Using a multi-feature paradigm to measure mismatch responses to minimal sound contrasts in children with cochlear implants and hearing aids.

Our aim was to explore whether a multi-feature paradigm (Optimum-1) for eliciting mismatch negativity (MMN) would objectively capture difficulties in perceiving small sound contrasts in children with hearing impairment (HI) listening through their hearing aids (HAs) and/or cochlear implants (CIs). Children aged 5-7 years with HAs, CIs and children with normal hearing (NH) were tested in a free-field setting using a multi-feature paradigm with deviations in pitch, intensity, gap, duration, and location. There were significant mismatch responses across all subjects that were positive (p-MMR) for the gap and pitch deviants (F(1,43) = 5.17, p = 0.028 and F(1,43) = 6.56, p = 0.014, respectively) and negative (MMN) for the duration deviant (F(1,43) = 4.74, p = 0.035). Only the intensity deviant showed a significant group interaction with MMN in the HA group and p-MMR in the CI group (F(2,43) = 3.40, p = 0.043). The p-MMR correlated negatively with age, with the strongest correlation in the NH subjects. In the CI group, the late discriminative negativity (LDN) was replaced by a late positivity with a significant group interaction for the location deviant. Children with severe HI can be assessed through their hearing device with a fast multi-feature paradigm. For further studies a multi-feature paradigm including more complex speech sounds may better capture variation in auditory processing in these children.

Segmental and suprasegmental properties in nonword repetition--an explorative study of the associations with nonword decoding in children with normal hearing and children with bilateral cochlear implants.

This study explored nonword repetition (NWR) and nonword decoding in normal-hearing (NH) children and in children with bilateral cochlear implants (CI). Participants were 11 children, with CI, 5:0-7:11 years (M = 6.5 years), and 11 NH children, individually age-matched to the children with CI. This study fills an important gap in research, since it thoroughly describes detailed aspects of NWR and nonword decoding and their possible associations. All children were assessed after having practiced with a computer-assisted reading intervention with a phonics approach during four weeks. Results showed that NH children outperformed children with CI on the majority of aspects of NWR. The analysis of syllable number in NWR revealed that children with CI made more syllable omissions than did the NH children, and predominantly in prestressed positions. In addition, the consonant cluster analysis in NWR showed significantly more consonant omissions and substitutions in children with CI suggesting that reaching fine-grained levels of phonological processing was particularly difficult for these children. No significant difference was found for nonword-decoding accuracy between the groups, as measured by whole words correct and phonemes correct, but differences were observed regarding error patterns. In children with CI phoneme, deletions occurred significantly more often than in children with NH. The correlation analysis revealed that the ability to repeat consonant clusters in NWR had the strongest associations to nonword decoding in both groups. The absence of as frequent significant associations between NWR and nonword decoding in children with CI compared to children with NH suggest that these children partly use other decoding strategies to compensate for less precise phonological knowledge, for example, lexicalizations in nonword decoding, specifically, making a real word of a nonword.

Computer-assisted reading intervention with a phonics approach for children using cochlear implants or hearing aids.

The present study examined computer-assisted reading intervention with a phonics approach for deaf and hard of hearing (DHH) children in Sweden using cochlear implants or hearing aids, or a combination of both. The study included 48 children, 5, 6 and 7 years of age. Sixteen children with normal hearing (NH) served as a reference group. The first purpose of the study was to compare NH and DHH children's reading ability at pre and post-intervention. The second purpose was to investigate effects of the intervention. Cognitive and demographic factors were analyzed in relation to reading improvement. Results showed no statistically significant difference for reading ability at the group level, although NH children showed overall higher reading scores at both test points. Age comparisons revealed a statistically significant higher reading ability in the NH 7-year-olds compared to the DHH 7-year-olds. The intervention proved successful for word decoding accuracy, passage comprehension and as a reduction of nonword decoding errors in both NH and DHH children. Reading improvement was associated with complex working memory and phonological processing skills in NH children. Correspondent associations were observed with visual working memory and letter knowledge in the DHH children. Age was the only demographic factor that was significantly correlated with reading improvement. The results suggest that DHH children's beginning reading may be influenced by visual strategies that might explain the reading delay in the older children.

Auditory event-related potentials and mismatch negativity in children with hearing loss using hearing aids or cochlear implants - A three-year follow-up study.

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.

Computer-assisted reading intervention for children with sensorineural hearing loss using hearing aids: Effects on auditory event-related potentials and mismatch negativity.

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.

Semantic Processing in Deaf and Hard-of-Hearing Children: Large N400 Mismatch Effects in Brain Responses, Despite Poor Semantic Ability.

Difficulties in auditory and phonological processing affect semantic processing in speech comprehension for deaf and hard-of-hearing (DHH) children. However, little is known about brain responses related to semantic processing in this group. We investigated event-related potentials (ERPs) in DHH children with cochlear implants (CIs) and/or hearing aids (HAs), and in normally hearing controls (NH). We used a semantic priming task with spoken word primes followed by picture targets. In both DHH children and controls, cortical response differences between matching and mismatching targets revealed a typical N400 effect associated with semantic processing. Children with CI had the largest mismatch response despite poor semantic abilities overall; Children with CI also had the largest ERP differentiation between mismatch types, with small effects in within-category mismatch trials (target from same category as prime) and large effects in between-category mismatch trials (where target is from a different category than prime), compared to matching trials. Children with NH and HA had similar responses to both mismatch types. While the large and differentiated ERP responses in the CI group were unexpected and should be interpreted with caution, the results could reflect less precision in semantic processing among children with CI, or a stronger reliance on predictive processing.

SPECT findings in children with specific language impairment.

Findings from 99mTc-HMPAO SPECT measurements at rest in a group of 19 school-age children with specific language impairment (SLI) were compared to a group of 12 children with attention-deficit hyperactivity disorder (ADHD). The regional cerebral blood flow (CBF) distributions were different in the two groups. Children with SLI showed significantly lower CBF values in the right parietal region and in the subcortical region compared to the ADHD group. In addition, the SLI group had symmetric CBF distributions in the left and right temporal regions, whereas the ADHD group showed the usual asymmetry with left-sided hemispheric predominance in the temporal regions. The findings give further evidence for anomalous neurodevelopment with deviant hemispheric lateralization as an important factor in the aetiology of SLI. They also point to the role of subcortical structures in language impairment in childhood. Earlier focus on cortical structures in SLI research needs to be widened to include subcortical regions as well.

Auditory event-related brain potentials in parents of children with specific language impairment.

Auditory event-related brain potentials evoked in response to tone stimuli and to speech stimuli were recorded in a group of parents of children with specific language-impairment and a group of parents of normally speaking children. The parents of the language-impaired children showed longer P3 latencies than the parental control group in the speech task requiring a phonological discrimination, but did not differ from the controls in the linguistically non-demanding tone discrimination task. The longer P3 latency was associated with a positive parental history of language delay. There were no group differences concerning the N1 component in any of the tasks. The findings indicate that parents of children with specific language impairment show signs of deficient late-stage perceptual higher order linguistic processing, whereas the earlier central sensory detection stage of the phonological information is no different from the controls. Our observations are particularly interesting with regard to a study of the children of these two parental groups, where the language-impaired children showed longer P3 latencies than controls in both a tone task and a speech task, whereas there were no differences between the children concerning the N1 component. We propose that deficient late-stage auditory higher order perceptual processing as indexed by the longer P3 latency to speech stimuli observed both in children with specific language-impairment and in their parents may represent a constitutional trait, contributing to the language acquisition difficulties in these children.

Auditory event-related brain potentials in children with specific language impairment.

Event-related brain potentials evoked by tone and speech stimuli were recorded in ten children with specific language impairment and a control group. The patient group showed prolonged P3 latencies in both tasks compared with the controls and smaller P3 amplitude in the speech task. There were no group differences concerning the N1-P2 components. The findings indicate that the children with language impairment showed signs of deficient late-stage auditory perceptual processing whereas the earlier sensory stages as indexed by the N1 were no different from the controls. The results are further discussed within the framework of context updating in working memory.

Computer-assisted training of phoneme-grapheme correspondence for children who are deaf and hard of hearing: effects on phonological processing skills.

OBJECTIVE: Examine deaf and hard of hearing (DHH) children's phonological processing skills in relation to a reference group of children with normal hearing (NH) at two baselines pre intervention. Study the effects of computer-assisted phoneme-grapheme correspondence training in the children. Specifically analyze possible effects on DHH children's phonological processing skills. METHODS: The study included 48 children who participated in a computer-assisted intervention study, which focuses on phoneme-grapheme correspondence. Children were 5, 6, and 7 years of age. There were 32 DHH children using cochlear implants (CI) or hearing aids (HA), or both in combination, and 16 children with NH. The study had a quasi-experimental design with three test occasions separated in time by four weeks; baseline 1 and 2 pre intervention, and 3 post intervention. Children performed tasks measuring lexical access, phonological processing, and letter knowledge. All children were asked to practice ten minutes per day at home supported by their parents. RESULTS: NH children outperformed DHH children on the majority of tasks. All children improved their accuracy in phoneme-grapheme correspondence and output phonology as a function of the computer-assisted intervention. For the whole group of children, and specifically for children with CI, a lower initial phonological composite score was associated with a larger phonological change between baseline 2 and post intervention. Finally, 18 DHH children, whereof 11 children with CI, showed specific intervention effects on their phonological processing skills, and strong effect sizes for their improved accuracy of phoneme-grapheme correspondence. CONCLUSION: For some DHH children phonological processing skills are boosted relatively more by phoneme-grapheme correspondence training. This reflects the reciprocal relationship between phonological change and exposure to and manipulations of letters.

Interdisciplinary and prospective studies necessary to increase insight into developmental language disorders.

UNLABELLED: The study of developmental language disorders is discussed from an interdisciplinary perspective. It is argued that retrospective studies have provided valuable information on developmental language disorders that needs to be integrated into a theoretical model capable of capturing the basic mechanisms of language development. CONCLUSION: It is concluded that interdisciplinary and prospective studies and theoretical work are necessary to increase insight into developmental language disorders.