Enhancing Syntactic Knowledge in School-Age Children With Developmental Language Disorder: The Promise of Syntactic Priming

PURPOSE

We propose that implicit learning, including syntactic priming, has therapeutic promise to enhance the syntactic knowledge of children with developmental language disorder (DLD).

METHOD

We review the chunk-based learning framework of syntactic learning, the developmental evidence in support of it, and the developmental literature on syntactic priming as an instance of chunk-based statistical learning. We use this framework to help understand the nature of the syntactic learning difficulties of children with DLD. We then briefly review the available explicit treatments for syntactic deficits and end by proposing an implicit training activity that integrates syntactic priming with the principles of statistical learning.

RESULTS

Statistically induced chunk-based learning is a powerful driver of syntactic learning, and syntactic priming is a form of this learning. Repeated priming episodes during everyday language interactions lead children to create abstract and global syntactic representations in long-term memory. We offer some thoughts on an implicit language intervention approach with syntactic priming at its center.

CONCLUSIONS

Children's learning of syntactic structures is influenced by repeated syntactic priming experiences. Including a syntactic priming activity in our language intervention toolbox has the promise to enhance children's syntactic knowledge and sentence comprehension and production abilities.

Determining the Diagnostic Accuracy of the Test of Integrated Language and Literacy Skills for College Students

PURPOSE

This study sought to determine whether the Test of Integrated Language and Literacy Skills (TILLS; Nelson et al., 2016) can accurately identify language disorders in college-aged adults.

METHOD

Fifty-nine college students between the ages of 18 and 23 years were administered the test battery validated by Fidler et al. (2011) for the diagnosis of language disorders as well as the Identification Core (ID Core) subtests of the TILLS validated for ages 12-18 years. Sensitivity and specificity information was calculated for the TILLS at various cut-scores to determine the diagnostic accuracy of the ID Core for this population. Discriminant function analysis was also performed to determine if sensitivity and specificity could be improved using empirically derived discriminant scores.

RESULTS

The recommended cut-score of 42 for ages 12-18 years underidentified individuals with language disorders in this sample. An adjusted cut-score of 51 maximized sensitivity and specificity to acceptable levels. Discriminant function analysis also yielded acceptable sensitivity and specificity (> 80%).

CONCLUSION

Using either an adjusted cut-score for the ID Core or weighted discriminant scores, the TILLS can be used to accurately differentiate between college-aged adults with and without language disorders.

Less Versus More: The Effect of Recast Length in Treatment of Grammatical Errors

PURPOSE

Although conversational recast treatment is generally efficacious, there are many ways in which the individual components of the treatment can be delivered. Some of these are known to enhance treatment, others appear to interfere with learning, and still others appear to have no impact at all. This study tests the potential effect of clinicians' recast length on child learning during a recast treatment.

METHOD

Twenty-six preschool children were treated for grammatical errors using Enhanced Conversational Recast Treatment. Half heard recasts of four or fewer words (Short Recast condition), and half heard recasts of five or more words (Extended Recast condition). Outcome measures included generalization of the treated grammatical form, spontaneous use of these forms, change in mean length of utterances in words, and the number of children in each condition who showed a clinically meaningful response.

RESULTS

There was strong evidence of improvements in the use of grammatical forms targeted by the treatment compared with forms that were tracked but not treated. Twenty children (11 in the Short Recast condition and nine in the Extended Recast condition) showed a clinically meaningful response. There was minimal support for the hypothesis that the length of clinician utterance influenced either progress on a grammatical form targeted by the treatment or on the child's mean length of utterance in words.

CONCLUSIONS

The study adds to the evidence for the efficacy of Enhanced Conversational Recast Treatment. However, there is little evidence that clinicians need to regulate the length of the recast they provide to children.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24653613.

The Dimensionality of Language and Literacy in the School-Age Years

PURPOSE

This was an investigation of the dimensionality of oral and written language to test the hypothesis that a two-factor model with sound/word and sentence/discourse language levels would best fit language and literacy data for a population-based sample in the school-age years.

METHOD

A stratified secondary data set of 1,500 participants was drawn randomly from a larger nationally representative U.S. data set (N = 1,853) gathered during standardization of the Test of Integrated Language and Literacy Skills. A sample of 254 students with prior diagnoses of language and literacy disorders (LLD) was drawn from the full data set. Confirmatory factor analysis was used to compare the hypothesized two-factor model with other theoretically possible models.

RESULTS

The hypothesized two-factor language-levels model had an acceptable-to-good fit to the full data set, as did the three-factor model, with verbal memory added. High interfactor correlation between verbal memory and sentence/discourse constructs, as well as a preference for parsimony, led to the acceptance of the two-factor model as best. This language-levels model had a good fit to the data at ages 8-11 years, and an excellent fit at ages 12-18 years, but only a poor fit for ages 6-7 years (yet still better than other two-factor or unitary models). It had a reasonable fit for students with LLD, although the three-factor model fit their data slightly better.

CONCLUSIONS

Oral and written language abilities during the school-age years are best explained by a two-factor model with sound/word and sentence/discourse language levels and memory as a contributing factor. Implications for identifying and treating language and literacy disorders as multidimensional rather than categorical are discussed.

Evaluating the Equivalence of Telepractice and Traditional Administration of the Test of Integrated Language and Literacy Skills

PURPOSE

This study evaluated the equivalence of the Test of Integrated Language and Literacy Skills (TILLS) when administrated via telepractice (Tele-TILLS) and face-to-face methods.

METHOD

Participants were 51 children and adolescents in three age bands, ages 6-7 years (n = 9), 8-11 years (n = 21), and 12-18 years (n = 21). Data were gathered by 25 volunteer examiners who assessed the same participants twice within a 2- to 4-week period, using Tele-TILLS and traditional methods in randomly selected, counterbalanced order.

RESULTS

Evaluation of identification equivalence showed 96% agreement between methods (49 of 51 decisions), with 39 agreements of no disorder, 10 agreements of yes disorder, and two disagreements (yes disorder for Tele-TILLS and no disorder for traditional). Partial correlations, controlled for test order, showed moderate to high agreement between all composite and subtest scores, except Nonword Repetition. Scoring by examiners and the first author showed high interrater agreement. No differences between Nonword Repetition scores were found for students who wore headsets (n = 12), whereas differences were found for those who did not (n = 34).

CONCLUSIONS

This study provided preliminary evidence that Tele-TILLS results can be equivalent to traditional TILLS, supporting its validity for identifying language/literacy disorder and interpreting profiles. The small, highly homogeneous sample with well-educated parents limits generalizability to the broader population. Caution is warranted when testing 6- to 7-year-old students for whom Nonword Repetition is part of the Identification Core score. Suggestions are provided for optimizing technological setup, preparing facilitators, and making minor modifications in subtest administration.

Translating Enhanced Conversational Recast to a Telepractice Setting

PURPOSE

This investigation adapted a well-studied language treatment method, Enhanced Conversational Recast, paired with auditory bombardment to a teletherapy format.

METHOD

The study used a single case series approach (n = 7) to determine the feasibility of teletherapy with children ages 5 and 6 years of age. Treatment targeted grammatical errors in the context of dialogic reading and craft activities. Clinicians administered 24 doses in the form of focused conversational recasting, followed by 12 doses consisting of simple sentences containing the grammatical forms targeted for remediation. Children were treated for up to 26 sessions, with four children treated on consecutive weekdays and three treated twice a week. Treatment progress was operationalized as generalization of target grammatical forms to untreated linguistic contexts, as well as spontaneous use of the treated form. To control for nontreatment effects, generalization of an untreated form was also tracked throughout the treatment period.

RESULTS

Six of the seven children showed clinically meaningful gains in the use of the grammatical forms targeted for treatment within the treatment period. This was true for children enrolled in both treatment schedules. Learning for treated forms was retained after treatment was discontinued. In comparison, no change was seen for untreated forms for six of the seven children.

CONCLUSIONS

The results suggest that this treatment method is feasible in a telepractice format, even with young children. The range of individual results is generally comparable to previous face-to-face versions of this treatment.

Dynamic Norming for Systematic Analysis of Language Transcripts

PURPOSE

This exploratory study sought to establish the psychometric stability of a dynamic norming system using the Systematic Analysis of Language Transcripts (SALT) databases. Dynamic norming is the process by which clinicians select a subset of the normative database sample matched to their individual client's demographic characteristics.

METHOD

The English Conversation and Student-Selected Story (SSS) Narrative databases from SALT were used to conduct the analyses in two phases. Phase 1 was an exploratory examination of the standard error of measure (SEM) of six clinically relevant transcript metrics at predetermined sampling intervals to determine (a) whether the dynamic norming process resulted in samples with adequate stability and (b) the minimum sample size required for stable results. Phase 2 was confirmatory, as random samples were taken from the SALT databases to simulate clinical comparison samples. These samples were examined (a) for stability of SEM estimations and (b) to confirm the sample size findings from Phase 1.

RESULTS

Results of Phase 1 indicated that the SEMs for the six transcript metrics across both databases were low relative to each metric's scale. Samples as small as 40-50 children in the Conversation database and 20-30 children in the SSS Narrative database resulted in stable SEM estimations. Phase 2 confirmed these findings, indicating that age bands as small as ±4 months from a given center-point resulted in stable estimations provided there were approximately 35 children or more in the comparison sample.

CONCLUSION

Psychometrically stable comparison samples can be achieved using SALT's dynamic norming system that are much smaller than the standard sample size recommended in most tests of children's language.

The Role of Spontaneous Repetitions During Treatment of Morphosyntactic Forms for Children With Developmental Language Disorder

Purpose Children with developmental language disorder sometimes spontaneously repeat clinician models of morphemes targeted for treatment. We examine how spontaneous repeating of clinician models in the form of recasts associates with improved child production of those emerging morphemes. Method Forty-seven preschool children with developmental language disorder participated in Enhanced Conversational Recast therapy and were monitored for spontaneous repetitions of morphemes modeled by the clinician through conversational recasting. We calculated proportion of correct and incorrect productions elicited during treatment and for generalization probes as well as treatment effect sizes. We then used odds ratios to determine the probability that a spontaneous repetition may precede treatment gains and calculated correlations of correct repetitions with correct in-treatment productions of targets and treatment effect sizes. Results Spontaneous repetitions were highly likely to happen just prior to meaningful treatment progress. Children with higher frequencies of correct spontaneous repetitions of morpheme targets also showed higher frequencies of correct productions of these forms during the course of treatment. Furthermore, children with an earlier onset of repetitions and higher frequencies of correct repetitions showed overall larger effect sizes at the end of treatment. Conclusions Children's use of correct forms in their repetitions may serve as a self-scaffold for mastering productions of the correct form via structural priming mechanisms. Tracking spontaneously repeated targets may be a useful milestone for identifying response to treatment.

Not All Procedural Learning Tasks Are Difficult for Adults With Developmental Language Disorder

Purpose The experiment reported here compared two hypotheses for the poor statistical and artificial grammar learning often seen in children and adults with developmental language disorder (DLD; also known as specific language impairment). The procedural learning deficit hypothesis states that implicit learning of rule-based input is impaired, whereas the sequential pattern learning deficit hypothesis states that poor performance is only seen when learners must implicitly compute sequential dependencies. The current experiment tested learning of an artificial grammar that could be learned via feature activation, as observed in an associatively organized lexicon, without computing sequential dependencies and should therefore be learnable on the sequential pattern learning deficit hypothesis, but not on the procedural learning deficit hypothesis. Method Adults with DLD and adults with typical language development (TD) listened to consonant-vowel-consonant-vowel familiarization words from one of two artificial phonological grammars: Family Resemblance (two out of three features) and a control (exclusive OR, in which both consonants are voiced OR both consonants are voiceless) grammar in which no learning was predicted for either group. At test, all participants rated 32 test words as to whether or not they conformed to the pattern in the familiarization words. Results Adults with DLD and adults with TD showed equal and robust learning of the Family Resemblance grammar, accepting significantly more conforming than nonconforming test items. Both groups who were familiarized with the Family Resemblance grammar also outperformed those who were familiarized with the OR grammar, which, as predicted, was learned by neither group. Conclusion Although adults and children with DLD often underperform, compared to their peers with TD, on statistical and artificial grammar learning tasks, poor performance appears to be tied to the implicit computation of sequential dependencies, as predicted by the sequential pattern learning deficit hypothesis.

Data-Informed Guideposts for Decision Making in Enhanced Conversational Recast Treatment

Background To maximize treatment efficiency, it would be useful to determine how long to continue a treatment approach before concluding that it is not effective for a particular client, whether and when generalization of treatment is likely to occur, and at what point to end treatment once a child is approaching mastery. Method We analyzed aggregate data from 117 preschoolers with developmental language disorder from a decade of treatment studies on Enhanced Conversational Recast therapy to determine whether the timing of treatment response impacts its overall effectiveness and whether certain levels of accuracy during treatment enable 100% accurate generalization after treatment ends. Results We found that children who take longer than 10 days to answer one item correctly during treatment are unlikely to ever respond to the treatment approach. Generalization accuracy closely followed treatment accuracy, suggesting the two are tightly linked for this treatment method. We did not find evidence that attaining a certain level of accuracy below 100% during treatment enabled children to generalize with 100% accuracy after treatment ended. Conclusions Clinicians using Enhanced Conversational Recast treatment can use these markers to help make evidence-based decisions in their practice regarding how long to continue treatment. Importantly, these data suggest that stopping treatment before a child has attained 100% accuracy (for at least three sessions) does not ensure that a child will ever reach 100% accuracy on their own.

Predictors of Treatment Response for Preschool Children With Developmental Language Disorder

Purpose Enhanced Conversational Recast treatment is an effective intervention for remediating expressive grammatical deficits in preschool-age children with developmental language disorder, but not all children respond equally well. In this study, we sought to identify which child-level variables predict response to treatment of morphological deficits. Method Predictor variables of interest, including pre-intervention test scores and target morpheme production, age, and mother's level of education (proxy for socio-economic status) were included in analyses. The sample included 105 children (M = 5;1 [years;months]) with developmental language disorder who participated in 5 weeks of daily Enhanced Conversational Recast treatment. Classification and regression tree analysis was used to identify covariates that predicted children's generalization of their trained grammatical morpheme, as measured by treatment effect size d. Results Our analysis indicates that the Structured Photographic Expressive Language Test-Preschool 2 (SPELT-P 2) scores and the Peabody Picture Vocabulary Test-Fourth Edition scores significantly predicted the degree of benefit a child derived from Enhanced Conversational Recast treatment. Specifically, a SPELT-P 2 score above 75 (but still in the impaired range, < 87) combined with a high Peabody Picture Vocabulary Test-Fourth Edition score (> 100) yielded the largest treatment effect size, whereas a SPELT-P 2 score below 75 predicted the smallest treatment effect size. Other variables included in the model did not significantly predict treatment outcomes. Conclusions Understanding individual differences in response to treatment will allow service providers to make evidence-based decisions regarding how likely a child is to benefit from Enhanced Conversational Recast treatment and the expected magnitude of the response based on the child's background characteristics.

Diagnosis of Developmental Language Disorder in Research Studies

Purpose The aim of this study was to investigate the extent to which researchers in the field of developmental language disorder are utilizing validated methods to diagnose their research participants. Method We examined 90 research articles published from 2015 to 2019 that included English-speaking participants from the United States who were identified as having a developmental language disorder or specific language impairment. From these articles, we identified the tests and measures used to identify participants and classify them as healthy or impaired. We then consulted the test manuals and the literature to find information on sensitivity and specificity of the test and the evidence-based cut score that maximized identification accuracy. Results Of the 90 articles examined, 38 (42%) were found to reflect validated diagnostic methods, and 51 (58%) did not. Conclusion Our results illustrate that validated methods are used less than half of the time even by those who should have a high level of expertise and despite calls for increasing scientific rigor in research practices.

Maximizing Treatment Efficiency in Developmental Language Disorder: Positive Effects in Half the Time

Purpose When a behavioral treatment is generally efficacious, the central research questions shift to optimized dose delivery. In this study, we determine whether a validated treatment method can be made more effective or efficient by increasing the dose density employed. Method Twenty children were treated with Enhanced Conversational Recast methods to treat morphological errors. Half received 24 doses per session within a half hour (approximately 1 dose/1.25 min), and the other received the same number of doses within 15 min (approximately 1 dose/38 s). Generalization of morpheme use was probed throughout treatment and at a 6-week follow-up. Spontaneous use of treated morphemes was also tracked. Results Although the treatment was effective overall, there were no significant differences between treatment conditions on any of the outcome measures. Follow-up performance correlated significantly with performance at the end of the treatment period. Conclusion Minimal between-groups differences suggest that performance does not suffer when dose rates are compressed into half the time during treatment, making the high-density dose delivery method a more efficient delivery method. This could make time available within a treatment session to address other goals or allow for more classroom instructional time for the child. Supplemental Material https://doi.org/10.23641/asha.8968559.

Individual Versus Small Group Treatment of Morphological Errors for Children With Developmental Language Disorder

Purpose This study examines the effects of enhanced conversational recast for treating morphological errors in preschoolers with developmental language disorder. The study assesses the effectiveness of this treatment in an individual or group ( n = 2) setting and the possible benefits of exposing a child to his or her partner's treatment target in addition to his or her own. Method Twenty children were assigned to either an individual ( n = 10) or group ( n = 10, 2 per group) condition. Each child received treatment for 1 morpheme (the target morpheme) for approximately 5 weeks. Children in the group condition had a different target from their treatment partner. Pretreatment and end treatment probes were used to compare correct usage of the target morpheme and a control morpheme. For children in the group condition, the correct usage of their treatment partner's target morpheme was also examined. Results Significant treatment effects occurred for both treatment conditions only for morphemes treated directly (target morpheme). There was no statistically significant difference between the treatment conditions at the end of treatment or at follow-up. Children receiving group treatment did not demonstrate significant gains in producing their partner's target despite hearing the target modeled during treatment. Conclusions This study provides the evidence base for enhanced conversational recast treatment in a small group setting, a treatment used frequently in school settings. Results indicate the importance of either attention to the recast or expressive practice (or both) to produce gains with this treatment. Supplemental Material https://doi.org/10.23641/asha.7859975.

Data-driven item selection for the Shirts and Shoes Test

PURPOSE

The first stage of test development is the generation of a pool of potential items to be used in the assessment. Ideally, these items are then tested in the field on members of the population for which the assessment is intended. This initial analysis assures that tests build in validity at the level of the individual items.

METHOD

Seventy-four potential test items developed for the Shirts and Shoes Test (Plante & Vance, 2012) were tested on 513 children between the ages of 3 and 6 years. An Item Response Theory (IRT) approach was used to identify potential items in the item pool which are unsuitable due to one or more types of deviation from the IRT model. Furthermore, an IRT approach provides data that permits the ordering of items by difficulty.

RESULTS

A total of 19 items were discarded due to noteworthy deviations in one or more of the measures related to item response characteristics. The remaining 55 items reflected a range of skill difficulty and were deemed suitable for an age range of 3- to 6-years.

CONCLUSIONS

Item Response Theory can be used productively to identify items that fail to add to the reliability and validity of a test during the earliest stages of test development. The number of items culled for this test demonstrates that the content of the items alone does not assure that the items perform in ways that promote accurate skill measurement.

Learning Without Trying: The Clinical Relevance of Statistical Learning

Purpose

Statistical learning research seeks to identify the means by which learners, with little perceived effort, acquire the complexities of language. In the past 50 years, numerous studies have uncovered powerful learning mechanisms that allow for learning within minutes of exposure to novel language input.

Method

We consider the value of information from statistical learning studies that show potential for making treatment of language disorders faster and more effective.

Results

Available studies include experimental research that demonstrates the conditions under which rapid learning is possible, research showing that these findings apply to individuals with disorders, and translational work that has applied learning principles in treatment and educational contexts. In addition, recent research on memory formation has implications for treatment of language deficits.

Conclusion

The statistical learning literature offers principles for learning that can improve clinical outcomes for children with language impairment. There is potential for further applications of this basic research that is yet unexplored.

Effective Use of Auditory Bombardment as a Therapy Adjunct for Children With Developmental Language Disorders

Purpose

Modeling of grammatical forms has been used in conjunction with conversational recast treatment in various forms. This study tests the relative effect of providing bombardment prior to or after recast treatment.

Method

Twenty-eight children with developmental language disorder participated in daily conversational recast treatment for morpheme errors. This treatment was either preceded or followed by a brief period of intensive auditory bombardment. Generalization to untreated lexical contexts was measured throughout the treatment period to assess the degree of learning and how quickly the onset of measurable learning occurred.

Results

There were no significant differences in elicited use of morphemes for the groups of children who received auditory bombardment before or after enhanced conversational recast treatment. However, there was a difference in the number of children who could be considered treatment responders versus nonresponders, favoring those who received auditory bombardment after recast treatment.

Conclusion

A brief period of auditory bombardment is a relatively low cost addition to recast treatment methods, given how little time it takes. There is a small but measurable advantage to following recast treatment with a period of auditory bombardment.

Supplemental Material

https://doi.org/10.23641/asha.5960005.

Exemplar Variability Facilitates Retention of Word Learning by Children With Specific Language Impairment

Purpose

Variability in the input plays an important role in language learning. The current study examined the role of object variability for new word learning by preschoolers with specific language impairment (SLI).

Method

Eighteen 4- and 5-year-old children with SLI were taught 8 new words in 3 short activities over the course of 3 sessions. Half of the children saw 3 identical objects corresponding to each new word during training (No Variability group); the other half of the children saw 3 different objects corresponding to each new word during training (High Variability group). Children completed vocabulary learning tests for objects seen during training and for new within-category objects that were never seen during training as a test of category generalization. Learning was assessed the day after each training activity, and retention was assessed 3 weeks after the last training session.

Results

There were no group differences on trained or generalization items immediately following training sessions. However, children in the High Variability group demonstrated significantly better retention 3 weeks after experimental training.

Conclusion

These findings demonstrate that object variability facilitates retention of new word learning by children with SLI.

Supplemental Material

https://doi.org/10.23641/asha.5583979.

Feasibility of a Recasting and Auditory Bombardment Treatment With Young Cochlear Implant Users

PURPOSE

There is little to guide clinicians in terms of evidence-based interventions for children with cochlear implants who demonstrate morpheme errors. This feasibility study tested the utility of a treatment targeting grammatical morpheme errors.

METHOD

Three children (ages 4-5 years) received Enhanced Conversational Recast treatment, a version of conversational recast treatment that focuses on a single morpheme error at a time, emphasizes attention to clinician input, and uses high linguistic variability with clinician input. A period of recasting was followed by 24 auditory presentations of the target morpheme in short sentences. After an initial baseline period, children were treated in individual sessions over 21-26 days.

RESULTS

All children showed improved use of targeted grammatical morpheme use, both in elicited contexts and in terms of spontaneous use. Spontaneous use was best for the 2 children who were implanted earliest and whose audiograms showed the best hearing postimplant. Performance by a 3rd child diagnosed with auditory neuropathy spectrum disorder was more variable but still showed positive change.

CONCLUSIONS

The results indicate that the treatment can be effective for children with cochlear implants. The pattern of results across children also suggests potential variables that may moderate treatment effects.

Dose Schedule and Enhanced Conversational Recast Treatment for Children With Specific Language Impairment

Purpose

Dosage has been identified as an important element of treatment that may affect treatment efficacy. The purpose of this study was to examine the role of dose schedule for treatment of grammatical morphology deficits in children with specific language impairment (SLI).

Method

Sixteen 4-to-5-year-old children with SLI participated in a 5-week intervention consisting of equivalent daily Enhanced Conversational Recast treatment (Plante et al., 2014) targeting grammatical morphology. Half of the children received treatment in one 30-min session (massed condition). Half received treatment in three 10-min sessions (spaced condition) within one 4-hr period. Progress was assessed 3 times weekly by probing a child's use of his or her treatment morpheme and untreated morpheme (a maturational control) in untreated contexts.

Results

Pre- to posttreatment morpheme usage differed significantly for children regardless of dosage condition, and pre to post usage of an untreated morpheme was unchanged, demonstrating overall treatment efficacy. There were no differences in treatment effects for the massed and spaced conditions.

Conclusions

The study adds to evidence that Enhanced Conversational Recast can produce positive results in a short period of time for children with SLI. Furthermore, clinicians may have some flexibility in terms of the dose schedule they use to deliver this treatment in an evidence-based manner.

Applying an Integrative Framework of Executive Function to Preschoolers With Specific Language Impairment

Purpose

The first goal of this research was to compare verbal and nonverbal executive function abilities between preschoolers with and without specific language impairment (SLI). The second goal was to assess the group differences on 4 executive function components in order to determine if the components may be hierarchically related as suggested within a developmental integrative framework of executive function.

Method

This study included 26 4- and 5-year-olds diagnosed with SLI and 26 typically developing age- and sex-matched peers. Participants were tested on verbal and nonverbal measures of sustained selective attention, working memory, inhibition, and shifting.

Results

The SLI group performed worse compared with typically developing children on both verbal and nonverbal measures of sustained selective attention and working memory, the verbal inhibition task, and the nonverbal shifting task. Comparisons of standardized group differences between executive function measures revealed a linear increase with the following order: working memory, inhibition, shifting, and sustained selective attention.

Conclusion

The pattern of results suggests that preschoolers with SLI have deficits in executive functioning compared with typical peers, and deficits are not limited to verbal tasks. A significant linear relationship between group differences across executive function components supports the possibility of a hierarchical relationship between executive function skills.

Neural Correlates of Morphology Acquisition through a Statistical Learning Paradigm

The neural basis of statistical learning as it occurs over time was explored with stimuli drawn from a natural language (Russian nouns). The input reflected the "rules" for marking categories of gendered nouns, without making participants explicitly aware of the nature of what they were to learn. Participants were scanned while listening to a series of gender-marked nouns during four sequential scans, and were tested for their learning immediately after each scan. Although participants were not told the nature of the learning task, they exhibited learning after their initial exposure to the stimuli. Independent component analysis of the brain data revealed five task-related sub-networks. Unlike prior statistical learning studies of word segmentation, this morphological learning task robustly activated the inferior frontal gyrus during the learning period. This region was represented in multiple independent components, suggesting it functions as a network hub for this type of learning. Moreover, the results suggest that subnetworks activated by statistical learning are driven by the nature of the input, rather than reflecting a general statistical learning system.

An fMRI study of implicit language learning in developmental language impairment

Individuals with developmental language impairment can show deficits into adulthood. This suggests that neural networks related to their language do not normalize with time. We examined the ability of 16 adults with and without impaired language to learn individual words in an unfamiliar language. Adults with impaired language were able to segment individual words from running speech, but needed more time to do so than their normal-language peers. ICA analysis of fMRI data indicated that adults with language impairment activate a neural network that is comparable to that of adults with normal language. However, a regional analysis indicated relative hyperactivation of a collection of regions associated with language processing. These results are discussed with reference to the Statistical Learning Framework and the sub-skills thought to relate to word segmentation.

•

Adults with developmental language impairment were imaged during a word segmentation task in an unfamiliar natural language.

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Impaired adults learned to identify individual words, although it took them longer than their typical language peers.

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The impaired group used the same learning network as the typical group, arguing against recruitment of additional regions.

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Hyper-activation in language regions characterized the impaired group, unless performance was equated between groups.

•

This suggests that hyper-activation for the impaired group reflects greater effort by learners at earlier stages of learning.

Reliability of the Test of Integrated Language and Literacy Skills (TILLS)

BACKGROUND

As new standardized tests become commercially available, it is critical that clinicians have access to the information about a test's psychometric properties, including aspects of reliability.

AIMS

The purpose of the three studies reported in this article was to investigate the reliability of a new test, the Test of Integrated Language and Literacy Skills (TILLS), with consideration of both internal and external sources of measurement error.

METHODS & PROCEDURES

The TILLS was administered to children aged 6;0-18;11 years. The participants varied in terms of their language and literacy skills and included children with typical language development as well as those diagnosed with language or learning disability. The sample of children also varied in terms of their racial and socioeconomic backgrounds. Study 1 (N = 1056) assessed the internal consistency of TILLS calculating the coefficient omega for each subtest. Study 2 (N = 103) and Study 3 (N = 39) used the intra-class correlation coefficients to report on test-retest and inter-rater reliability respectively.

OUTCOMES & RESULTS

The results indicate strong internal consistency and inter-rater reliability for all subtests of TILLS. The test-retest reliability was strong for all but one subtest, for which the intra-class correlation coefficient was in the acceptable range.

CONCLUSION & IMPLICATIONS

This article provides clinicians with essential scientific information that supports the internal and external reliability of a new test of oral and written language skills, the TILLS. Information about reliability is critical for guiding the selection of an appropriate diagnostic tool amongst a number of options.

The nature of the language input affects brain activation during learning from a natural language

Artificial language studies have demonstrated that learners are able to segment individual word-like units from running speech using the transitional probability information. However, this skill has rarely been examined in the context of natural languages, where stimulus parameters can be quite different. In this study, two groups of English-speaking learners were exposed to Norwegian sentences over the course of three fMRI scans. One group was provided with input in which transitional probabilities predicted the presence of target words in the sentences. This group quickly learned to identify the target words and fMRI data revealed an extensive and highly dynamic learning network. These results were markedly different from activation seen for a second group of participants. This group was provided with highly similar input that was modified so that word learning based on syllable co-occurrences was not possible. These participants showed a much more restricted network. The results demonstrate that the nature of the input strongly influenced the nature of the network that learners employ to learn the properties of words in a natural language.

Dynamic Data Visualization with Weave and Brain Choropleths

This article introduces the neuroimaging community to the dynamic visualization workbench, Weave (https://www.oicweave.org/), and a set of enhancements to allow the visualization of brain maps. The enhancements comprise a set of brain choropleths and the ability to display these as stacked slices, accessible with a slider. For the first time, this allows the neuroimaging community to take advantage of the advanced tools already available for exploring geographic data. Our brain choropleths are modeled after widely used geographic maps but this mashup of brain choropleths with extant visualization software fills an important neuroinformatic niche. To date, most neuroinformatic tools have provided online databases and atlases of the brain, but not good ways to display the related data (e.g., behavioral, genetic, medical, etc). The extension of the choropleth to brain maps allows us to leverage general-purpose visualization tools for concurrent exploration of brain images and related data. Related data can be represented as a variety of tables, charts and graphs that are dynamically linked to each other and to the brain choropleths. We demonstrate that the simplified region-based analyses that underlay choropleths can provide insights into neuroimaging data comparable to those achieved by using more conventional methods. In addition, the interactive interface facilitates additional insights by allowing the user to filter, compare, and drill down into the visual representations of the data. This enhanced data visualization capability is useful during the initial phases of data analysis and the resulting visualizations provide a compelling way to publish data as an online supplement to journal articles.

Executive Function in SLI: Recent Advances and Future Directions

This paper provides a review of recent research on executive function abilities in children with specific language impairment (SLI). Across several studies, children with SLI are reported to perform worse than typically developing peers on measures of sustained attention, working memory, inhibition, and attention shifting. However, few studies have considered multiple executive function components simultaneously and even fewer have examined the underlying relationship between executive function deficits and impaired language acquisition. We argue that in order to fully understand the nature of executive function deficits in SLI, the field must move past simply identifying weaknesses to instead test models of executive function development and explore the nature of the relationship between executive function and language. Future research directions are recommended in order to achieve these goals.

Input Variability Facilitates Unguided Subcategory Learning in Adults

PURPOSE

This experiment investigated whether input variability would affect initial learning of noun gender subcategories in an unfamiliar, natural language (Russian), as it is known to assist learning of other grammatical forms.

METHOD

Forty adults (20 men, 20 women) were familiarized with examples of masculine and feminine Russian words. Half of the participants were familiarized with 32 different root words in a high-variability condition. The other half were familiarized with 16 different root words, each repeated twice for a total of 32 presentations in a high-repetition condition. Participants were tested on untrained members of the category to assess generalization. Familiarization and testing was completed 2 additional times.

RESULTS

Only participants in the high-variability group showed evidence of learning after an initial period of familiarization. Participants in the high-repetition group were able to learn after additional input. Both groups benefited when words included 2 cues to gender compared to a single cue.

CONCLUSIONS

The results demonstrate that the degree of input variability can influence learners' ability to generalize a grammatical subcategory (noun gender) from a natural language. In addition, the presence of multiple cues to linguistic subcategory facilitated learning independent of variability condition.

Variability in the language input to children enhances learning in a treatment context

PURPOSE

Artificial language learning studies have demonstrated that learners exposed to many different nonword combinations representing a grammatical form demonstrate rapid learning of that form without explicit instruction. However, learners presented with few exemplars, even when they are repeated frequently, fail to learn the underlying grammar. This study translated this experimental finding in a therapeutic context.

METHOD

Eighteen preschool children with language impairment received conversational recast treatment for morpheme errors. Over a 6-week period, half heard 12 unique verbs twice each during recasts (low-variability condition), and half heard 24 unique verbs (high-variability condition). Children's use of trained and untrained morphemes on generalization probes as well as spontaneous use of trained morphemes was tracked throughout treatment.

RESULTS

The high-variability condition only produced significant change in children's use of trained morphemes, but not untrained morphemes. Data from individual children confirmed that more children in the high- than the low-variability condition showed a strong treatment effect. Children in the high-variability condition also produced significantly more unique utterances containing their trained morpheme than children in the low-variability condition.

CONCLUSION

The results support the use of highly variable input in a therapeutic context to facilitate grammatical morpheme learning.

Language lateralization shifts with learning by adults

For the majority of the population, language is a left-hemisphere lateralized function. During childhood, a pattern of increasing left lateralization for language has been described in brain imaging studies, suggesting that this trait develops. This development could reflect change due to brain maturation or change due to skill acquisition, given that children acquire and refine language skills as they mature. We test the possibility that skill acquisition, independent of age-associated maturation can result in shifts in language lateralization in classic language cortex. We imaged adults exposed to an unfamiliar language during three successive fMRI scans. Participants were then asked to identify specific words embedded in Norwegian sentences. Exposure to these sentences, relative to complex tones, resulted in consistent activation in the left and right superior temporal gyrus. Activation in this region became increasingly left-lateralized with repeated exposure to the unfamiliar language. These results demonstrate that shifts in lateralization can be produced in the short term within a learning context, independent of maturation.

Bidirectional iterative parcellation of diffusion weighted imaging data: separating cortical regions connected by the arcuate fasciculus and extreme capsule

This paper introduces a Bidirectional Iterative Parcellation (BIP) procedure designed to identify the location and size of connected cortical regions (parcellations) at both ends of a white matter tract in diffusion weighted images. The procedure applies the FSL option "probabilistic tracking with classification targets" in a bidirectional and iterative manner. To assess the utility of BIP, we applied the procedure to the problem of parcellating a limited set of well-established gray matter seed regions associated with the dorsal (arcuate fasciculus/superior longitudinal fasciculus) and ventral (extreme capsule fiber system) white matter tracts in the language networks of 97 participants. These left hemisphere seed regions and the two white matter tracts, along with their right hemisphere homologues, provided an excellent test case for BIP because the resulting parcellations overlap and their connectivity via the arcuate fasciculi and extreme capsule fiber systems are well studied. The procedure yielded both confirmatory and novel findings. Specifically, BIP confirmed that each tract connects within the seed regions in unique, but expected ways. Novel findings included increasingly left-lateralized parcellations associated with the arcuate fasciculus/superior longitudinal fasciculus as a function of age and education. These results demonstrate that BIP is an easily implemented technique that successfully confirmed cortical connectivity patterns predicted in the literature, and has the potential to provide new insights regarding the architecture of the brain.

Evidence that neurovascular coupling underlying the BOLD effect increases with age during childhood

Functional MRI using blood-oxygen-level-dependent (BOLD) imaging has provided unprecedented insights into the maturation of the human brain. Task-based fMRI studies have shown BOLD signal increases with age during development (ages 5-18) for many cognitive domains such as language and executive function, while functional connectivity (resting-state) fMRI studies investigating regionally synchronous BOLD fluctuations have revealed a developing functional organization of the brain from a local into a more distributed architecture. However, interpretation of these results is confounded by the fact that the BOLD signal is directly related to blood oxygenation driven by changes in blood flow and only indirectly related to neuronal activity, and may thus be affected by changing neuronal-vascular coupling. BOLD signal and cerebral blood flow (CBF) were measured simultaneously in a cohort of 113 typically developing awake participants ages 3-18 performing a narrative comprehension task. Using a novel voxelwise wild bootstrap analysis technique, an increased ratio of BOLD signal to relative CBF signal change with age (indicative of increased neuronal-vascular coupling) was seen in the middle temporal gyri and the left inferior frontal gyrus. Additionally, evidence of decreased relative oxygen metabolism (indicative of decreased neuronal activity) with age was found in the same regions. These findings raise concern that results of developmental BOLD studies cannot be unambiguously attributed to neuronal activity. Astrocytes and astrocytic processes may significantly affect the maturing functional architecture of the brain, consistent with recent research demonstrating a key role for astrocytes in mediating increased CBF following neuronal activity and for astrocyte processes in modulating synaptic connectivity.

Learning of grammar-like visual sequences by adults with and without language-learning disabilities

PURPOSE

Two studies examined learning of grammar-like visual sequences to determine whether a general deficit in statistical learning characterizes this population. Furthermore, we tested the hypothesis that difficulty in sustaining attention during the learning task might account for differences in statistical learning.

METHOD

In Study 1, adults with normal language (NL) or language-learning disability (LLD) were familiarized with the visual artificial grammar and then tested using items that conformed or deviated from the grammar. In Study 2, a 2nd sample of adults with NL and LLD were presented auditory word pairs with weak semantic associations (e.g., groom + clean) along with the visual learning task. Participants were instructed to attend to visual sequences and to ignore the auditory stimuli. Incidental encoding of these words would indicate reduced attention to the primary task.

RESULTS

In Studies 1 and 2, both groups demonstrated learning and generalization of the artificial grammar. In Study 2, neither the NL nor the LLD group appeared to encode the words presented during the learning phase.

CONCLUSION

The results argue against a general deficit in statistical learning for individuals with LLD and demonstrate that both NL and LLD learners can ignore extraneous auditory stimuli during visual learning.

Dynamic changes in network activations characterize early learning of a natural language

Those who are initially exposed to an unfamiliar language have difficulty separating running speech into individual words, but over time will recognize both words and the grammatical structure of the language. Behavioral studies have used artificial languages to demonstrate that humans are sensitive to distributional information in language input, and can use this information to discover the structure of that language. This is done without direct instruction and learning occurs over the course of minutes rather than days or months. Moreover, learners may attend to different aspects of the language input as their own learning progresses. Here, we examine processing associated with the early stages of exposure to a natural language, using fMRI. Listeners were exposed to an unfamiliar language (Icelandic) while undergoing four consecutive fMRI scans. The Icelandic stimuli were constrained in ways known to produce rapid learning of aspects of language structure. After approximately 4 min of exposure to the Icelandic stimuli, participants began to differentiate between correct and incorrect sentences at above chance levels, with significant improvement between the first and last scan. An independent component analysis of the imaging data revealed four task-related components, two of which were associated with behavioral performance early in the experiment, and two with performance later in the experiment. This outcome suggests dynamic changes occur in the recruitment of neural resources even within the initial period of exposure to an unfamiliar natural language.

Involvement of the right hemisphere in reading comprehension: a DTI study

The Simple View of reading emphasizes the critical role of two factors in normal reading skills: word recognition and reading comprehension. The current study aims to identify the anatomical support for aspects of reading performance that fall within these two components. Fractional anisotropy (FA) values were obtained from diffusion tensor images in twenty-one typical adolescents and young adults using the tract based spatial statistics (TBSS) method. We focused on the arcuate fasciculus (AF) and inferior longitudinal fasciculus (ILF) as fiber tracts that connect regions already implicated in the distributed cortical network for reading. Our results demonstrate dissociation between word-level and narrative-level reading skills: the FA values for both left and right ILF were correlated with measures of word reading, while only the left ILF correlated with reading comprehension scores. FA in the AF, however, correlated only with reading comprehension scores, bilaterally. Correlations with the right AF were particularly robust, emphasizing the contribution of the right hemisphere, especially the frontal lobe, to reading comprehension performance on the particular passage comprehension test used in this study. The anatomical dissociation between these reading skills is supported by the Simple View theory and may shed light on why these two skills dissociate in those with reading disorders.

Unilateral deafness in children affects development of multi-modal modulation and default mode networks

Monaural auditory input due to congenital or acquired unilateral hearing loss (UHL) may have neurobiological effects on the developing brain. Using functional magnetic resonance imaging (fMRI), we investigated the effect of UHL on the development of functional brain networks used for cross-modal processing. Children ages 7-12 with moderate or greater unilateral hearing loss of sensorineural origin (UHL-SN; N = 21) and normal-hearing controls (N = 23) performed an fMRI-compatible adaptation of the Token Test involving listening to a sentence such as "touched the small green circle and the large blue square" and simultaneously viewing an arrow touching colored shapes on a video. Children with right or severe-to-profound UHL-SN displayed smaller activation in a region encompassing the right inferior temporal, middle temporal, and middle occipital gyrus (BA 19/37/39), evidencing differences due to monaural hearing in cross-modal modulation of the visual processing pathway. Children with UHL-SN displayed increased activation in the left posterior superior temporal gyrus, likely the result either of more effortful low-level processing of auditory stimuli or differences in cross-modal modulation of the auditory processing pathway. Additionally, children with UHL-SN displayed reduced deactivation of anterior and posterior regions of the default mode network. Results suggest that monaural hearing affects the development of brain networks related to cross-modal sensory processing and the regulation of the default network during processing of spoken language.

A stereoscopic system for viewing the temporal evolution of brain activity clusters in response to linguistic stimuli

In this paper, we present a novel application, 3D+Time Brain View, for the stereoscopic visualization of functional Magnetic Resonance Imaging (fMRI) data gathered from participants exposed to unfamiliar spoken languages. An analysis technique based on Independent Component Analysis (ICA) is used to identify statistically significant clusters of brain activity and their changes over time during different testing sessions. That is, our system illustrates the temporal evolution of participants' brain activity as they are introduced to a foreign language through displaying these clusters as they change over time. The raw fMRI data is presented as a stereoscopic pair in an immersive environment utilizing passive stereo rendering. The clusters are presented using a ray casting technique for volume rendering. Our system incorporates the temporal information and the results of the ICA into the stereoscopic 3D rendering, making it easier for domain experts to explore and analyze the data.

Data on the safety of repeated MRI in healthy children

Purpose

To address the question of the safety of MRI for research in normal, healthy children. We examined MRI, neurocognitive and biometric data collected in a group of healthy, normally developing children who have participated in a 10 year longitudinal fMRI study.

Materials and methods

Thirty-one healthy children ranging in age from 5 to 7 years were enrolled between 2000 and 2002 and were tested yearly as part of a longitudinal study of normal language development. Twenty-eight of these children have completed multiple neuroimaging, neurocognitive and biometric exams. These children ranged in age from 5 to 18 years during the course of the study and were exposed to up to 10 annual MRI scans. Linear regression of the IQ (WISC-III) (Wechsler, 1991), executive function (BRIEF) (Gioia et al., 2002), and language (OWLS) (Carrow-Woolfolk, 1995) measures was performed against the number of years of exposure to MRI in the study. Body mass index (BMI) (Ogden et al., 2006) was also examined as a function of years and compared with normative values.

Results

The WISC-III Full Scale (FSIQ) in our longitudinal cohort was higher than the average at baseline. There was no significant change over time in mean FSIQ p = 0.80, OWLS p = 0.16, or BRIEF p = 0.67. Similarly, over 10 years there were no significant changes in the Coding subtest of WISC III and height and body mass index did not deviate from norms (50th percentile).

Conclusions

Examination of neurocognitive and biometric data from a decade-long, longitudinal fMRI study of normal language development in this small, longitudinal sample of healthy children in the age range of 5 to 18 years, who received up to 10 MRI scans, provides scientific evidence to support the belief that MRI poses minimal risk for use in research with healthy children.

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We examined the safety of MRI for research in normal, healthy children.

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We looked the change overtime of neurocognitive data in a longitudinal fMRI study.

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There was no significant change over time in measured neurocognitive tests.

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Body mass index of these children did not deviate from norms.

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MRI poses minimal risk for use in research with healthy children.

What influences children's conceptualizations of language input?

PURPOSE

Children learning language conceptualize the nature of input they receive in ways that allow them to understand and construct utterances they have never heard before. This study was designed to illuminate the types of information children with and without specific language impairment (SLI) focus on to develop their conceptualizations and whether they can rapidly shift their initial conceptualizations if provided with additional input.

METHOD

In 2 studies, preschool children with and without SLI were exposed to an artificial language, the characteristics of which allowed for various types of conceptualizations about its fundamental properties. After being familiarized with the language, children were asked to judge test strings that conformed to the input in 1 of 4 different ways.

RESULTS

All children preferred test items that reflected a narrow conceptualization of the input (i.e., items most like those heard during familiarization). Children showed a strong preference for phonology as a defining property of the artificial language. Restructuring the input to the child could induce them to track word order information as well.

CONCLUSION

Children tend toward narrow conceptualizations of language input, but the nature of their conceptualizations can be influenced by the nature of the input they receive.

Talker discrimination in preschool children with and without specific language impairment

Variability inherently present between multiple talkers can prove beneficial in the context of learning. However, the performance during learning paradigms by children with specific language impairment (SLI) remains below typically developing peers, even when multiple talkers are used. Preschool children with typically developing language (n = 17) and SLI (n = 17) participated in a talker discrimination task. Five different pairings of talkers (same male, different males, same female, different females, male + female) were used to present 50 spoken words. Children with SLI were significantly poorer in discriminating same and different male speakers compared to their typical peers. The present findings demonstrate that preschool children with SLI can experience difficulty distinguishing between talkers. Poor sensitivity to variation in talkers may contribute to poor learning in SLI for contexts where multiple talker input should benefit the learner.

LEARNING OUTCOMES

The reader will recognize that the presence of multiple talkers (voices) can assist or detract from performance on cognitive tasks. Children with specific language impairment are less proficient than their peers in distinguishing the same from different talkers.

Exemplar variability facilitates rapid learning of an otherwise unlearnable grammar by individuals with language-based learning disability

PURPOSE

Even without explicit instruction, learners are able to extract information about the form of a language simply by attending to input that reflects the underlying grammar. In this study, the authors explored the role of variability in this learning by asking whether varying the number of unique exemplars heard by the learner affects learning of an artificial syntactic form.

METHOD

Learners with normal language (n = 16) and language-based learning disability (LLD; n = 16) were exposed to strings of nonwords that represented an underlying grammar. Half of the learners heard 3 exemplars 16 times each (low variability group), and the other half of the learners heard 24 exemplars twice each (high variability group). Learners were then tested for recognition of items heard and generalization of the grammar with new nonword strings.

RESULTS

Only those learners with LLD who were in the high variability group were able to demonstrate generalization of the underlying grammar. For learners with normal language, both those in the high and the low variability groups showed generalization of the grammar, but relative effect sizes suggested a larger learning effect in the high variability group.

CONCLUSION

The results demonstrate that the structure of the learning context can determine the ability to generalize from specific training items to novel cases.

Written narrative characteristics in adults with language impairment

PURPOSE

Adults with language-based disabilities are known to have deficits in oral language; however, less is known about their written language skills. Two studies were designed to characterize the writing of adults with language-based disabilities.

METHOD

In Study 1, 60 adults, 30 with language impairment and 30 with typical language, completed written narratives. Forty-one written language measures were analyzed. In Study 2, the measures that had the most potential for reliably indexing deficits were analyzed in an additional 77 adults.

RESULTS

Three measures that showed significant between-group differences and had robust effect sizes in Study 1, total number of verbs, 1-part verbs, and errors, were applied to the samples in Study 2. A group difference for percentage of errors was replicated in the second sample. A discriminant analysis identified 75% of the adults with language impairment and 30% of the adults with typical language as having an impairment based on the percent of written errors.

CONCLUSIONS

The writing task revealed consistent group differences in written errors and is clinically applicable in describing a client's writing. However, the number of written errors was not robust enough to identify whether an adult had a language impairment or not.

Predicting dyslexia at age 11 from a risk index questionnaire at age 5

This study focused on predicting dyslexia in children ahead of formal literacy training. Because dyslexia is a constitutional impairment, risk factors should be seen in preschool. It was hypothesized that data gathered at age 5 using questions targeting the dyslexia endophenotype should be reliable and valid predictors of dyslexia at age 11. A questionnaire was given to caretakers of 120 5-year-old children, and a risk index score was calculated based on questions regarding health, laterality, motor skills, language, special needs education and heredity. An at-risk group (n = 25) and matched controls (n = 24) were followed until age 11, when a similar questionnaire and literacy tests were administered to the children who participated in the follow-up study (22 at risk and 20 control). Half of the at-risk children and two of the control children at age 5 were identified as having dyslexia at age 11 (8 girls and 5 boys). It is concluded that it is possible to identify children at the age of 5 who will have dyslexia at the age of 11 through a questionnaire approach.

Diffusion tensor imaging reveals white matter microstructure correlations with auditory processing ability

OBJECTIVE

Correlation of white matter microstructure with various cognitive processing tasks and with overall intelligence has been previously demonstrated. We investigate the correlation of white matter microstructure with various higher-order auditory processing tasks, including interpretation of speech-in-noise, recognition of low-pass frequency filtered words, and interpretation of time-compressed sentences at two different values of compression. These tests are typically used to diagnose auditory processing disorder (APD) in children. Our hypothesis is that correlations between white matter microstructure in tracts connecting the temporal, frontal, and parietal lobes, as well as callosal pathways, will be seen. Previous functional imaging studies have shown correlations between activation in temporal, frontal, and parietal regions from higher-order auditory processing tasks. In addition, we hypothesize that the regions displaying correlations will vary according to the task because each task uses a different set of skills.

DESIGN

Diffusion tensor imaging (DTI) data were acquired from a cohort of 17 normal-hearing children aged 9 to 11 yrs. Fractional anisotropy (FA), a measure of white matter fiber tract integrity and organization, was computed and correlated on a voxelwise basis with performance on the auditory processing tasks, controlling for age, sex, and full-scale IQ.

RESULTS

Divergent correlations of white matter FA depending on the particular auditory processing task were found. Positive correlations were found between FA and speech-in-noise in white matter adjoining prefrontal areas and between FA and filtered words in the corpus callosum. Regions exhibiting correlations with time-compressed sentences varied depending on the degree of compression: the greater degree of compression (with the greatest difficulty) resulted in correlations in white matter adjoining prefrontal (dorsal and ventral), whereas the smaller degree of compression (with less difficulty) resulted in correlations in white matter adjoining audiovisual association areas and the posterior cingulate. Only the time-compressed sentences with the lowest degree of compression resulted in positive correlations in the centrum semiovale; all the other tasks resulted in negative correlations.

CONCLUSIONS

The dependence of performance on higher-order auditory processing tasks on brain anatomical connectivity was seen in normal-hearing children aged 9 to 11 yrs. Results support a previously hypothesized dual-stream (dorsal and ventral) model of auditory processing, and that higher-order processing tasks rely less on the dorsal stream related to articulatory networks and more on the ventral stream related to semantic comprehension. Results also show that the regions correlating with auditory processing vary according to the specific task, indicating that the neurological bases for the various tests used to diagnose APD in children may be partially independent.

A linear structural equation model for covert verb generation based on independent component analysis of FMRI data from children and adolescents

Human language is a complex and protean cognitive ability. Young children, following well defined developmental patterns learn language rapidly and effortlessly producing full sentences by the age of 3 years. However, the language circuitry continues to undergo significant neuroplastic changes extending well into teenage years. Evidence suggests that the developing brain adheres to two rudimentary principles of functional organization: functional integration and functional specialization. At a neurobiological level, this distinction can be identified with progressive specialization or focalization reflecting consolidation and synaptic reinforcement of a network (Lenneberg, 1967; Muller et al., 1998; Berl et al., 2006). In this paper, we used group independent component analysis and linear structural equation modeling (McIntosh and Gonzalez-Lima, 1994; Karunanayaka et al., 2007) to tease out the developmental trajectories of the language circuitry based on fMRI data from 336 children ages 5–18 years performing a blocked, covert verb generation task. The results are analyzed and presented in the framework of theoretical models for neurocognitive brain development. This study highlights the advantages of combining both modular and connectionist approaches to cognitive functions; from a methodological perspective, it demonstrates the feasibility of combining data-driven and hypothesis driven techniques to investigate the developmental shifts in the semantic network.

Identification of adults with developmental language impairments

PURPOSE

To assess the utility of a wide range of language measures (phonology, morphology, syntax, and semantics) for the identification of adults with developmental language impairment.

METHOD

Measures were administered to 3 groups of adults, each representing a population expected to demonstrate high levels of language impairment, and to matched control groups.

RESULTS

Three measures were the strongest contributors to identification of language impairment in the 3 groups of adults. These measures, combined, maximized identification of members of the clinical groups as having impaired language (sensitivity) and members of the control groups as having typical language (specificity).

CONCLUSION

This suggests that a relatively brief battery could have utility for identifying developmental language impairment during the adult years.

Neural substrates of attentive listening assessed with a novel auditory Stroop task

A common explanation for the interference effect in the classic visual Stroop test is that reading a word (the more automatic semantic response) must be suppressed in favor of naming the text color (the slower sensory response). Neuroimaging studies also consistently report anterior cingulate/medial frontal, lateral prefrontal, and anterior insular structures as key components of a network for Stroop-conflict processing. It remains unclear, however, whether automatic processing of semantic information can explain the interference effect in other variants of the Stroop test. It also is not known if these frontal regions serve a specific role in visual Stroop conflict, or instead play a more universal role as components of a more generalized, supramodal executive-control network for conflict processing. To address these questions, we developed a novel auditory Stroop test in which the relative dominance of semantic and sensory feature processing is reversed. Listeners were asked to focus either on voice gender (a more automatic sensory discrimination task) or on the gender meaning of the word (a less automatic semantic task) while ignoring the conflicting stimulus feature. An auditory Stroop effect was observed when voice features replaced semantic content as the “to-be-ignored” component of the incongruent stimulus. Also, in sharp contrast to previous Stroop studies, neural responses to incongruent stimuli studied with functional magnetic resonance imaging revealed greater recruitment of conflict loci when selective attention was focused on gender meaning (semantic task) over voice gender (sensory task). Furthermore, in contrast to earlier Stroop studies that implicated dorsomedial cortex in visual conflict processing, interference-related activation in both of our auditory tasks was localized ventrally in medial frontal areas, suggesting a dorsal-to-ventral separation of function in medial frontal cortex that is sensitive to stimulus context.