Statistical Learning in Specific Language Impairment: A Meta-Analysis

The Effectiveness of Individualized Morphosyntactic Target Identification and Explicit Intervention Using the SHAPE CODING System for Children With Developmental Language Disorder and the Impact of Within-Session Dosage

PURPOSE

We investigated the effectiveness of a highly individualized morphosyntactic intervention using the SHAPE CODING™ system delivered at different dosages.

METHOD

Eight children with developmental language disorder aged 8;0-10;10 (years;months) received 10 hr of explicit individualized intervention for morphosyntax delivered in 30-min individual sessions once per week for 20 weeks. Following at least four baseline probe tests, two grammatical targets per session received explicit instruction until they reached criterion (90%), when the next target was introduced. To control for session length and teaching episode density, either both targets received 20 teaching episodes per session or one target received 10 teaching episodes and the other 30. Maintenance testing of completed targets was also carried out.

RESULTS

Scores on probe tests post-intervention were significantly higher than during the baseline phase (d = 1.6) with no change during the baseline or maintenance phases. However, progress during the intervention phase was highly significant. One participant showed significantly faster progress with intervention, while one (with the lowest attention score) made little progress. When considering progress relative to cumulative intervention sessions, progress was faster with 30 teaching episodes per session and slower with 10. However, when cumulative teaching episodes were used as the predictor, all three within-session dosages showed very similar rates of progress, with the odds of a correct response increasing by 3.9% for each teaching episode. The targets that were achieved required an average of 40-60 teaching episodes.

CONCLUSIONS

With the exception of one participant, the individualized intervention was highly effective and efficient. Thus, the individualized target identification process and intervention method merit further research in a larger group of children. The cumulative number of teaching episodes per target provided across sessions appeared to be key. Thus, clinicians should aim for high teaching episode rates, particularly if the number of sessions is constrained. Otherwise, intervention scheduling can be flexible.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25996168.

Bayesian evidence synthesis as a flexible alternative to meta-analysis: A simulation study and empirical demonstration

Synthesizing results across multiple studies is a popular way to increase the robustness of scientific findings. The most well-known method for doing this is meta-analysis. However, because meta-analysis requires conceptually comparable effect sizes with the same statistical form, meta-analysis may not be possible when studies are highly diverse in terms of their research design, participant characteristics, or operationalization of key variables. In these situations, Bayesian evidence synthesis may constitute a flexible and feasible alternative, as this method combines studies at the hypothesis level rather than at the level of the effect size. This method therefore poses less constraints on the studies to be combined. In this study, we introduce Bayesian evidence synthesis and show through simulations when this method diverges from what would be expected in a meta-analysis to help researchers correctly interpret the synthesis results. As an empirical demonstration, we also apply Bayesian evidence synthesis to a published meta-analysis on statistical learning in people with and without developmental language disorder. We highlight the strengths and weaknesses of the proposed method and offer suggestions for future research.

Five Additional Evidence-Based Principles to Facilitate Grammar Development for Children With Developmental Language Disorder

PURPOSE

Because the development of grammatical forms is difficult for many children with developmental language disorder (DLD), language interventions often focus on supporting children's use of grammatical language. This article proposes five additional principles to those suggested by Fey et al. (2003) to facilitate the development of grammatical forms by children with DLD. Three of the five additional principles address the selection and presentation of linguistic contexts to be used with target grammatical forms (Principles 11-13); two principles encourage the incorporation of additional intervention components: auditory bombardment and explicit instruction (Principles 14 and 15, respectively).

METHOD

We present empirical evidence and, when available, describe the theoretical motivations to support each of the five additional principles. We then describe how we have integrated the five principles into 20- to 30-min intervention sessions that target regular past tense -ed, third-person singular -s, present progressive is/are verb+ing, or do/does questions for 4- to 8-year-olds with DLD. Each session includes four activities: sentence imitation, story retell, structured play, and auditory bombardment. We provide details of each activity, relevant materials, and illustrative examples that highlight the incorporation of each of the principles.

RESULTS

When targeting the development of grammatical forms in intervention, current evidence supports the use of a high degree of linguistic variability (Principle 11), the presentation of target forms in contexts that vary in difficulty (Principle 12), the presentation of target forms in sentences that vary in syntactic structure (Principle 13), the use of auditory bombardment (Principle 14), and the incorporation of explicit instruction (Principle 15). Clinicians can use these principles when targeting a range of grammatical forms in relatively short intervention sessions comprising a variety of activities.

CONCLUSIONS

This article encourages the employment of five additional principles into grammatical language intervention. Descriptions, materials, and examples demonstrate how the principles can all be addressed within a single intervention session.

What risk factors for Developmental Language Disorder can tell us about the neurobiological mechanisms of language development

Language is a complex multidimensional cognitive system that is connected to many neurocognitive capacities. The development of language is therefore strongly intertwined with the development of these capacities and their neurobiological substrates. Consequently, language problems, for example those of children with Developmental Language Disorder (DLD), are explained by a variety of etiological pathways and each of these pathways will be associated with specific risk factors. In this review, we attempt to link previously described factors that may interfere with language development to putative underlying neurobiological mechanisms of language development, hoping to uncover openings for future therapeutical approaches or interventions that can help children to optimally develop their language skills.

Impaired extraction and consolidation of morphological regularities in developmental dyslexia: A domain general deficit?

The current study examined whether adults with Developmental Dyslexia are impaired in learning linguistic regularities in a novel language, and whether this may be explained by a domain general deficit in the effect of sleep on consolidation. We compared online learning and offline consolidation of morphological regularities in individuals with Developmental Dyslexia (N = 40) and typical readers (N = 38). Participants learned to apply plural inflections to novel words based on morpho-phonological rules embedded in the input and learned to execute a finger motor sequence task. To test the effects of time and sleep on consolidation, participants were assigned into one of two sleep-schedule groups, trained in the evening or in the morning and tested 12 and 24 h later. Unlike typical readers, Dyslexic readers did not extract the morpho-phonological regularities during training and as a group they did not show offline gains in inflecting trained items 24 h after training, suggesting that the deficit in extraction of regularities during training may be related to the deficit in consolidation. The offline gains in dyslexic readers, were correlated with their prior phonological abilities, and were less affected by sleep than those of typical readers. Although no deficit was found in the consolidation of the motor task, dyslexic readers were again less successful in generating an abstract representation of the motor sequence, reflected in a difficulty to generalize the motor sequence knowledge acquired using one hand to the untrained hand. The results suggest that individuals with Developmental Dyslexia have a domain general deficit in extracting statistical regularities from an input. Within the language domain this deficit is reflected in reduced benefits of consolidation, particularly during sleep, perhaps due to reduced prior phonological abilities, which may impede the individual's ability to extract the linguistic regularities during and after training and thus constrain the consolidation process.

With or without Feedback?-How the Presence of Feedback Affects Processing in Children with Developmental Language Disorder

Language acquisition depends on the ability to process and learn probabilistic information, often through the integration of performance feedback. Children with developmental language disorder (DLD) have demonstrated weaknesses in both probabilistic learning and feedback processing, but the individual effects of each skill are poorly understood in this population. This study examined school-aged children with DLD (n = 29) and age- and gender-matched children with typical development (TD; n = 44) on a visual probabilistic classification learning task presented with and without feedback. In the feedback-based version of the task, children received performance feedback on a trial-by-trial basis during the training phase of the task. In the feedback-free version, children responded after seeing the correct choice marked with a green border and were not presented with feedback. Children with TD achieved higher accuracy than children with DLD following feedback-based training, while the two groups achieved similar levels of accuracy following feedback-free training. Analyses of event-related potentials (ERPs) provided insight into stimulus encoding processes. The feedback-free task was dominated by a frontal slow wave (FSW) and a late parietal component (LPC) which were not different between the two groups. The feedback-based task was dominated by a parietal slow wave (PSW) and an LPC, both of which were found to be larger in the TD than in the DLD group. In combination, results suggest that engagement with feedback boosts learning in children with TD, but not in children with DLD. When the need to process feedback is eliminated, children with DLD demonstrate behavioral and neurophysiological responses similar to their peers with TD.

Prosodic cues enhance infants' sensitivity to nonadjacent regularities

In language, grammatical dependencies often hold between items that are not immediately adjacent to each other. Acquiring these nonadjacent dependencies is crucial for learning grammar. However, there are potentially infinitely many dependencies in the language input. How does the infant brain solve this computational learning problem? Here, we demonstrate that while rudimentary sensitivity to nonadjacent regularities may be present relatively early, robust and reliable learning can only be achieved when convergent statistical and perceptual, specifically prosodic cues, are both present, helping the infant brain detect the building blocks that form a nonadjacent dependency. This study contributes to our understanding of the neural foundations of rule learning that pave the way for language acquisition.

Kindergarteners Use Cross-Situational Statistics to Infer the Meaning of Grammatical Elements

Many studies demonstrate that detecting statistical regularities in linguistic input plays a key role in language acquisition. Yet, it is unclear to what extent statistical learning is involved in more naturalistic settings, when young children have to acquire meaningful grammatical elements. In the present study, we address these points, by investigating whether statistical learning is involved in acquiring a morpho-syntactic structure from input that resembles natural languages more closely. We exposed 50 kindergarteners (M = 5 years, 5 months) to a miniature language in which they had to learn a grammatical marker that expressed number, and which could only be acquired on the basis of the distributional properties in the input. Half of the children performed an attention check during the experiment. Results show that young children are able to learn this meaning. We found no clear evidence that facilitating attention to the input increases learning performance.

Teaching foreign language grammar to primary-school children with developmental language disorder: A classroom-based intervention study

INTRODUCTION

Children with developmental language disorder (DLD) start learning foreign languages, usually English as a foreign language (EFL), at an increasingly young age. However, current scholarship lacks crucial insights into how children with DLD respond to language learning in classroom settings and how they can be supported in doing so. The purpose of this early efficacy study is to determine whether a business-as-usual curriculum or a new teaching method tailored to the specific needs of pupils with DLD results in (greater) progress in the foreign language (English) and in the school language (Dutch).

METHOD

The participants were 75 pupils with DLD in the last three years of primary school, learning EFL in special education in the Netherlands. The intervention group (n=41) received 12 lessons following the CodeTaal approach, including metalinguistic instruction of grammar rules, explicit cross-linguistic contrasts and multimodal interaction with the material. The control group (n=34) received their regular English lessons. The study used a pre- to post-test design and compared the performance of the two groups on a Grammaticality Judgment Task (GJT) in English and a narrative task in both English and Dutch.

RESULTS

Only the intervention group significantly improved in their ability to identify ungrammaticalities in English and generalised the learnt rules to new sentences. Although the performance on the GJT predicted accuracy of English narratives, neither group showed a significant decrease of error rates in English. In contrast, the accuracy of Dutch narratives showed improvement, but only in the intervention group. However, the effects were small and there was significant variability in responsiveness to the intervention.

CONCLUSION

We conclude that pupils with DLD are able to make progress in foreign language learning in a classroom setting if provided with adequate support.

Statistical Learning of Language: A Meta-Analysis Into 25 Years of Research

Statistical learning is a key concept in our understanding of language acquisition. Ample work has highlighted its role in numerous linguistic functions-yet statistical learning is not a unitary construct, and its consistency across different language properties remains unclear. In a meta-analysis of auditory-linguistic statistical learning research spanning the last 25 years, we evaluated how learning varies across different language properties in infants, children, and adults and surveyed the methodological trends in the literature. We found robust learning across stimuli (syllables, words, etc.) in infants, and across stimuli and structures (adjacent dependencies, non-adjacent dependencies, etc.) in adults, with larger effect sizes when multiple cues were present. However, the analysis also showed significant publication bias and revealed a tendency toward using a narrow range of simplified language properties, including in the strength of the transitional probabilities used during training. Bayes factor analyses revealed prevalent data insensitivity of moderators commonly hypothesized to impact learning, such as the amount of exposure and transitional probability strength, which contradict core theoretical assumptions in the field. Methodological factors, such as the tasks used at test, also significantly impacted effect sizes in adults and children, suggesting that choice of task may critically constrain current theories of how statistical learning operates. Collectively, our results suggest that auditory-linguistic statistical learning has the kind of robustness needed to play a foundational role in language acquisition, but that more research is warranted to reveal its full potential.

An Implicit-Explicit Framework for Intervention Methods in Developmental Language Disorder

PURPOSE

The growing interest in framing intervention approaches as either implicit or explicit calls for a discussion of what makes intervention approaches engage each of these learning systems, with the goal of achieving a shared framework. This tutorial presents evidence for the interaction between implicit and explicit learning systems, and it highlights the intervention characteristics that promote implicit or explicit learning as well as outcome measures that tap into implicit or explicit knowledge. This framework is then applied to eight common intervention approaches and notable combinations of approaches to unpack their differential engagement of implicit and explicit learning.

CONCLUSIONS

Many intervention characteristics (e.g., instructions, elicitation techniques, feedback) can be manipulated to move an intervention along the implicit-explicit continuum. Given the bias for using explicit learning strategies that develops throughout childhood and into adulthood, clinicians should be aware that most interventions (even those that promote implicit learning) will engage the explicit learning system. However, increased awareness of the implicit and explicit learning systems and their cognitive demands will allow clinicians to choose the most appropriate intervention for the target behavior.

Explicit Instructions Do Not Enhance Auditory Statistical Learning in Children With Developmental Language Disorder: Evidence From Event-Related Potentials

A current issue in psycholinguistic research is whether the language difficulties exhibited by children with developmental language disorder [DLD, previously labeled specific language impairment (SLI)] are due to deficits in their abilities to pick up patterns in the sensory environment, an ability known as statistical learning (SL), and the extent to which explicit learning mechanisms can be used to compensate for those deficits. Studies designed to test the compensatory role of explicit learning mechanisms in children with DLD are, however, scarce, and the few conducted so far have led to inconsistent results. This work aimed to provide new insights into the role that explicit learning mechanisms might play on implicit learning deficits in children with DLD by resorting to a new approach. This approach involved not only the collection of event-related potentials (ERPs), while preschool children with DLD [relative to typical language developmental (TLD) controls] were exposed to a continuous auditory stream made of the repetition of three-syllable nonsense words but, importantly, the collection of ERPs when the same children performed analogous versions of the same auditory SL task first under incidental (implicit) and afterward under intentional (explicit) conditions. In each of these tasks, the level of predictability of the three-syllable nonsense words embedded in the speech streams was also manipulated (high vs. low) to mimic natural languages closely. At the end of both tasks' exposure phase, children performed a two-alternative forced-choice (2-AFC) task from which behavioral evidence of SL was obtained. Results from the 2-AFC tasks failed to show reliable signs of SL in both groups of children. The ERPs data showed, however, significant modulations in the N100 and N400 components, taken as neural signatures of word segmentation in the brain, even though a detailed analysis of the neural responses revealed that only children from the TLD group seem to have taken advantage of the previous knowledge to enhance SL functioning. These results suggest that children with DLD showed deficits both in implicit and explicit learning mechanisms, casting doubts on the efficiency of the interventions relying on explicit instructions to help children with DLD to overcome their language difficulties.

The Role of Attention, Language Ability, and Language Experience in Children's Artificial Grammar Learning

PURPOSE

The current study examined the role of attention and language ability in nonverbal rule induction performance in a demographically diverse sample of school-age children.

METHOD

The participants included 43 English-speaking monolingual and 65 Spanish-English bilingual children between the ages of 5 and 9 years. Core Language Index standard scores from the Clinical Evaluation of Language Fundamentals-Fourth Edition indexed children's language skills. Rule induction was measured via a visual artificial grammar learning task. Two equally complex finite-state artificial grammars were used. Children learned one grammar in a low attention condition (where children were exposed to symbol sequences with no distractors) and another grammar in a high attention condition (where distractor symbols were presented around the perimeter of the target symbol sequences).

RESULTS

Overall, performance in the high attention condition was significantly worse than performance in the low attention condition. Children with robust language skills performed significantly better in the high attention condition than children with weaker language skills. Despite group differences in socioeconomic status, English language skills, and nonverbal intelligence, monolingual and bilingual children performed similarly to each other in both conditions.

CONCLUSION

The results suggest that the ability to extract rules from visual input is attenuated by the presence of competing visual information and that language ability, but not bilingualism, may influence rule induction.

The role of Function Words to build syntactic knowledge in French-speaking children

The question of how children learn Function Words (FWs) is still a matter of debate among child language researchers. Are early multiword utterances based on lexically specific patterns or rather abstract grammatical relations? In this corpus study, we analyzed FWs having a highly predictable distribution in relation to Mean Length Utterance (MLU) an index of syntactic complexity in a large naturalistic sample of 315 monolingual French children aged 2 to 4 year-old. The data was annotated with a Part Of Speech Tagger (POS-T), belonging to computational tools from CHILDES. While eighteen FWs strongly correlated with MLU expressed either in word or in morpheme, stepwise regression analyses showed that subject pronouns predicted MLU. Factor analysis yielded a bifactor hierarchical model: The first factor loaded sixteen FWs among which eight had a strong developmental weight (third person singular verbs, subject pronouns, articles, auxiliary verbs, prepositions, modals, demonstrative pronouns and plural markers), whereas the second factor loaded complex FWs (possessive verbs and object pronouns). These findings challenge the lexicalist account and support the view that children learn grammatical forms as a complex system based on early instead of late structure building. Children may acquire FWs as combining words and build syntactic knowledge as a complex abstract system which is not innate but learned from multiple word input sentences context. Notably, FWs were found to predict syntactic development and sentence complexity. These results open up new perspectives for clinical assessment and intervention.

Statistical word learning in Catalan-Spanish and English-speaking children with and without developmental language disorder

BACKGROUND

A growing body of work shows that children with developmental language disorder (DLD) perform poorly on statistical word learning (SWL) tasks, consistent with the predictions of the Procedural Deficit Hypothesis that predicts that procedural memory is impaired in DLD. To date, however, SWL performance has not been compared across linguistically heterogeneous populations of children with DLD.

AIMS

To compare SWL performance in a group of age, sex and non-verbal IQ-matched Catalan-Spanish and English-speaking children with and without DLD.

METHODS & PROCEDURES

Two cohorts of children: (1) 35 Catalan-Spanish-speaking children with DLD (M_age = 8;7 years) and 35 age/sex-matched typical developing (TD) children (M_age = 8;9 years), and (2) 24 English-speaking children with DLD (M_age = 9;1 years) and 19 age/sex matched TD controls (M_age = 8;9 years) completed the tone version of a SWL task from Evans et al. (2009). Children listened to a tone language in which transitional probabilities within tone words were higher than those between words.

OUTCOMES & RESULTS

For both Catalan-Spanish and English cohorts, overall performance for the children with DLD was poorer than that of the TD controls regardless of the child's native language. Item analysis revealed that children with DLD had difficulty tracking statistical information and using transitional probability to discover tone word boundaries within the input. For both the Catalan-Spanish and English-speaking children, SWL accounted for a significant amount of unique variance in Receptive and Expressive vocabulary. Likelihood ratio analysis revealed that for both Catalan-Spanish and English cohorts, children having performance ≤ 45% on the SWL task had an extremely high degree of likelihood of having DLD. The analysis also revealed that for the Catalan-Spanish and English-speaking children, scores of ≥ 75% and ≥ 70%, respectively, were highly likelihood to be children with normal language abilities.

CONCLUSIONS & IMPLICATIONS

The findings add to a pattern suggesting that SWL is a mechanism that children rely on to acquire vocabulary. The results also suggest that SWL deficits, in particular when combined with other measures, may be a reliable diagnostic indicator for children with DLD regardless of the child's native language, and whether or not the child is bilingual or monolingual.

WHAT THIS PAPER ADDS

What is already known on the subject Although there is some disagreement, a small but growing body of work suggests that deficits in procedural memory, as measured either by motor sequencing (Serial Reaction Time-SRT) or SWL tasks, may be part of the deficit profile of children with DLD. To date, studies have not examined SWL across linguistically heterogeneous populations of children with DLD to determine if it is a unique clinical marker of the disorder. What this paper adds to existing knowledge The results show that children with DLD, regardless of their native language, or whether the child is bi- or monolingual, have difficulties on SWL tasks, and that these deficits are linked to severity of the language disorder. Taken together, these results indicate that procedural memory deficits may be a core feature of DLD. This suggests that statistical-learning tasks using tone stimuli can also advance our understanding of statistical-learning abilities in children with DLD more globally. What are the potential or actual clinical implications of this work? The current study shows that statistical-learning tasks using tone stimuli can be used in conjunction with standardized assessment measures to differentiate children with DLD from children with typical language ability.

The Value of Statistical Learning to Cognitive Network Science

To study the human mind is to consider the nature of associations-how are they learned, what are their constituent parts, and how can they be severed or adjusted? The manipulation of associations stands as a pillar of statistical learning (SL) research, which strongly suggests that processes as diverse as word segmentation, learning of grammatical patterns, and event perception can be explained by the learner's sensitivity to simple temporal dependencies (among other regularities). Used to determine the edges of a network, associations are similarly crucial to consider when quantifying the graph-theoretical properties of various cognitive systems. With this point of convergence in mind, the present work reaffirms the unique value of network science in illuminating the broad-level architectures of complex cognitive systems. However, I also describe how insights from the SL literature, coupled with insights from psycholinguistics more broadly, offer a strong theoretical backbone upon which we can develop and study networks that reflect, as closely as possible, the psychological realities of learning.

Unraveling the Interconnections Between Statistical Learning and Dyslexia: A Review of Recent Empirical Studies

One important aspect of human cognition involves the learning of structured information encountered in our environment, a phenomenon known as statistical learning. A growing body of research suggests that learning to read print is partially guided by learning the statistical contingencies existing between the letters within a word, and also between the letters and sounds to which the letters refer. Research also suggests that impairments to statistical learning ability may at least partially explain the difficulties experienced by individuals diagnosed with dyslexia. However, the findings regarding impaired learning are not consistent, perhaps partly due to the varied use of methodologies across studies - such as differences in the learning paradigms, stimuli used, and the way that learning is assessed - as well as differences in participant samples such as age and extent of the learning disorder. In this review, we attempt to examine the purported link between statistical learning and dyslexia by assessing a set of the most recent and relevant studies in both adults and children. Based on this review, we conclude that although there is some evidence for a statistical learning impairment in adults with dyslexia, the evidence for an impairment in children is much weaker. We discuss several suggestive trends that emerge from our examination of the research, such as issues related to task heterogeneity, possible age effects, the role of publication bias, and other suggestions for future research such as the use of neural measures and a need to better understand how statistical learning changes across typical development. We conclude that no current theoretical framework of dyslexia fully captures the extant research findings on statistical learning.

Online Statistical Learning in Developmental Language Disorder

Purpose: The vulnerability of statistical learning (SL) in developmental language disorder (DLD) has mainly been demonstrated with metacognitive offline measures which give little insight into the more specific nature and timing of learning. Our aims in this study were to test SL in children with and without DLD with both online and offline measures and to compare the efficiency of SL in the visual and acoustic modalities in DLD. Method: We explored SL in school-age children with and without DLD matched on age and sex (n = 36). SL was investigated with the use of acoustic verbal and visual nonverbal segmentation tasks relying on online (reaction times and accuracy) and offline (two-alternative forced choice, 2AFC and production) measures. Results: In online measures, learning was evident in both groups in both the visual and acoustic modalities, while offline measures showed difficulties in DLD. The visual production task showed a significant learning effect in both groups, while the visual two-alternative forced choice (2AFC) and the two acoustic offline tasks only showed evidence of learning in the control group. The comparison of learning indices revealed an SL impairment in DLD, which is present in both modalities. Conclusions: Our findings suggest that children with DLD are comparable to typically developing (TD) children in their ability to extract acoustic verbal and visual nonverbal patterns that are cued only by transitional probabilities in online tasks, but they show impairments on metacognitive measures of learning. The pattern of online and offline measures implies that online tests can be more sensitive and valid indices of SL than offline tasks, and the combined use of different measures provides a better picture of learning efficiency, especially in groups where metacognitive tasks are challenging.

Simulating the Acquisition of Verb Inflection in Typically Developing Children and Children With Developmental Language Disorder in English and Spanish

Children with developmental language disorder (DLD) have significant deficits in language ability that cannot be attributed to neurological damage, hearing impairment, or intellectual disability. The symptoms displayed by children with DLD differ across languages. In English, DLD is often marked by severe difficulties acquiring verb inflection. Such difficulties are less apparent in languages with rich verb morphology like Spanish and Italian. Here we show how these differential profiles can be understood in terms of an interaction between properties of the input language, and the child's ability to learn predictive relations between linguistic elements that are separated within a sentence. We apply a simple associative learning model to sequential English and Spanish stimuli and show how the model's ability to associate cues occurring earlier in time with later outcomes affects the acquisition of verb inflection in English more than in Spanish. We relate this to the high frequency of the English bare form (which acts as a default) and the English process of question formation, which means that (unlike in Spanish) bare forms frequently occur in third-person singular contexts. Finally, we hypothesize that the pro-drop nature of Spanish makes it easier to associate person and number cues with the verb inflection than in English. Since the factors that conspire to make English verb inflection particularly challenging for learners with weak sequential learning abilities are much reduced or absent in Spanish, this provides an explanation for why learning Spanish verb inflection is relatively unaffected in children with DLD.

Deficits of Learning in Procedural Memory and Consolidation in Declarative Memory in Adults With Developmental Language Disorder

Purpose This study examined procedural and declarative learning and consolidation abilities in adults with developmental language disorder (DLD) relative to their typical language (TD) peers. Method A total of 100 young adults (age 18-24 years) with (n = 21) and without (n = 79) DLD participated across two sites. Performance measures on a recognition memory task and a serial reaction time task were used to assess declarative and procedural memory, respectively. Performance was measured shortly after learning (8 a.m.) and again after a 12-hr, overnight delay (8 a.m.). Results Linear mixed-effects modeling was used to examine the effects of time and group membership on task performance. For the serial reaction time task, there were significant effects of group (TD > DLD) and time (Day 1 > Day 2), but no interaction between them. For the recognition memory task, there was a significant interaction between group and time, driven by overnight gains in the TD group, combined with stable performance across days by those with DLD. Conclusions In procedural memory, adults with DLD demonstrate a learning deficit relative to adults without DLD, but appear to have comparable retention of learned information. In declarative memory, adults with DLD demonstrate a deficit in the overnight enhancement of memory retrieval, despite typical-like learning exhibited when tested shortly after encoding. Supplemental Material https://doi.org/10.23641/asha.13626485.

Predictive Processing and Developmental Language Disorder

Purpose Research in the cognitive and neural sciences has situated predictive processing-the anticipation of upcoming percepts-as a dominant function of the brain. The purpose of this article is to argue that prediction should feature more prominently in explanatory accounts of sentence processing and comprehension deficits in developmental language disorder (DLD). Method We evaluate behavioral and neurophysiological data relevant to the theme of prediction in early typical and atypical language acquisition and processing. Results Poor syntactic awareness-attributable, in part, to an underlying statistical learning deficit-is likely to impede syntax-based predictive processing in children with DLD, conferring deficits in spoken sentence comprehension. Furthermore, there may be a feedback cycle in which poor syntactic awareness impedes children's ability to anticipate upcoming percepts, and this, in turn, makes children unable to improve their syntactic awareness on the basis of prediction error signals. Conclusion This article offers a refocusing of theory on sentence processing and comprehension deficits in DLD, from a difficulty in processing and integrating perceived syntactic features to a difficulty in anticipating what is coming next.

Statistical Learning and Language Impairments: Toward More Precise Theoretical Accounts

Statistical-learning (SL) theory offers an experience-based account of typical and atypical spoken and written language acquisition. Recent work has provided initial support for this view, tying individual differences in SL abilities to linguistic skills, including language impairments. In the current article, we provide a critical review of studies testing SL abilities in participants with and without developmental dyslexia and specific language impairment and discuss the directions that this field of research has taken so far. We identify substantial vagueness in the demarcation lines between different theoretical constructs (e.g., “statistical learning,” “implicit learning,” and “procedural learning”) as well as in the mappings between experimental tasks and these theoretical constructs. Moreover, we argue that current studies are not designed to contrast different theoretical approaches but rather test singular confirmatory predictions without including control tasks showing normal performance. We end by providing concrete suggestions for how to advance research on SL deficits in language impairments.

Can children with DLD acquire a second language in a foreign-language classroom? Effects of age and cross-language relationships

There is a growing pressure to teach foreign languages as early as possible, and children with Developmental Language Disorder (DLD) are not immune from these pressures. However, current scholarship lacks crucial insights into how children with DLD respond to L2 learning with minimal (classroom) exposure. In this paper, we report the results of a longitudinal study tracing the development of L1 Russian and English as a Foreign Language (EFL) skills in a group of learners with DLD (age of EFL onset: 7;9-12;1). The performance of the DLD group was compared to that of typically-developing controls, matched for classroom EFL exposure. Proficiency in English and Russian was measured three times (after one, one-and-a-half and two years of EFL instruction). At Time 1, there were no significant differences between groups on the EFL measures, but the performance of the typically-developing children significantly improved with time, and that of the DLD group did not. In the DLD group, age of EFL onset was positively related to English receptive vocabulary size. The relation between L1 and L2 proficiency in the DLD group was weaker than in the comparison group. This pattern is probably due to the floor performance of the DLD group in the grammatical domain, but may also indicate that the disorder affects cross-language transfer in the vulnerable domains.

Statistical Learning in Late Talkers and Normal Peers

Background:

Late talkers (LTs) are children under three with poor vocabularies and no developmental problems. Statistical learning (SL) is defined as processing or learning patterns of environmental stimuli, for example, spoken language, music, or motor, that will unfold in time. We hypothesize if some LTs outgrow as developmental language disorder, they might be identified using SL tasks at the onset. We aimed to find any correlation between language measures and SL outcomes in LTs and normal children (NC).

Materials and Methods:

Sixteen pairs of LTs and NCs were recruited using a convenient sampling method from day-care centers and speech therapy clinics of the Comprehensive Center for Child Development in Isfahan city, Iran. Visual sequences presented using Habit software version 2.2.4. Children’s eye movements to visual sequences were monitored, and their reaction times and the number of anticipatory looks were analyzed offline. The language measures were determined in the free-play context.

Results:

Results indicated no significant correlation between SL and language measures and no difference observed in SL between the groups (P = 0.73).

Conclusions:

The results may refer to no overt correlation between SL and delayed overall linguistic measures along with inadequate samples, children’s fatigue, or insufficiency of the visual task in presenting SL.

Is that a pibu or a pibo? Children with reading and language deficits show difficulties in learning and overnight consolidation of phonologically similar pseudowords

Word learning is critical for the development of reading and language comprehension skills. Although previous studies have indicated that word learning is compromised in children with reading disability (RD) or developmental language disorder (DLD), it is less clear how word learning difficulties manifest in children with comorbid RD and DLD. Furthermore, it is unclear whether word learning deficits in RD or DLD include difficulties with offline consolidation of newly learned words. In the current study, we employed an artificial lexicon learning paradigm with an overnight design to investigate how typically developing (TD) children (N = 25), children with only RD (N = 93), and children with both RD and DLD (N = 34) learned and remembered a set of phonologically similar pseudowords. Results showed that compared to TD children, children with RD exhibited: (i) slower growth in discrimination accuracy for cohort item pairs sharing an onset (e.g. pibu‐pibo), but not for rhyming item pairs (e.g. pibu‐dibu); and (ii) lower discrimination accuracy for both cohort and rhyme item pairs on Day 2, even when accounting for differences in Day 1 learning. Moreover, children with comorbid RD and DLD showed learning and retention deficits that extended to unrelated item pairs that were phonologically dissimilar (e.g. pibu‐tupa), suggestive of broader impairments compared to children with only RD. These findings provide insights into the specific learning deficits underlying RD and DLD and motivate future research concerning how children use phonological similarity to guide the organization of new word knowledge.

Statistical learning for vocal sequence acquisition in a songbird

Birdsong is a learned communicative behavior that consists of discrete acoustic elements (“syllables”) that are sequenced in a controlled manner. While the learning of the acoustic structure of syllables has been extensively studied, relatively little is known about sequence learning in songbirds. Statistical learning could contribute to the acquisition of vocal sequences, and we investigated the nature and extent of sequence learning at various levels of song organization in the Bengalese finch, Lonchura striata var. domestica. We found that, under semi-natural conditions, pupils (sons) significantly reproduced the sequence statistics of their tutor’s (father’s) songs at multiple levels of organization (e.g., syllable repertoire, prevalence, and transitions). For example, the probability of syllable transitions at “branch points” (relatively complex sequences that are followed by multiple types of transitions) were significantly correlated between the songs of tutors and pupils. We confirmed the contribution of learning to sequence similarities between fathers and sons by experimentally tutoring juvenile Bengalese finches with the songs of unrelated tutors. We also discovered that the extent and fidelity of sequence similarities between tutors and pupils were significantly predicted by the prevalence of sequences in the tutor’s song and that distinct types of sequence modifications (e.g., syllable additions or deletions) followed distinct patterns. Taken together, these data provide compelling support for the role of statistical learning in vocal production learning and identify factors that could modulate the extent of vocal sequence learning.

The word learning profile of adults with developmental language disorder

BACKGROUND AND AIMS

Previous investigations of word learning problems among people with developmental language disorder suggest that encoding, not retention, is the primary deficit. We aimed to replicate this finding; test the prediction that word form, not the linking of form to referent, is particularly problematic; and determine whether women with developmental language disorder are better word learners than men with developmental language disorder.

METHODS

Twenty adults with developmental language disorder and 19 age-, sex-, and education-matched peers with typical language development attempted to learn 15 words by retrieval practice. Their retention was measured one day-, one week-, and one month after training.

RESULTS

The participants with developmental language disorder required more exposures to the word-referent pairs than the participants with typical language development to reach mastery. While training to mastery, they made more errors in word form production, alone or in combination with errors in linking forms to the correct referents, but the number of no attempts and pure link errors did not differ by group. Women demonstrated stronger retention of the words than men at all intervals. The developmental language disorder and typical language development groups did not differ at the one-day- and one-month retention intervals but the developmental language disorder group was weaker at the one-week interval. Review via retrieval practice at the one-day and one-week interval enhanced retention at the one-month interval; the review at one week was more beneficial than the review at one day. Women benefitted more from the review opportunities than men but the developmental language disorder and typical language development groups did not differ.

CONCLUSIONS

Adults with developmental language disorder present with weaknesses in the encoding of new words but retention is a relative strength. Encoding word forms is especially challenging but encoding word-to-referent links is not. We interpret this profile, and the evidence of a female advantage, as consistent with the Procedural Circuit Deficit Hypothesis.

IMPLICATIONS

When treating a client with developmental language disorder whose goal is to increase vocabulary knowledge, the interventionist should anticipate the need for multiple exposures to new words within activities that highlight the forms of the words and support their memory and production. Periodic review should serve to support long-term retention.

Speech-language development as proceduralization and skill learning: Implications for assessment and intervention

PURPOSE

This article considers how speech-language development can be viewed as proceduralization and skill learning. Viewing speech-language development in this way has important implications for the assessment and treatment of individuals with speech-language disorders.

METHOD

Topics discussed are Ullman's (2016) distinction between the procedural and declarative memory systems, speech-language development as proceduralization and skill learning, and implications for assessment and intervention.

CONCLUSION

Norm-referenced measures provide a good measure of deliberative speech-language processes whereas social conversations and discourses about familiar topics with familiar listeners provide the best indication of proceduralized speech-language processes. Intervention goals and planning need to consider which speech-language operations should be proceduralized and which ones will primarily require deliberative processing. Additional research and clinical application of these ideas are clearly needed to develop more precise criteria to define the line of demarcation between deliberative and proceduralized speech-language processes.

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 and Developmental Differences in Distributional Learning

Purpose

This study examined whether children and adults with developmental language disorder (DLD) could use distributional information in an artificial language to learn about grammatical category membership similarly to their typically developing (TD) peers and whether developmental differences existed within and between DLD and TD groups.

Method

Sixteen children ages 7-9 with DLD, 26 age-matched TD children, 17 college students with DLD, and 17 TD college students participated in this task. We used an artificial grammar learning paradigm in which participants had to use knowledge of category membership to determine the acceptability of test items that they had not heard during a training phase.

Results

Individuals with DLD performed similarly to TD peers in distinguishing grammatical from ungrammatical combinations, with no differences between age groups. The order in which items were heard at test differentially affected child versus adult participants and showed a relation with attention and phonological working memory as well.

Conclusion

Differences in ratings between grammatical and ungrammatical items in this task suggest that individuals with DLD can form grammatical categories from novel input and more broadly use distributional information. Differences in order effects suggest a developmental timeline for sensitivity to updating distributional information.

Behind the Scenes of Developmental Language Disorder: Time to Call Neuropsychology Back on Stage

Although the Developmental Language Disorder (DLD), also known as Specific Language Impairment in children has been the focus of unceasing scientific attention for decades, the nature and mechanisms of this disorder remain unclear. Most importantly, we still cannot reliably identify children requiring urgent intervention among other ‘late talkers’ at an early age and understand the high prevalence of comorbidity with psychiatric phenomena such as Autism Spectrum Disorder. One of the main reasons for this is the traditional ‘diagnosis-by-exclusion,’ resulting in heterogeneity of the DLD population. This paper proposes an alternative approach to the diagnosis, treatment and research of DLD, claiming that it is these children’s multiple deficits in neuropsychological development, which impede the spontaneous acquisition of their first language. Specifically, this review of the state-of-the-art in DLD research demonstrates deep and systematic interconnections between the speech and other higher cognitive functions developing in early childhood, including perception, attention and executive functions. In the proposed framework, speech is, therefore, considered as one of neuropsychological abilities, and the delay in its development is explained by other neuropsychological deficits, resulting in highly individual clinical profiles. By considering DLD as a complex neuropsychological syndrome, whose successful treatment depends on a holistic approach to diagnosis and intervention, we may significantly increase the efficacy of speech therapy, and also better understand the flexibility of the developing brain, its compensatory mechanisms and hence the comorbidity of DLD with psychiatric symptoms. Implications for using this paradigm in future scientific research are discussed.

Prevalence of Publication Bias Tests in Speech, Language, and Hearing Research

PURPOSE

The purpose of this research note is to systematically document the extent that researchers who publish in American Speech-Language-Hearing Association (ASHA) journals search for and include unpublished literature in their meta-analyses and test for publication bias.

METHOD

This research note searched all ASHA peer-reviewed journals for published meta-analyses and reviewed all qualifying articles for characteristics related to the acknowledgment and assessment of publication bias.

RESULTS

Of meta-analyses published in ASHA journals, 75% discuss publication in some form; however, less than 50% test for publication bias. Further, only 38% (n = 11) interpreted the findings of these tests.

CONCLUSION

Findings reveal that more attention is needed to the presence and impact of publication bias. This research note concludes with 5 recommendations for addressing publication bias.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.7268648.

Distributional Cues to Language Learning in Children With Intellectual Disabilities

Purpose

In typical development, distributional cues-patterns in input-are related to language acquisition processes. Statistical and implicit learning refer to the utilization of such cues. In children with intellectual disability, much less is known about the extent to which distributional cues are harnessed in mechanisms of language learning.

Method

This tutorial presents what is known about the process of language learning in children with language impairments associated with different sources of intellectual disability: Williams syndrome, autism spectrum disorder, Down syndrome, and fragile X syndrome.

Results

A broad view is taken on distributional cues relevant to language learning, including statistical learning (e.g., transitional probabilities) and other patterns that support lexical acquisition (e.g., sensitivities to sound patterns, cross-situational word learning) or relate to syntactic development (e.g., nonadjacent dependencies).

Conclusions

Critical gaps in the literature are highlighted. Research in this area is especially limited for Down syndrome and fragile X syndrome. Future directions for taking learning theories into account in interventions for children with intellectual disability are discussed, with a focus on the importance of language input.