlear Implants

Article

Nov 2015

Hypothesis: Adding a low-frequency acoustic signal to the cochlear implant (CI) signal (i.e., bimodal stimulation) for a period of time early in life improves language acquisition. Background: Children must acquire sensitivity to the phonemic units of language to develop most language-related skills, including expressive vocabulary, working memory, and reading. Acquiring sensitivity to phonemic structure depends largely on having refined spectral (frequency) representations available in the signal, which does not happen with CIs alone. Combining the low-frequency acoustic signal available through hearing aids with the CI signal can enhance signal quality. A period with this bimodal stimulation has been shown to improve language skills in very young children. This study examined whether these benefits persist into childhood. Methods: Data were examined for 48 children with CIs implanted under age 3 years, participating in a longitudinal study. All children wore hearing aids before receiving a CI, but upon receiving a first CI, 24 children had at least 1 year of bimodal stimulation (Bimodal group), and 24 children had only electric stimulation subsequent to implantation (CI-only group). Measures of phonemic awareness were obtained at second and fourth grades, along with measures of expressive vocabulary, working memory, and reading. Results: Children in the Bimodal group generally performed better on measures of phonemic awareness, and that advantage was reflected in other language measures. Conclusions: Having even a brief period of time early in life with combined electric-acoustic input provides benefits to language learning into childhood, likely because of the enhancement in spectral representations provided.

Executive Function, Cognitive Control, and Sequence Learning in Deaf Children with Cochlear Implants

Article

Jan 2012

Clinical research on deaf children with cochlear implants has been intellectually isolated from the mainstream of current research and theory in neuroscience, cognitive psychology, and developmental neuropsychology. As a consequence, the major clinical research problems have been narrowly focused on studies of speech and language outcomes and the efficacy of cochlear implantation as a medical treatment for profound hearing loss. As noted in both of the National Institutes of Health (NIH) consensus statements on cochlear implants in 1988 and 1995 (NIDCD, 1988, 1995), little, if any, research has investigated the underlying psychological and neurocognitive factors that are responsible for the enormous individual differences and variability in the effectiveness of cochlear implants. In this chapter, we report some new research findings on executive function, sequence memory, and cognitive control in prelingually deaf children who have received cochlear implants. Our results demonstrate that several domain-general neurocognitive processes related to executive function and cognitive control processes, such as working memory capacity, fluency-speed, inhibition, and organization-integration sequencing skills, are strongly associated with traditional clinical speech and language outcome measures. These specific neurocognitive processes reflect the global coordination, integration, and functional connectivity of multiple underlying brain systems used in speech perception, production, and spoken language processing. We argue that these executive function and organization-integration processes contribute an additional unique source of variance to speech and language outcomes above and beyond the conventional demographic, medical, and educational factors. Understanding the neurocognitive processes responsible for variability in spoken language processing will help both clinicians and researchers explain and predict individual differences in speech and language outcomes following cochlear implantation. Moreover, our results also have direct application to improving the diagnosis, treatment, and early identification of young deaf children who may be at high risk for poor outcomes following cochlear implantation.

Word Recognition Variability With Cochlear Implants: "Perceptual Attention" Versus "Auditory Sensitivity"

Article

Aug 2015
Ear Hear

Cochlear implantation does not automatically result in robust spoken language understanding for postlingually deafened adults. Enormous outcome variability exists, related to the complexity of understanding spoken language through cochlear implants (CIs), which deliver degraded speech representations. This investigation examined variability in word recognition as explained by "perceptual attention" and "auditory sensitivity" to acoustic cues underlying speech perception. Thirty postlingually deafened adults with CIs and 20 age-matched controls with normal hearing (NH) were tested. Participants underwent assessment of word recognition in quiet and perceptual attention (cue-weighting strategies) based on labeling tasks for two phonemic contrasts: (1) "cop"-"cob," based on a duration cue (easily accessible through CIs) or a dynamic spectral cue (less accessible through CIs), and (2) "sa"-"sha," based on static or dynamic spectral cues (both potentially poorly accessible through CIs). Participants were also assessed for auditory sensitivity to the speech cues underlying those labeling decisions. Word recognition varied widely among CI users (20 to 96%), but it was generally poorer than for NH participants. Implant users and NH controls showed similar perceptual attention and auditory sensitivity to the duration cue, while CI users showed poorer attention and sensitivity to all spectral cues. Both attention and sensitivity to spectral cues predicted variability in word recognition. For CI users, both perceptual attention and auditory sensitivity are important in word recognition. Efforts should be made to better represent spectral cues through implants, while also facilitating attention to these cues through auditory training.

LEXICAL FAMILIARITY AND PROCESSING EFFICIENCY - INDIVIDUAL-DIFFERENCES IN NAMING, LEXICAL DECISION, AND SEMANTIC CATEGORIZATION

Article

Sep 1993

Non-native Listeners’ Recognition of High-Variability Speech Using PRESTO

Article

Oct 2014

Natural variability in speech is a significant challenge to robust successful spoken word recognition. In everyday listening environments, listeners must quickly adapt and adjust to multiple sources of variability in both the signal and listening environments. High-variability speech may be particularly difficult to understand for non-native listeners, who have less experience with the second language (L2) phonological system and less detailed knowledge of sociolinguistic variation of the L2. The purpose of this study was to investigate the effects of high-variability sentences on non-native speech recognition and to explore the underlying sources of individual differences in speech recognition abilities of non-native listeners. Participants completed two sentence recognition tasks involving high-variability and low-variability sentences. They also completed a battery of behavioral tasks and self-report questionnaires designed to assess their indexical processing skills, vocabulary knowledge, and several core neurocognitive abilities. Native speakers of Mandarin (n = 25) living in the United States recruited from the Indiana University community participated in the current study. A native comparison group consisted of scores obtained from native speakers of English (n = 21) in the Indiana University community taken from an earlier study. Speech recognition in high-variability listening conditions was assessed with a sentence recognition task using sentences from PRESTO (Perceptually Robust English Sentence Test Open-Set) mixed in 6-talker multitalker babble. Speech recognition in low-variability listening conditions was assessed using sentences from HINT (Hearing In Noise Test) mixed in 6-talker multitalker babble. Indexical processing skills were measured using a talker discrimination task, a gender discrimination task, and a forced-choice regional dialect categorization task. Vocabulary knowledge was assessed with the WordFam word familiarity test, and executive functioning was assessed with the BRIEF-A (Behavioral Rating Inventory of Executive Function - Adult Version) self-report questionnaire. Scores from the non-native listeners on behavioral tasks and self-report questionnaires were compared with scores obtained from native listeners tested in a previous study and were examined for individual differences. Non-native keyword recognition scores were significantly lower on PRESTO sentences than on HINT sentences. Non-native listeners' keyword recognition scores were also lower than native listeners' scores on both sentence recognition tasks. Differences in performance on the sentence recognition tasks between non-native and native listeners were larger on PRESTO than on HINT, although group differences varied by signal-to-noise ratio. The non-native and native groups also differed in the ability to categorize talkers by region of origin and in vocabulary knowledge. Individual non-native word recognition accuracy on PRESTO sentences in multitalker babble at more favorable signal-to-noise ratios was found to be related to several BRIEF-A subscales and composite scores. However, non-native performance on PRESTO was not related to regional dialect categorization, talker and gender discrimination, or vocabulary knowledge. High-variability sentences in multitalker babble were particularly challenging for non-native listeners. Difficulty under high-variability testing conditions was related to lack of experience with the L2, especially L2 sociolinguistic information, compared with native listeners. Individual differences among the non-native listeners were related to weaknesses in core neurocognitive abilities affecting behavioral control in everyday life. American Academy of Audiology.

Speech: a Special Code

Book

Jan 1996

A M Liberman

Manual for Raven's Progressive Matrices and Vocabulary Scales: The Mill Hill Vocabulary Scale

Book

Jan 1998

Cognitive models of speech processing: psycholinguistics and computational perspectives

Article

Nov 1989
AI MAG

Gerry T M Altmann

Some Factors Underlying Individual Differences in Speech Recognition on PRESTO: A First Report

Article

Jul 2013

Background: Previous studies investigating speech recognition in adverse listening conditions have found extensive variability among individual listeners. However, little is currently known about the core underlying factors that influence speech recognition abilities. Purpose: To investigate sensory, perceptual, and neurocognitive differences between good and poor listeners on the Perceptually Robust English Sentence Test Open-set (PRESTO), a new high-variability sentence recognition test under adverse listening conditions. Research design: Participants who fell in the upper quartile (HiPRESTO listeners) or lower quartile (LoPRESTO listeners) on key word recognition on sentences from PRESTO in multitalker babble completed a battery of behavioral tasks and self-report questionnaires designed to investigate real-world hearing difficulties, indexical processing skills, and neurocognitive abilities. Study sample: Young, normal-hearing adults (N = 40) from the Indiana University community participated in the current study. Data collection and analysis: Participants' assessment of their own real-world hearing difficulties was measured with a self-report questionnaire on situational hearing and hearing health history. Indexical processing skills were assessed using a talker discrimination task, a gender discrimination task, and a forced-choice regional dialect categorization task. Neurocognitive abilities were measured with the Auditory Digit Span Forward (verbal short-term memory) and Digit Span Backward (verbal working memory) tests, the Stroop Color and Word Test (attention/inhibition), the WordFam word familiarity test (vocabulary size), the Behavioral Rating Inventory of Executive Function-Adult Version (BRIEF-A) self-report questionnaire on executive function, and two performance subtests of the Wechsler Abbreviated Scale of Intelligence (WASI) Performance Intelligence Quotient (IQ; nonverbal intelligence). Scores on self-report questionnaires and behavioral tasks were tallied and analyzed by listener group (HiPRESTO and LoPRESTO). Results: The extreme groups did not differ overall on self-reported hearing difficulties in real-world listening environments. However, an item-by-item analysis of questions revealed that LoPRESTO listeners reported significantly greater difficulty understanding speakers in a public place. HiPRESTO listeners were significantly more accurate than LoPRESTO listeners at gender discrimination and regional dialect categorization, but they did not differ on talker discrimination accuracy or response time, or gender discrimination response time. HiPRESTO listeners also had longer forward and backward digit spans, higher word familiarity ratings on the WordFam test, and lower (better) scores for three individual items on the BRIEF-A questionnaire related to cognitive load. The two groups did not differ on the Stroop Color and Word Test or either of the WASI performance IQ subtests. Conclusions: HiPRESTO listeners and LoPRESTO listeners differed in indexical processing abilities, short-term and working memory capacity, vocabulary size, and some domains of executive functioning. These findings suggest that individual differences in the ability to encode and maintain highly detailed episodic information in speech may underlie the variability observed in speech recognition performance in adverse listening conditions using high-variability PRESTO sentences in multitalker babble.

Speech recognition in adverse conditions: A review

Article

Sep 2012

This article presents a review of the effects of adverse conditions (ACs) on the perceptual, linguistic, cognitive, and neurophysiological mechanisms underlying speech recognition. The review starts with a classification of ACs based on their origin: Degradation at the source (production of a noncanonical signal), degradation during signal transmission (interfering signal or medium-induced impoverishment of the target signal), receiver limitations (peripheral, linguistic, cognitive). This is followed by a parallel, yet orthogonal classification of ACs based on the locus of their effect: Perceptual processes, mental representations, attention, and memory functions. We then review the added value that ACs provide for theories of speech recognition, with a focus on fundamental themes in psycholinguistics: Content and format of lexical representations, time-course of lexical access, word segmentation, feed-back in speech perception and recognition, lexical-semantic integration, interface between the speech system and general cognition, neuroanatomical organisation of speech processing. We conclude by advocating an approach to speech recognition that includes rather than neutralises complex listening environments and individual differences.

California Verbal Learning Test–II

Article

Jan 2000

Technological, Biological, and Acoustical Constraints to Music Perception in Cochlear Implant Users.

Article

May 2013

Despite advances in technology, the ability to perceive music remains limited for many cochlear implant users. This paper reviews the technological, biological, and acoustical constraints that make music an especially challenging stimulus for cochlear implant users, while highlighting recent research efforts to overcome these shortcomings. The limitations of cochlear implant devices, which have been optimized for speech comprehension, become evident when applied to music, particularly with regards to inadequate spectral, fine-temporal, and dynamic range representation. Beyond the impoverished information transmitted by the device itself, both peripheral and central auditory nervous system deficits are seen in the presence of sensorineural hearing loss, such as auditory nerve degeneration and abnormal auditory cortex activation. These technological and biological constraints to effective music perception are further compounded by the complexity of the acoustical features of music itself that require the perceptual integration of varying rhythmic, melodic, harmonic, and timbral elements of sound. Cochlear implant users not only have difficulty perceiving spectral components individually (leading to fundamental disruptions in perception of pitch, melody, and harmony) but also display deficits with higher perceptual integration tasks required for music perception, such as auditory stream segregation. Despite these current limitations, focused musical training programs, new assessment methods, and improvements in the representation and transmission of the complex acoustical features of music through technological innovation offer the potential for significant advancements in cochlear implant-mediated music perception.

Improving Speech Perception in Noise with Current Focusing in Cochlear Implant Users

Article

Mar 2013

Factors Affecting Open-Set Word Recognition in Adults With Cochlear Implants

Article

Jan 2013
Ear Hear

Objective: A great deal of variability exists in the speech-recognition abilities of postlingually deaf adult cochlear implant (CI) recipients. A number of previous studies have shown that duration of deafness is a primary factor affecting CI outcomes; however, there is little agreement regarding other factors that may affect performance. The objective of the present study was to determine the source of variability in CI outcomes by examining three main factors, biographic/audiologic information, electrode position within the cochlea, and cognitive abilities in a group of newly implanted CI recipients. Design: Participants were 114 postlingually deaf adults with either the Cochlear or Advanced Bionics CI systems. Biographic/audiologic information, aided sentence-recognition scores, a high resolution temporal bone CT scan and cognitive measures were obtained before implantation. Monosyllabic word recognition scores were obtained during numerous test intervals from 2 weeks to 2 years after initial activation of the CI. Electrode position within the cochlea was determined by three-dimensional reconstruction of pre- and postimplant CT scans. Participants' word scores over 2 years were fit with a logistic curve to predict word score as a function of time and to highlight 4-word recognition metrics (CNC initial score, CNC final score, rise time to 90% of CNC final score, and CNC difference score). Results: Participants were divided into six outcome groups based on the percentile ranking of their CNC final score, that is, participants in the bottom 10% were in group 1; those in the top 10% were in group 6. Across outcome groups, significant relationships from low to high performance were identified. Biographic/audiologic factors of age at implantation, duration of hearing loss, duration of hearing aid use, and duration of severe-to-profound hearing loss were significantly and inversely related to performance as were frequency modulated tone, sound-field threshold levels obtained with the CI. That is, the higher-performing outcome groups were younger in age at the time of implantation, had shorter duration of severe-to-profound hearing loss, and had lower CI sound-field threshold levels. Significant inverse relationships across outcome groups were also observed for electrode position, specifically the percentage of electrodes in scala vestibuli as opposed to scala tympani and depth of insertion of the electrode array. In addition, positioning of electrode arrays closer to the modiolar wall was positively correlated with outcome. Cognitive ability was significantly and positively related to outcome; however, age at implantation and cognition were highly correlated. After controlling for age, cognition was no longer a factor affecting outcomes. Conclusion: There are a number of factors that limit CI outcomes. They can act singularly or collectively to restrict an individual's performance and to varying degrees. The highest performing CI recipients are those with the least number of limiting factors. Knowledge of when and how these factors affect performance can favorably influence counseling, device fitting, and rehabilitation for individual patients and can contribute to improved device design and application.

Human Memory: A Proposed System and its Control Processes

Article

Dec 1968
Psychol Learn Motiv

Parent Word Familiarity and the Language Development of Pediatric Cochlear Implant Users

Article

Jan 2000

Linguistic environment is one unexplored factor that may influence language development in pediatric cochlear implant users. This study examines the relationship between parent word familiarity and the language development of pediatric cochlear implant users. Participants and their parents were recruited from an ongoing study at the Indiam University School of Medicine to examine benefits of pediatric cochlear implant use. Thirty-two parent participants rated their familiarity with 150 words. These ratings were compared with children's scores on standardized measures. Pearson product-moment correlation coefficients indicated a significant relationship between parent word familiarity ratings and children's receptive vocabulary and language abilities as well as with their expressive language abilities. Analyses of covariance (ANCOVAs), adjusting for communication mode and speech perception, confirmed these effects, revealing significant relationships between parent word familiarity ratings and children's receptive vocabulary and language abilities. This link between parent ratings and children's abilities provides evidence of the importance of a rich linguistic environment.

Development, Reliability, and Validity of PRESTO: A New High-Variability Sentence Recognition Test

Article

Jan 2013

Background: There is a pressing need for new clinically feasible speech recognition tests that are theoretically motivated, sensitive to individual differences, and access the core perceptual and neurocognitive processes used in speech perception. PRESTO (Perceptually Robust English Sentence Test Open-set) is a new high-variability sentence test designed to reflect current theories of exemplar-based learning, attention, and perception, including lexical organization and automatic encoding of indexical attributes. Using sentences selected from the TIMIT (Texas Instruments/Massachusetts Institute of Technology) speech corpus, PRESTO was developed to include talker and dialect variability. The test consists of lists balanced for talker gender, keywords, frequency, and familiarity. Purpose: To investigate the performance, reliability, and validity of PRESTO. Research design: In Phase I, PRESTO sentences were presented in multitalker babble at four signal-to-noise ratios (SNRs) to obtain a distribution of performance. In Phase II, participants returned and were tested on new PRESTO sentences and on HINT (Hearing In Noise Test) sentences presented in multitalker babble. Study sample: Young, normal-hearing adults (N = 121) were recruited from the Indiana University community for Phase I. Participants who scored within the upper and lower quartiles of performance in Phase I were asked to return for Phase II (N = 40). Data collection and analysis: In both Phase I and Phase II, participants listened to sentences presented diotically through headphones while seated in enclosed carrels at the Speech Research Laboratory at Indiana University. They were instructed to type in the sentence that they heard using keyboards interfaced to a computer. Scoring for keywords was completed offline following data collection. Phase I data were analyzed by determining the distribution of performance on PRESTO at each SNR and at the average performance across all SNRs. PRESTO reliability was analyzed by a correlational analysis of participant performance at test (Phase I) and retest (Phase II). PRESTO validity was analyzed by a correlational analysis of participant performance on PRESTO and HINT sentences tested in Phase II, and by an analysis of variance of within-subject factors of sentence test and SNR, and a between-subjects factor of group, based on level of Phase I performance. Results: A wide range of performance on PRESTO was observed; averaged across all SNRs, keyword accuracy ranged from 40.26 to 76.18% correct. PRESTO accuracy at retest (Phase II) was highly correlated with Phase I accuracy (r = 0.92, p < 0.001). PRESTO scores were also correlated with scores on HINT sentences (r = 0.52, p < 0.001). Phase II results showed an interaction between sentence test type and SNR [F(3, 114) = 121.36, p < 0.001], with better performance on HINT sentences at more favorable SNRs and better performance on PRESTO sentences at poorer SNRs. Conclusions: PRESTO demonstrated excellent test/retest reliability. Although a moderate correlation was observed between PRESTO and HINT sentences, a different pattern of results occurred with the two types of sentences depending on the level of the competition, suggesting the use of different processing strategies. Findings from this study demonstrate the importance of high-variability materials for assessing and understanding individual differences in speech perception.

Encoding categories of words: An empirical approach to meaning

Article

Delos D. Wickens

Presents a series of studies investigating the dimension along which words are encoded, using the "release from proactive inhibition" in short-term memory technique. Results indicate that semantic dimensions (taxonomic categories or semantic differential) are highly effective, whereas physical characteristics, i.e., word length or figure-ground colors of the slide presentation are relatively ineffective in releasing proactive inhibition. Results of this technique of measuring encoding are related to other types of experiments on verbal material as well as to the topic of subception and imageless thought. (36 ref.) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Wide‐Range Assessment of Memory and Learning

Chapter

Jan 2010

Wayne V. Adams

Memory is one of the central ingredients in determining who we are and become. Without it, we would struggle to make sense of the present and would have no past or future. And yet, while so critical, memory is an extremely vulnerable cognitive system, and therefore its evaluation is especially important following acute or progressive insults to the brain, such as those resulting from motor vehicle accidents, blast injuries, multiple sclerosis, brain tumors, infections, and strokes. Memory also normally exhibits measurable differences within and across the age range, with the greatest variability seen in younger children and older adults. The Wide Range Assessment of Memory and Learning, second edition (WRAML2), is an individually administered test battery designed to assess memory ability across the age range (5 to 90 years). Consequently, the battery can prove useful in assessment settings often found in hospitals, schools, rehabilitation centers, and neuropsychologists' offices. Keywords: memory; assessment; WRAML2

The story of the two-store model: Past criticisms, current status, and future directions

Chapter

Jan 1993

Jeroen GW Raaijmakers

This occasion not only marks the twenty-fifth anniversary of the Attention and Performance series but also the silver jubilee of the two-store model (Atkinson & Shiffrin, 1965, 1968). The treatment of this model in textbooks on memory suggests that it has serious deficiencies. However, this assessment is quite wrong, and the two- store model is in fact capable of handling the findings that supposedly reject it. The SAM model (Raaijmakers & Shiffrin, 1981) developed out of the two-store model and might be viewed as a contemporary version of the two-store model. A general overview is given of how this model accounts for a variety of memory phenomena. Recently, the SAM model has been modified to include a process of contextual fluctuation. This process has proven useful in applications of the SAM model to interference and forgetting phenomena. New research is discussed that extends these applications to spacing and repetition phenomena.

Speech Perception in Deaf Children with Cochlear Implants

Chapter

Jan 2008

David B Pisoni

Although a cochlear implant (CI) restores access to sound and speech for profoundly deaf children, there is substantial inter-individual variation in outcomes and many children with a CI continue to be delayed in their spoken language development. This suggests that they may benefit from alternative modes of communication such as sign language. However, the role of signed input in the education of children with a CI is much debated. The aim of the present thesis was two-folded: to explore underlying processes in speech perception that may help to explain inter-individual variation in outcomes, and to obtain insight into the effects of signed input on spoken language abilities. To that end, this thesis investigates speech and sign perception in 5- to 6-year old children with a CI. More specifically, it examines and interrelates the use of acoustic and visual cues in phonetic categorization and the representation of phonetic contrasts in novel words and signs. Additionally, it investigates the effects of bimodal (i.e., simultaneously spoken and signed) input on speech perception. The analyses show that children with a CI have fuzzy boundaries between sound categories and have difficulties to represent phonetic detail in novel words. Weakly-specified auditory phonological-lexical representations likely negatively impact speech processing. Importantly, signing experience did not negatively affect their speech perception and bimodal input seemed to even facilitate spoken word recognition. Together, these findings form an argument for bilingualism in a spoken and a signed language as the ultimate goal in the rehabilitation and education of children with a CI.

Proactive inhibition and item similarity in short-term memory

Article

Dec 1963

The experiment investigated the effect of proactive inhibition in short-term retention as a function of degree of similarity between the proactive items and the critical test items. When the same class of material, CCC's or NNN's, was used for proactive and test items, marked interference was obtained with as few as three proactive items. No evidence for proactive inhibition was found when the proactive and test items were drawn from different classes of materials, CCC to NNN, or vice versa. There was no evidence that formal similarity (same units in proactive items as in test items) produced greater interference than that obtained from proactive items lacking this formal similarity, but the failure to find any difference may have arisen from the large amount of interference already present.

Rehearsal processes in free recall: A procedure for direct observation

Article

Feb 1970

Rehearsal during the presentation of free-recall lists was made observable by having Ss rehearse aloud as items were shown for study and tape recording their output. Items studied early in the list were found to receive more rehearsal than other list items; probability of recall for individual items was found to be an increasing function of amount of rehearsal; items being rehearsed immediately prior to test were recalled with high probability. A U-shaped serial-position curve was found. It is suggested that the recency effects may be attributed to the high probability of recall observed for items rehearsed just prior to test, while the additional rehearsal accorded initial items of the list results in the primacy effect.

Hearing Loss in Older Adults

Article

Mar 2012
J Am Med Assoc

Frank R Lin

The manifestations of age-related hearing loss (ARHL) in many older adults are subtle1—having to increase the volume of the television, missing words of a conversation—and hence, hearing loss is often perceived as an unfortunate but inconsequential part of aging. This observation is borne out by the epidemiologic data, which report that although 26.7 million US adults aged 50 years or older have a clinically significant hearing loss, fewer than 15% use hearing aids.2

Long-Term Performance of Cochlear Implants in Postlingually Deafened Adults

Article

Feb 2012
OTOLARYNG HEAD NECK

To evaluate the stability of long-term hearing performance after cochlear implantation (CI) in postlingually deafened adults and to explore the boundaries and limitations of the present test batteries for adult CI patients. Case series with chart review. Tertiary referral center. A cohort of 1005 postlingually deafened adult cochlear implantees, who received their implants after age 18 years, was unilaterally implanted and had no inner ear malformations or cochlear ossification. Hearing performance with cochlear implant was evaluated with the help of 5 standard German speech tests. The average performance improved significantly during the first 6 months in all tests (learning phase) and afterward entered a plateau phase in which no statistically significant improvements or deteriorations were observed for more than 20 years of follow-up. For each test, the average performance of the cohort, the ceiling effect, and the average results for high and low performers are presented. In this study, postlingually deafened adults required about 6 months to learn how to process the artificial signals delivered by the cochlear implant. After this learning phase, the hearing performance entered a stable plateau phase for more than 20 years. This stability reveals the long-term reliability of the technology and the biological stability of the electrode-nerve interface over years. In this study, the authors also evaluated the "ceiling effect" with 5 standard German speech tests, used for evaluation of postlingually deafened adult CI patients.

Cochlear implants. Matching the prosthesis to the brain and facilitating desired plastic changes in brain function

Article

Dec 2011

The cochlear implant (CI) is one of the great success stories of modern medicine. A high level of function is provided for most patients. However, some patients still do not achieve excellent or even good results using the present-day devices. Accumulating evidence is pointing to differences in the processing abilities of the "auditory brain" among patients as a principal contributor to this remaining and still large variability in outcomes. In this chapter, we describe a new approach to the design of CIs that takes these differences into account and thereby may improve outcomes for patients with compromised auditory brains.

Hearing Loss and Cognition Among Older Adults in the United States

Article

Jul 2011
J GERONTOL A-BIOL

Frank R Lin

To investigate the association between hearing loss and cognitive function in a nationally representative sample of older adults. We analyzed data from the 1999 to 2002 cycles of the National Health and Nutritional Examination Survey during which participants aged 60-69 years (n = 605) underwent both audiometric and cognitive testing. Hearing loss was defined by a pure tone average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better hearing ear. Cognitive testing consisted of the Digit Symbol Substitution Test (DSST), a nonverbal test that assesses executive function and psychomotor processing. Data on hearing aid use, demographics, and medical history were obtained from interviews. Regression models were used to examine the association between hearing loss and cognition while adjusting for confounders. Analyses incorporated sampling weights to yield results that are generalizable to the U.S. population. Greater hearing loss was significantly associated with lower scores on the DSST after adjustment for demographic factors and medical history (DSST score difference of -1.5 [95% confidence interval: -2.9 to -0.23] per 10 dB of hearing loss). Hearing aid use was positively associated with cognitive functioning (DSST score difference of 7.4 [95% confidence interval: -0.62 to 15.4]). The reduction in cognitive performance associated with a 25 dB hearing loss was equivalent to the reduction associated with an age difference of 7 years. Hearing loss is independently associated with lower scores on the DSST. Further research is needed to determine whether hearing loss is a modifiable risk factor or an early marker of cognitive decline.

Perception of Environmental Sounds by Experienced Cochlear Implant Patients

Article

Jul 2011
Ear Hear

Verbal Learning and Memory After Cochlear Implantation in Postlingually Deaf Adults: Some New Findings with the CVLT-II

Abstract

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