Using the language characteristics of clinical populations to understand normal language development

Developmental process of the arcuate fasciculus from infancy to adolescence: a diffusion tensor imaging study

We investigated the radiologic developmental process of the arcuate fasciculus (AF) using subcomponent diffusion tensor imaging (DTI) analysis in typically developing volunteers. DTI data were acquired from 96 consecutive typically developing children, aged 0-14 years. AF subcomponents, including the posterior, anterior, and direct AF tracts were analyzed. Success rates of analysis (AR) and fractional anisotropy (FA) values of each subcomponent tract were measured and compared. AR of all subcomponent tracts, except the posterior, showed a significant increase with aging (P < 0.05). Subcomponent tracts had a specific developmental sequence: First, the posterior AF tract, second, the anterior AF tract, and last, the direct AF tract in identical hemispheres. FA values of all subcomponent tracts, except right direct AF tract, showed correlation with subject's age (P < 0.05). Increased AR and FA values were observed in female subjects in young age (0-2 years) group compared with males (P < 0.05). The direct AF tract showed leftward hemispheric asymmetry and this tendency showed greater consolidation in older age (3-14 years) groups (P < 0.05). These findings demonstrated the radiologic developmental patterns of the AF from infancy to adolescence using subcomponent DTI analysis. The AF showed a specific developmental sequence, sex difference in younger age, and hemispheric asymmetry in older age.

Concept formation skills in long-term cochlear implant users

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

Referred speech-language and hearing complaints in the western region of São Paulo, Brazil

OBJECTIVE

The aim of this study was to characterize the epidemiological profile of the population attending primary health care units in the western region of the city of São Paulo, Brazil, highlighting referred speech-language and hearing complaints.

METHOD

This investigation was a cross-sectional observational study conducted in primary health care units. Household surveys were conducted and information was obtained from approximately 2602 individuals, including (but not limited to) data related to education, family income, health issues, access to public services and access to health services. The speech-language and hearing complaints were identified from specific questions.

RESULTS

Our results revealed that the populations participating in the survey were heterogeneous in terms of their demographic and economic characteristics. The prevalence of referred speech-language and hearing complaints in this population was 10%, and only half the users of the public health system in the studied region who had complaints were monitored or received specific treatment.

CONCLUSIONS

The results demonstrate the importance of using population surveys to identify speech-language and hearing complaints at the level of primary health care. Moreover, these findings highlight the need to reorganize the speech-language pathology and audiology service in the western region of São Paulo, as well as the need to improve the Family Health Strategy in areas that do not have a complete coverage, in order to expand and improve the territorial diagnostics and the speech-language pathology and audiology actions related to the prevention, identification, and rehabilitation of human communication disorders.

Spatiotemporal and frequency signatures of word recognition in the developing brain: a magnetoencephalographic study

High-frequency oscillations in the brain open a new window for studies of language development in humans. The objective of this study is to determine the spatiotemporal and frequency signatures of word processing in healthy children. Sixty healthy children aged 6-17 years were studied with a whole-cortex magnetoencephalography (MEG) system using a word recognition paradigm optimized for children. The temporal signature of neuromagnetic activation was measured using averaged waveforms. The spatial and frequency signatures of neuromagnetic activation were assessed with wavelet-based beamformer analyses. The results of waveform analyses showed that the latencies of the first and third neuromagnetic responses changed with age (p<0.01). The source imaging data revealed a clear lateralization of source activation in the 70-120 Hz range in children within the age range of 6 to 13 years of age (p<0.01). Males and females demonstrated different developmental trajectories over the age range of 9 to 13 years of age (p<0.01). These findings suggest that left-hemisphere language processing emerges from early bilateral brain areas with gender optimal neural networks. The neuromagnetic signatures of language development in healthy children may be used as references for future identification of aberrant language function in children with various disorders.

Auditory Skills Development among Children with Developmental Delays and Cochlear Implants

Objectives:

We sought to understand auditory skills outcomes in young children with cochlear implants and developmental delay.

Methods:

Children who received cochlear implants at less than 36 months of age were identified via chart review. Their postimplant auditory skills outcomes were measured with the Auditory Skills Checklist.

Results:

Of 35 children who received cochlear implants before the age of 36 months, 14 children (40%) had additional disabilities or some form of developmental delay. The 12-month postimplant data indicated progress in all groups of children. Children with additional disabilities had the same rate of auditory skills progress as children with no additional disabilities (β = 9.3 versus 9.3; p = 0.5). However, the children with additional disabilities tended to start at a lower baseline skills set (approximately 6 points lower) on the Auditory Skills Checklist. For children with average developmental quotients (at least 80), the rate of progress was twice that of children with a developmental quotient of less than 80, irrespective of a developmental disability (β = 9.9 versus 4.8; p = 0.03). Children with a developmental quotient of less than 80 were less likely to gain skills in discrimination and identification after the first postimplant year.

Conclusions:

Children with additional disabilities make progress in auditory skills, but may not develop higher auditory skills of identification and comprehension within the first 6 months after implantation. Categorizing children according to a cognitive developmental quotient may provide more predictive ability than does categorizing them by disability type.

Television viewing associates with delayed language development

AIM

To identify impact of television viewing on language development.

METHODS

The case-control study included 56 new patients with language delay and 110 normal children, aged 15-48 months. Language delay was diagnosed by reviewing language milestones and Denver-II. Television viewing variables and child/parental characteristics between both groups were interviewed. The data were analyzed by ANOVA and chi-square test. Adjusted odds ratios and 95% confidence intervals were calculated from multivariate logistic regression model.

RESULTS

Forty-six boys and 10 girls; mean [+/-SD] age, 2.11+/-0.47 years of the case group and 59 boys and 51 girls; mean [+/-SD] age, 2.23+/-0.80 years of the control group were enrolled. Children who had language delay usually started watching television earlier at age 7.22+/-5.52 months vs. 11.92+/-5.86 months, p-value<0.001 and also spent more time watching television than normal children (3.05+/-1.90 h/day vs. 1.85+/-1.18 h/day; p-value<0.001). Children who started watching television at<12 months of age and watched television>2 h/day were approximately six times more likely to have language delays.

CONCLUSIONS

There is a relationship between early onset and high frequency of TV viewing and language delay.