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Kallioinen P, Olofsson JK, von Mentzer CN. Semantic processing in children with Cochlear Implants: A review of current N400 studies and recommendations for future research. Biol Psychol 2023; 182:108655. [PMID: 37541539 DOI: 10.1016/j.biopsycho.2023.108655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Deaf and hard of hearing children with cochlear implants (CI) often display impaired spoken language skills. While a large number of studies investigated brain responses to sounds in this population, relatively few focused on semantic processing. Here we summarize and discuss findings in four studies of the N400, a cortical response that reflects semantic processing, in children with CI. A study with auditory target stimuli found N400 effects at delayed latencies at 12 months after implantation, but at 18 and 24 months after implantation effects had typical latencies. In studies with visual target stimuli N400 effects were larger than or similar to controls in children with CI, despite lower semantic abilities. We propose that in children with CI, the observed large N400 effect reflects a stronger reliance on top-down predictions, relative to bottom-up language processing. Recent behavioral studies of children and adults with CI suggest that top-down processing is a common compensatory strategy, but with distinct limitations such as being effortful. A majority of the studies have small sample sizes (N < 20), and only responses to image targets were studied repeatedly in similar paradigms. This precludes strong conclusions. We give suggestions for future research and ways to overcome the scarcity of participants, including extending research to children with conventional hearing aids, an understudied group.
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Affiliation(s)
- Petter Kallioinen
- Department of Linguistics, Stockholm University, Stockholm, Sweden; Lund University Cognitive Science, Lund University, Lund, Sweden.
| | - Jonas K Olofsson
- Department of Psychology, Stockholm University, Stockholm, Sweden
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Huang W, Wong LLN, Chen F. Pre-attentive fundamental frequency processing in Mandarin-speaking children with cochlear implants as revealed by the peak latency of positive mismatch response. Front Neurosci 2022; 16:1045939. [PMID: 36570825 PMCID: PMC9773377 DOI: 10.3389/fnins.2022.1045939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
Introduction Fundamental frequency (F0) serves as the primary acoustic cue for Mandarin tone perception. Recent behavioral studies suggest that F0 information may be differently processed between Mandarin-speaking normal-hearing (NH) children and children with cochlear implants (CIs), which may partially explain the unsatisfactory outcome of lexical tone recognition using CIs with tonal language-oriented speech processing strategies. The aim of the current study was to provide neural evidence of F0 processing in Mandarin-speaking kindergarten-aged children with CIs compared with NH children. Methods Positive mismatch responses (p-MMRs) to the change of the two acoustic dimensions of F0 (F0 contour and F0 level) in Mandarin-speaking kindergarten-aged children with CIs (n = 19) and their age-matched NH peers (n = 21). Results The two groups of children did not show any significant difference on the mean amplitude of p-MMR to either F0 contour or F0 level change. While the CI group exhibited a significantly shorter peak latency of p-MMR to F0 contour change than to F0 level change, an opposite pattern was observed in the NH group. Discussion This study revealed a higher sensitivity to F0 contour change than to F0 level change in children with CIs, which was different from that in NH children. The neural evidence of discrepant F0 processing between children with CIs and NH children in this study was consistent with the previously reported behavioral findings and may serve as a reference for the development and improvement of tonal language-oriented speech processing strategies.
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Affiliation(s)
- Wanting Huang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Lena L. N. Wong
- Unit of Human Communication, Development, and Information Sciences, Faculty of Education, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Fei Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, China,*Correspondence: Fei Chen,
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Torppa R, Kuuluvainen S, Lipsanen J. The development of cortical processing of speech differs between children with cochlear implants and normal hearing and changes with parental singing. Front Neurosci 2022; 16:976767. [PMID: 36507354 PMCID: PMC9731313 DOI: 10.3389/fnins.2022.976767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 11/04/2022] [Indexed: 11/21/2022] Open
Abstract
Objective The aim of the present study was to investigate speech processing development in children with normal hearing (NH) and cochlear implants (CI) groups using a multifeature event-related potential (ERP) paradigm. Singing is associated to enhanced attention and speech perception. Therefore, its connection to ERPs was investigated in the CI group. Methods The paradigm included five change types in a pseudoword: two easy- (duration, gap) and three difficult-to-detect (vowel, pitch, intensity) with CIs. The positive mismatch responses (pMMR), mismatch negativity (MMN), P3a and late differentiating negativity (LDN) responses of preschoolers (below 6 years 9 months) and schoolchildren (above 6 years 9 months) with NH or CIs at two time points (T1, T2) were investigated with Linear Mixed Modeling (LMM). For the CI group, the association of singing at home and ERP development was modeled with LMM. Results Overall, responses elicited by the easy- and difficult to detect changes differed between the CI and NH groups. Compared to the NH group, the CI group had smaller MMNs to vowel duration changes and gaps, larger P3a responses to gaps, and larger pMMRs and smaller LDNs to vowel identity changes. Preschoolers had smaller P3a responses and larger LDNs to gaps, and larger pMMRs to vowel identity changes than schoolchildren. In addition, the pMMRs to gaps increased from T1 to T2 in preschoolers. More parental singing in the CI group was associated with increasing pMMR and less parental singing with decreasing P3a amplitudes from T1 to T2. Conclusion The multifeature paradigm is suitable for assessing cortical speech processing development in children. In children with CIs, cortical discrimination is often reflected in pMMR and P3a responses, and in MMN and LDN responses in children with NH. Moreover, the cortical speech discrimination of children with CIs develops late, and over time and age, their speech sound change processing changes as does the processing of children with NH. Importantly, multisensory activities such as parental singing can lead to improvement in the discrimination and attention shifting toward speech changes in children with CIs. These novel results should be taken into account in future research and rehabilitation.
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Affiliation(s)
- Ritva Torppa
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland,Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland,Centre of Excellence in Music, Mind, Body and Brain, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Soila Kuuluvainen
- Cognitive Brain Research Unit, Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland,Department of Digital Humanities, Faculty of Arts, University of Helsinki, Helsinki, Finland
| | - Jari Lipsanen
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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Yang Y, Li Q, Xiao Y, Liu Y, Sun K, Li B, Zheng Q. Auditory Discrimination Elicited by Nonspeech and Speech Stimuli in Children With Congenital Hearing Loss. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2022; 65:3981-3995. [PMID: 36095326 PMCID: PMC9927627 DOI: 10.1044/2022_jslhr-22-00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/15/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE Congenital deafness not only delays auditory development but also hampers the ability to perceive nonspeech and speech signals. This study aimed to use auditory event-related potentials to explore the mismatch negativity (MMN), P3a, negative wave (Nc), and late discriminative negativity (LDN) components in children with and without hearing loss. METHOD Nineteen children with normal hearing (CNH) and 17 children with hearing loss (CHL) participated in this study. Two sets of pure tones (1 kHz vs. 1.1 kHz) and lexical tones (/ba2/ vs. /ba4/) were used to examine the auditory discrimination process. RESULTS MMN could be elicited by the pure tone and the lexical tone in both groups. The MMN latency elicited by nonspeech and speech was later in CHL than in CNH. Additionally, the MMN latency induced by speech occurred later in the left than in the right hemisphere in CNH, and the MMN amplitude elicited by speech in CHL produced a discriminative deficiency compared with that in CNH. Although the P3a latency and amplitude elicited by nonspeech in CHL and CNH were not significantly different, the Nc amplitude elicited by speech performed much lower in CHL than in CNH. Furthermore, the LDN latency elicited by nonspeech was later in CHL than in CNH, and the LDN amplitude induced by speech showed higher dominance in the right hemisphere in both CNH and CHL. CONCLUSION By incorporating nonspeech and speech auditory conditions, we propose using MMN, Nc, and LDN as potential indices to investigate auditory perception, memory, and discrimination.
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Affiliation(s)
- Ying Yang
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Qiong Li
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Yanan Xiao
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Yulu Liu
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Kangning Sun
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Bo Li
- Department of Hearing and Speech Rehabilitation, Binzhou Medical University, Yantai, China
| | - Qingyin Zheng
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH
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Ziatabar Ahmadi Z, Mahmoudian S, Ashayeri H. P-MMR and LDN beside MMN as Speech-evoked Neural Markers in Children with Cochlear Implants: A Review. Dev Neuropsychol 2021; 47:1-16. [PMID: 34927493 DOI: 10.1080/87565641.2021.2004601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This review mainly explores less-reported neural markers to speech-evoked contrasts in children with cochlear implants (CI). Databases and electronic journals were searched with keywords of "mismatch responses" AND "positive mismatch response" (p-MMR) AND "late discriminate negativity" (LDN). P-MMR likely is as a measurement of brain immaturity in CI children while the developmental trajectories of LDN remain unexplained in older CI children. In CI children, there is a p-MMR-MMN-LDN sequence to speech stimuli developmentally. Whereas these aforementioned neural responses anticipate developmental changes in CI groups, it is still uncertain about the cutoff age for disappearance of p-MMR and LDN.
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Affiliation(s)
- Zohreh Ziatabar Ahmadi
- Department of Speech Therapy, School of Rehabilitation, Babol University of Medical Sciences, Babol, Iran
| | - Saied Mahmoudian
- ENT and Head & Neck Research Center and Department, The Five Senses Health Institute, Iran University of Medical Sciences, Tehran, Iran.,Department of Otolaryngology, Medical University of Hannover (Mhh), Hannover, Germany
| | - Hassan Ashayeri
- Department of Basic Sciences in Rehabilitation, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
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Engström E, Kallioinen P, Nakeva von Mentzer C, Lindgren M, Sahlén B, Lyxell B, Ors M, Uhlén I. Auditory event-related potentials and mismatch negativity in children with hearing loss using hearing aids or cochlear implants - A three-year follow-up study. Int J Pediatr Otorhinolaryngol 2021; 140:110519. [PMID: 33268013 DOI: 10.1016/j.ijporl.2020.110519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/21/2020] [Accepted: 11/22/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVES The primary aim was to examine how event-related potentials (ERPs) and mismatch negativity (MMN) change and develop over time among children with hearing loss (HL) using hearing aids (HAs) or cochlear implants (CIs). Children with normal hearing (NH) were tested as a reference group. METHODS This three-year follow-up study included 13 children with sensorineural HL (SNHL); 7 children using bilateral HAs and 6 children using CIs; and 10 children with NH as a reference group. ERPs were recorded at baseline and after three years. At time for the original study the children were approximately 5-8 years old and at the follow-up study 8-11 years old. ERP recordings and data processing were identical in both sessions. A standard stimulus alternated with five different deviants (gap, intensity, pitch, location and duration), presented in a pseudorandom sequence, thus following the multi-feature paradigm, Optimum-1. MMN was calculated from the average ERP of each deviant minus the standard stimuli. Repeated measures ANOVA was used for the statistical analyses and the results were based on samples within a specific time interval; 80-224 ms. RESULTS There was a statistically significant difference in the obligatory responses between the NH and HA groups at baseline, but this difference disappeared after three years in our follow-up study. The children with HA also showed a significant difference in mean ERP at baseline compared to follow-up, and significant differences between the deviants at follow-up but not at baseline. This suggests an improvement over time among the children with HAs. On the other hand, the children with CIs did not differ from the NH children at baseline, but after three years their mean ERP was significantly lower compared to both the children with HA and NH, indicating a reduced development of the central auditory system in this age span among the children with CIs. Regarding MMN, there was an interaction between the duration deviant and time for the children with HA, also indicating a possible improvement over time among the HA children. CONCLUSIONS This three-year follow-up study shows neurophysiological differences between children with HL and children with NH. The results suggest a delay in the central auditory processing among the HA children compared to children with NH, but a possible catch-up, over time, and this potential may be worth to be utilized. Regarding the CI children, similar improvement in this age span is missing, meaning there are differences between the subgroups of children with HL, i.e. the children with HAs vs. CIs. The results highlight the importance of distinguishing between subgroups of children with HL in further research.
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Affiliation(s)
- Elisabet Engström
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77, Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86, Stockholm, Sweden.
| | - Petter Kallioinen
- Department of Linguistics, Stockholm University, 106 91, Stockholm, Sweden
| | | | - Magnus Lindgren
- Cognition, Communication & Learning, Lund University, 221 00, Lund, Sweden; Department of Psychology, Lund University, 221 00, Lund, Sweden
| | - Birgitta Sahlén
- Cognition, Communication & Learning, Lund University, 221 00, Lund, Sweden; Lund University, Faculty of Medicine, Department of Clinical Sciences, Logopedics, Phoniatrics & Audiology, Lasarettsgatan 21, 22185, Lund, Sweden
| | - Björn Lyxell
- Department of Behavioral Sciences and Learning, Swedish Institute for Disability Research, Linköping University, 581 83, Linköping, Sweden; Department of Special Needs Education, University of Oslo, Oslo, Norway
| | - Marianne Ors
- Department of Clinical Neurophysiology, Skåne University Hospit, 221 85, Lund, Sweden
| | - Inger Uhlén
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77, Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86, Stockholm, Sweden
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Engström E, Kallioinen P, Lindgren M, Nakeva von Mentzer C, Sahlén B, Lyxell B, Uhlén I. Computer-assisted reading intervention for children with hearing impairment using cochlear implants: Effects on auditory event-related potentials and mismatch negativity. Int J Pediatr Otorhinolaryngol 2020; 137:110229. [PMID: 32896345 DOI: 10.1016/j.ijporl.2020.110229] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES The primary aim was to find out whether a computer-assisted reading intervention program with a phonic approach can affect event-related (ERPs) and mismatch negativity (MMN) in hearing impaired (HI) children using cochlear implants (CIs). METHODS This study involved a test group of 15 HI children with CIs and a control group of 14 normal hearing (NH) children. The children were 4 years and 10 months to 8 years and 1 month old. ERPs were recorded immediately before and after 4 weeks of training with a computer-assisted reading intervention, GraphoGame. A multi-feature paradigm, Optimum-1, was used, i.e. a standard stimulus alternated with five different deviants: gap intensity, pitch, location and duration. MMN was calculated from the mean amplitude ERP of each deviant minus the standard stimulus response in a specific time interval, 80 - 224 ms. Repeated measures ANOVA was used for the statistical analysis. RESULTS The results did not show any significant changes with the computerassisted training in the ERPs and MMNs among the HI children with CIs. The presence of both MMN and a positive mismatch response (pMMR), which might reflect an immaturity, complicates interpreting the results in this age group. Individually, there was a mix of MMNs and pMMRs among all participants, pre and post training, and the change of each deviant after intervention was not predictable. CONCLUSIONS There are no significant changes in ERP or MMN after intervention, however lack of significances must be interpreted with caution. Besides the presence of both MMNs and pMMRs, only modest changes are to be expected on an individual basis and small samples hinder making statistical conclusions regarding the training's effects. The study contributes to some more descriptive pieces of ERPs and MMNs among the HI children with CIs. The issues of MMN and pMMR are highlighted.
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Affiliation(s)
- Elisabet Engström
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77, Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86, Stockholm, Sweden.
| | - Petter Kallioinen
- Department of Linguistics, Stockholm University, 106 91, Stockholm, Sweden.
| | - Magnus Lindgren
- Department of Psychology, Lund University, 221 00, Lund, Sweden; Cognition, Communication & Learning, Lund University, 221 00, Lund, Sweden.
| | | | - Birgitta Sahlén
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Logopedics, Phoniatrics & Audiology, Lasarettsgatan 21, 22185, Lund, Sweden; Cognition, Communication & Learning, Lund University, 221 00, Lund, Sweden.
| | - Björn Lyxell
- Department of Behavorial Sciences and Learning, Swedish Institute for Disability Research, Linköping University, 581 83, Linköping, Sweden; Department of Special Needs Education, University of Oslo, Oslo, Norway.
| | - Inger Uhlén
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77, Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86, Stockholm, Sweden.
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Engström E, Kallioinen P, Nakeva von Mentzer C, Lindgren M, Ors M, Sahlén B, Lyxell B, Uhlén I. Computer-assisted reading intervention for children with sensorineural hearing loss using hearing aids: Effects on auditory event-related potentials and mismatch negativity. Int J Pediatr Otorhinolaryngol 2019; 117:17-25. [PMID: 30579075 DOI: 10.1016/j.ijporl.2018.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/27/2018] [Accepted: 11/02/2018] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The primary aim was to investigate whether computer-assisted reading intervention somehow can affect event-related potentials (ERP) and mismatch negativity (MMN) in hearing impaired (HI) children with hearing aids (HAs) and normal hearing (NH) children. METHODS The study included 15 HI children with sensorineural hearing loss (SNHL) using bilateral HAs and 14 NH children as a reference group; all children between the ages of 5 and 8. A multi-feature MMN-paradigm, Optimum-1, with a standard stimulus alternating with 5 different deviants was used. ERPs were recorded pre and post intervention, i.e. one month of repeatedly computer-assisted training (GraphoGame). MMN was calculated from the average ERP of each deviant minus standard. Data were based on samples within a specific time interval, 80-224 ms, and repeated measures ANOVA was used to analyze possible interactions. RESULTS There was a significant difference between groups before training, though, the mean obligatory responses or MMN was not statistically significantly different before versus after training, neither among the NH nor the HI children. Further, the HI children did generally achieve lower levels in GraphoGame compared to the NH children. Altogether, our findings indicate differences between the groups and that training may affect the neurophysiological processing in the brain, gaining the HI children. Both MMN and positive mismatch response (pMMR) were seen among both the HA and NH children, irrespective to deviant type. Individually, changes of the MMN and pMMR after training seem unpredictable. CONCLUSION There are statistically significant differences in both the obligatory responses in ERP and the MMNs between the NH and HI groups before the computer-assisted training. Though, these differences disappear after the intervention. This suggests possible training effects regarding the central auditory processing among the HI children.
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Affiliation(s)
- Elisabet Engström
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77 Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86 Stockholm, Sweden.
| | - Petter Kallioinen
- Department of Linguistics, Stockholm University, 106 91 Stockholm, Sweden.
| | - Cecilia Nakeva von Mentzer
- Department of Behavorial Sciences and Learning, Swedish Institute for Disability Research, Linköping University, 581 83 Linköping, Sweden.
| | - Magnus Lindgren
- Department of Psychology, Lund University, 221 00 Lund, Sweden; Cognition, Communication & Learning, Lund University, 221 00 Lund, Sweden.
| | - Marianne Ors
- Department of Clinical Neurophysiology, Skåne University Hospital, 221 85 Lund, Sweden; Cognition, Communication & Learning, Lund University, 221 00 Lund, Sweden.
| | - Birgitta Sahlén
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Logopedics, Phoniatrics & Audiology, Lasarettsgatan 21, 22 185 Lund, Sweden; Cognition, Communication & Learning, Lund University, 221 00 Lund, Sweden.
| | - Björn Lyxell
- Department of Behavorial Sciences and Learning, Swedish Institute for Disability Research, Linköping University, 581 83 Linköping, Sweden.
| | - Inger Uhlén
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, 171 77 Stockholm, Sweden; Department of Otoneurology, Karolinska University Hospital, 141 86 Stockholm, Sweden.
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Abstract
Cochlear implants restore hearing in deaf individuals, but speech perception remains challenging. Poor discrimination of spectral components is thought to account for limitations of speech recognition in cochlear implant users. We investigated how combined variations of spectral components along two orthogonal dimensions can maximize neural discrimination between two vowels, as measured by mismatch negativity. Adult cochlear implant users and matched normal-hearing listeners underwent electroencephalographic event-related potentials recordings in an optimum-1 oddball paradigm. A standard /a/ vowel was delivered in an acoustic free field along with stimuli having a deviant fundamental frequency (+3 and +6 semitones), a deviant first formant making it a /i/ vowel or combined deviant fundamental frequency and first formant (+3 and +6 semitones /i/ vowels). Speech recognition was assessed with a word repetition task. An analysis of variance between both amplitude and latency of mismatch negativity elicited by each deviant vowel was performed. The strength of correlations between these parameters of mismatch negativity and speech recognition as well as participants' age was assessed. Amplitude of mismatch negativity was weaker in cochlear implant users but was maximized by variations of vowels' first formant. Latency of mismatch negativity was later in cochlear implant users and was particularly extended by variations of the fundamental frequency. Speech recognition correlated with parameters of mismatch negativity elicited by the specific variation of the first formant. This nonlinear effect of acoustic parameters on neural discrimination of vowels has implications for implant processor programming and aural rehabilitation.
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Affiliation(s)
- François Prévost
- 1 Department of Speech Pathology and Audiology, McGill University Health Centre, Montreal, Quebec, Canada.,2 International Laboratory for Brain, Music & Sound Research, Montreal, Quebec, Canada
| | - Alexandre Lehmann
- 2 International Laboratory for Brain, Music & Sound Research, Montreal, Quebec, Canada.,3 Department of Otolaryngology-Head and Neck Surgery, McGill University, Montreal, Quebec, Canada.,4 Centre for Research on Brain, Language & Music, Montreal, Quebec, Canada
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