N400 responses of children with primary language disorder: intervention effects

Semantic overreliance as a suboptimal compensation for syntactic impairments in children with Developmental Language Disorder

The neurocognitive dynamics of semantic-syntactic interplay are not well understood in children with and without Developmental Language Disorder (DLD). This study examined the N400, P600 and their interplay in Cantonese-speaking children with DLD and age-matched typically developing (TD) children, by manipulating semantic and syntactic violations in Chinese classifier-noun agreement. Behaviorally, children with DLD demonstrated overall lower accuracy in grammaticality judgment. The N400 and P600 analyses respectively confirmed robust semantic processing but attenuated syntactic processing in the DLD group. Crucially, the N400-P600 interplay analyses revealed that TD children prioritized syntactic processing over semantic processing for outright syntactic violations, as indicated by less N400-P600 dependence and robust P600 dominance, whereas children with DLD relied on semantic processing and showed reduced P600 dominance. These results underscore a challenge to prioritize syntactic processing and (suboptimal) compensatory reliance on semantic processing in children with DLD, compatible with the predictions of the Procedural circuit Deficit Hypothesis.

Similarities in semantic processing across verbal and pictorial domains in school children with developmental language disorder

This study investigates whether Developmental Language Disorder (DLD) is a specific language impairment or a domain-general disorder, thereby addressing the broader question of whether language processing is distinct from or comparable to cognitive processing in other domains. Specifically, we investigate semantic processing in verbal and pictorial domains among 9-12-year-old children with DLD in comparison to an age-matched control group. We measured the amplitude of the event-related potential (ERP) effect indicating semantic processing, the N400, to narratives in the form of both auditorily presented sentences and of wordless picture sequences (comic strips). We compared the N400 effect of predictability in both domains across group. Our findings from a total of 39 participants show an expected N400 effect in both domains in age-matched controls, though with longer latency for the more unfamiliar picture domain but no N400 effect in either domain in children with DLD. This study, thus, indicates similarities in semantic processing across the verbal and the pictorial domains in children with DLD, which is consistent with domain general theories of language.

Intervention factors associated with efficacy, when targeting oral language comprehension of children with or at risk for (Developmental) Language Disorder: A meta-analysis

BACKGROUND

Language interventions are complex behavioural interventions, making it difficult to distinguish the specific factors contributing to efficacy. The efficacy of oral language comprehension interventions varies greatly, but the reasons for this have received little attention.

AIMS

The aim of this meta-analysis was to examine which intervention factors are associated with efficacy (as expressed with effect sizes) regarding interventions aiming to improve oral language comprehension on its own, or together with expressive language, in children under the age of 18 with or at risk for (developmental) language disorder-(D)LD. Whether the interventions for younger and older children differ from one another regarding efficacy or factors possibly associated with efficacy were also examined.

METHODS & PROCEDURES

Studies (n = 46) were identified through two systematic scoping reviews. Factors associated with efficacy were categorized according to the internal characteristics of the intervention as well as factors external to the intervention. Statistical analyses were conducted to examine the association between these factors and intervention efficacy as represented by effect sizes on oral language comprehension outcome measures.

OUTCOMES & RESULTS

Targeting language, language environment or compensatory strategies indicated efficacy, whereas aiming to improve language processing indicated no clinically significant efficacy. Targeting only receptive language was associated with larger effect sizes than targeting both receptive and expressive language. The interventions for younger (2-7 years) and older (8-13 years) children indicated a similar degree of efficacy, but the way in which these results were achieved varied, as comprehension interventions for younger and older children differed from one another. Many factors associated with effect sizes were also associated with each other making interpretation of the results complex.

CONCLUSIONS & IMPLICATIONS

These indicative results suggest that it is not reasonable to target language processing, such as auditory processing or automatization, when aiming to improve oral language comprehension. Targeting receptive language only rather than both receptive and expressive language seems preferable to maximize efficacy when aiming to support solely oral language comprehension instead of targeting both expression and comprehension. The qualitative active ingredients of treatment appear to be more important than the number of intervention hours. Although children of different ages can benefit from interventions to enhance oral language comprehension, the child's age needs to be carefully considered to develop interventions that are optimal. Further research with larger data sets regarding factors contributing to efficacy is still needed before applying these results confidently to clinical practice.

WHAT THIS PAPER ADDS

What is already known on this subject Little is known about the specific intervention factors associated with efficacy of comprehension interventions, and whether these differ between children of different ages. To be able to choose and create optimal comprehension interventions, a better understanding of the mechanisms of change is needed. What this paper adds to the existing knowledge The results indicate that oral comprehension skills of children aged 2-13 years with or at risk for (D)LD can be supported. Targeting language processing, such as auditory processing or automatization, does not seem reasonable when aiming to support oral comprehension. Rather, the interventions should target children's language skills related to comprehension, their language environment or provide children with compensatory strategies. The types of interventions used with younger and older children differed, such that those used with older children were more targeted, adult-directed, applied in formal activities, as well as used taught strategies and more explicit methods of instruction. What are the potential or actual clinical implications of this work? When developing interventions for oral language comprehension, the child's age needs to be considered. Further, what is targeted in an intervention in relation to the aim of the intervention needs careful consideration. The content of the intervention (therapeutic dose form) appears to have precedence over the amount of intervention.

Oral language comprehension interventions in 1-8-year-old children with language disorders or difficulties: A systematic scoping review

Background and aims

The most severe problems in language manifest as difficulties in comprehending oral language. These difficulties are persistent and expose individuals to several risk factors. There is a lack of intervention research in the area of oral language comprehension, and no reviews have focused solely on oral language comprehension interventions in young children. The aim of this review was to identify interventions targeting oral language comprehension in children 8 years or younger with language disorders or difficulties. The review also examined the possible intervention foci, efficacy, and level of evidence of these interventions.

Methods

A systematic scoping review of eight databases was carried out. Twenty of 2399 articles met the inclusion criteria and a further six articles were identified through reference lists of sourced articles. These 26 articles described 25 studies. Altogether 2460 children aged 1-8 years participated in the 25 studies. The data from these studies were extracted and analysed, and the intervention foci, efficacy, and level of evidence were evaluated.Main contribution: The reviewed interventions focused on three aspects: modifying the communicative environment of the child; targeting aspects of the child's language; or targeting the child's language processing. Of the included studies, 80% indicated positive effects on participants' oral language comprehension. The level of evidence of the included studies varied. With few exceptions, researchers and practitioners can have moderate confidence in the results of the included studies indicating that it is possible to ameliorate difficulties in oral language comprehension.

Conclusions

This review summarises the existing evidence on oral language comprehension interventions in young children with language disorders or difficulties. The evidence base is still limited, and more research is urgently needed. The results suggest that though not all interventions seem to provide desired outcomes, there are several interventions indicating efficacy to target problems in oral language comprehension in 1-8-year-old children with language disorders or difficulties. A careful choice of therapy technique and collaboration with people in the child's environment is required to maximize outcomes.Implications: The results suggest that young children's oral language comprehension skills can be improved by guiding parents and clinicians in their communication strategies, and by clinician-implemented interventions targeting aspects of the child's language. The research on interventions targeting children's language processing is limited, and the results mixed. The present study provides information on different oral language comprehension interventions and their outcomes. The findings are readily applicable for clinical use.

A Developmental Perspective on Processing Semantic Context: Preliminary Evidence from Sentential Auditory Word Repetition in School-Aged Children

The current investigation examined the developmental changes involved in processing semantic context in auditorily presented sentences, as well as underlying attentional and suppression mechanisms. Thirty-nine typically developing school-aged children aged 6;0-14;0 years participated in the current cross-sectional sentential auditory word repetition study. Component processes involved in auditory word recognition were examined and their respective developmental trajectories systematically delineated. Experimental manipulations included semantic congruity (congruous, incongruous), sentence constraint (high, low), cloze probability (high, low), and processing mode. High sentence constraints elicited top-down pre-potency type effects, which resulted in active suppression of anticipated cloze words and longer naming latencies of perceived cloze words when violated with conflicting bottom-up information. In addition, developmental changes in component processes reflected underlying changes in attention, with evidence that suppression mechanisms remained relatively constant with age. Findings are interpreted in line with the Trace (McClelland and Elman in Cogn Psychol 18(1):1-86, 1986) model of auditory word recognition.

Semantic Processing of Sentences in Preschoolers With Specific Language Impairment: Evidence From the N400 Effect

PURPOSE

Given the complexity of sentence processing and the specific problems that children with specific language impairment (SLI) experience, we investigated the time course and characteristics of semantic processing at the sentence level in Dutch preschoolers with SLI.

METHOD

We measured N400 responses to semantically congruent and incongruent spoken sentences (e.g., "My father is eating an apple/*blanket") in a group of 37 Dutch preschoolers with SLI and in a group of 25 typically developing (TD) peers. We compared the time course and amplitude of the N400 effect between the two groups.

RESULTS

The TD group showed a strong posterior N400 effect in time windows 300-500 ms and 500-800 ms. In contrast, the SLI group demonstrated only a reliable N400 effect in the later time window, 500-800 ms, and did not show a stronger presence at posterior electrodes.

CONCLUSION

The findings suggest that the neuronal processing of semantic information at sentence level is atypical in preschoolers with SLI compared with TD children.

Research Review: Emanuel Miller Memorial Lecture 2012 - neuroscientific studies of intervention for language impairment in children: interpretive and methodological problems

BACKGROUND

Our ability to look at structure and function of a living brain has increased exponentially since the early 1970s. Many studies of developmental disorders now routinely include a brain imaging or electrophysiological component. Amid current enthusiasm for applications of neuroscience to educational interventions, we need to pause to consider what neuroimaging data can tell us. Images of brain activity are seductive, and have been used to give credibility to commercial interventions, yet we have only a limited idea of what the brain bases of language disorders are, let alone how to alter them.

SCOPE AND FINDINGS

A review of six studies of neuroimaging correlates of language intervention found recurring methodological problems: lack of an adequate control group, inadequate power, incomplete reporting of data, no correction for multiple comparisons, data dredging and failure to analyse treatment effects appropriately. In addition, there is a tendency to regard neuroimaging data as more meaningful than behavioural data, even though it is behaviour that interventions aim to alter.

CONCLUSION

In our current state of knowledge, it would be better to spend research funds doing well-designed trials of behavioural treatment to establish which methods are effective, rather than rushing headlong into functional imaging studies of unproven treatments.

Mismatch negativity responses in children with a diagnosis of childhood apraxia of speech (CAS)

PURPOSE

To evaluate whether a hypothesis suggesting that apraxia of speech results from phonological overspecification could be relevant for childhood apraxia of speech (CAS).

METHOD

High-density EEG was recorded from 5 children with CAS and 5 matched controls, ages 5-8 years, with and without CAS, as they listened to randomized sequences of CV syllables in two oddball paradigms: phonemic (/ba/, /pa/) and allophonic (/pa/, /p(h)a/).

RESULTS

In the phonemic contrast condition, mismatch negativity (MMN) responses to oddball sounds were observed for the typically developing (comparison) group but not the CAS group, although a component similar to an immature mismatch response was apparent. The allophonic contrast did not elicit MMN responses in the comparison group, but in the CAS group, an MMN-like response was observed.

CONCLUSION

The authors propose that these preliminary findings are consistent with a view of CAS as a disorder that not only affects motor planning but also has a phonological component.

Reduced N400 semantic priming effects in adult survivors of paediatric and adolescent traumatic brain injury

The immediate and long-term neural correlates of linguistic processing deficits reported following paediatric and adolescent traumatic brain injury (TBI) are poorly understood. Therefore, the current research investigated event-related potentials (ERPs) elicited during a semantic picture-word priming experiment in two groups of highly functioning individuals matched for various demographic variables and behavioural language performance. Participants in the TBI group had a recorded history of paediatric or adolescent TBI involving injury mechanisms associated with diffuse white matter pathology, while participants in the control group never sustained any insult to the brain. A comparison of N400 Mean Amplitudes elicited during three experimental conditions with varying semantic relatedness between the prime and target stimuli (congruent, semantically related, unrelated) revealed a significantly smaller N400 response in the unrelated condition in the TBI group, indicating residual linguistic processing deviations when processing demands required the quick detection of a between-category (unrelated) violation of semantic expectancy.

A preliminary evaluation of Fast ForWord-Language as an adjuvant treatment in language intervention

PURPOSE

Fast ForWord-Language (FFW-L) is designed to enhance children's processing of auditory-verbal signals and, thus, their ability to learn language. As a preliminary evaluation of this claim, we examined the effects of a 5-week course of FFW-L as an adjuvant treatment with a subsequent 5-week conventional narrative-based language intervention (NBLI) that targeted narrative comprehension and production and grammatical output.

METHOD

Twenty-three children 6-8 years of age with language impairments were assigned randomly to 1 of 3 intervention sequences: (a) FFW-L/NBLI, (b) NBLI/FFW-L, or (c) wait/NBLI. We predicted that after both treatment periods, the FFW-L/NBLI group would show greater gains on measures of narrative ability, conversational grammar, and nonword repetition than the other groups.

RESULTS

After the first 5-week study period, the intervention groups, taken together (i.e., FFW-L/NBLI and NBLI/FFW-L), significantly outperformed the no-treatment wait/NBLI group on 2 narrative measures. At the final test period, all 3 groups displayed significant time-related effects on measures of narrative ability, but there were no statistically significant between-groups effects of intervention sequence.

CONCLUSIONS

This preliminary study provides no evidence to support the claim that FFW-L enhances children's response to a conventional language intervention.