The P-chain: relating sentence production and its disorders to comprehension and acquisition

This article introduces the P-chain, an emerging framework for theory in psycholinguistics that unifies research on comprehension, production and acquisition. The framework proposes that language processing involves incremental prediction, which is carried out by the production system. Prediction necessarily leads to prediction error, which drives learning, including both adaptive adjustment to the mature language processing system as well as language acquisition. To illustrate the P-chain, we review the Dual-path model of sentence production, a connectionist model that explains structural priming in production and a number of facts about language acquisition. The potential of this and related models for explaining acquired and developmental disorders of sentence production is discussed.     

Defining language impairments in a subgroup of children with autism spectrum disorder

Autism spectrum disorder(ASD) is diagnosed on the basis of core impairments in pragmatic language skills, which are found across all ages and subtypes. In contrast, there is significant heterogeneity in language phenotypes, ranging from nonverbal to superior linguistic abilities, as defined on standardized tests of vocabulary and grammatical knowledge. The majority of children are verbal but impaired in language, relative to age-matched peers. One hypothesis is that this subgroup has ASD and co-morbid specific language impairment(SLI). An experiment was conducted comparing children with ASD to children with SLI and typically developing controls on aspects of language processing that have been shown to be impaired in children with SLI: repetition of nonsense words. Patterns of performance among the children with ASD and language impairment were similar to those with SLI, and contrasted with the children with ASD and no language impairment and typical controls, providing further evidence for the hypothesis that a subgroup of children with ASD has co-morbid SLI. The findings are discussed in the context of brain imaging studies that have explored the neural bases of language impairment in ASD and SLI, and overlap in the genes associated with elevated risk for these disorders.     

Gas Law for the Classroom

The author provides information on how science teachers can write science literacy objectives that help English language learners (ELLs) develop the scientific literacy needed for academic success in the science classroom. The article offers suggestions on how teachers can determine the vocabulary, language functions, and sentence structures that their students need to engage in critical thinking in science. An approach for collaboration with students' English as a second language (ESL) teacher is discussed.     

Memory and Language in Middle Childhood in Individuals with a History of Specific Language Impairment

This study reports on the sensitivity of sentence repetition as a marker of specific language impairment (SLI) in different subgroups of children in middle childhood and examines the role of memory and grammatical knowledge in the performance of children with and without language difficulties on this task. Eleven year old children, 197 with a history of SLI and 75 typically developing (TD) peers were administered sentence repetition, phonological short term memory (PSTM) and grammatical morphology tasks. Children with a history of SLI were divided into four subgroups: specific language impairment, non-specific language impairment, low cognition with resolved language and resolved. Performance on the sentence repetition task was significantly impaired in all four subgroups of children with a history of SLI when compared to their age peers. Regression analyses revealed grammatical knowledge was predictive of performance for TD children and children with a history of SLI. However, memory abilities were significantly predictive of sentence repetition task performance for children with a history of SLI only. Processes involved in sentence repetition are more taxing of PSTM for individuals with a history of SLI in middle childhood in a way that does not appear to be the case for TD children.     

Beyond the sentence given

A central and influential idea among researchers of language is that our language faculty is organized according to Fregean compositionality, which states that the meaning of an utterance is a function of the meaning of its parts and of the syntactic rules by which these parts are combined. Since the domain of syntactic rules is the sentence, the implication of this idea is that language interpretation takes place in a two-step fashion. First, the meaning of a sentence is computed. In a second step, the sentence meaning is integrated with information from prior discourse, world knowledge, information about the speaker and semantic information from extra-linguistic domains such as co-speech gestures or the visual world. Here, we present results from recordings of event-related brain potentials that are inconsistent with this classical two-step model of language interpretation. Our data support a one-step model in which knowledge about the context and the world, concomitant information from other modalities, and the speaker are brought to bear immediately, by the same fast-acting brain system that combines the meanings of individual words into a message-level representation. Underlying the one-step model is the immediacy assumption, according to which all available information will immediately be used to co-determine the interpretation of the speaker's message. Functional magnetic resonance imaging data that we collected indicate that Broca's area plays an important role in semantic unification. Language comprehension involves the rapid incorporation of information in a 'single unification space', coming from a broader range of cognitive domains than presupposed in the standard two-step model of interpretation.     

Relationship Between Respiratory Sinus Arrhythmia, Heart Period, and Caregiver-Reported Language and Cognitive Delays in Children with Autism Spectrum Disorders

The present study examines the relationship between autonomic activity and cognitive/language delays in children with autism spectrum disorder (ASD). Baseline levels of respiratory sinus arrhythmia (RSA) and heart period (HP) were assessed in 23 4–7-year old children diagnosed with ASD. The relationship between RSA, HP, and ASD behavioral symptoms was examined. Similar to prior studies on typically developing children, lower basal RSA was related to more caregiver-reported language and cognitive delays, and to the lack of language.     

What Factors Are Associated with Positive Effects of Dog Ownership in Families with Children with Autism Spectrum Disorder? The Development of the Lincoln Autism Pet Dog Impact Scale

Scientific literature exploring the value of assistance dogs to children with autism spectrum disorder (ASD) is rapidly emerging. However, there is comparably less literature reporting the effects of pet (as opposed to assistance) dogs to these children. In particular, there are no known validated scales which assess how children may alter their behaviours in the presence of the dog, to evaluate the efficacy of pet dogs to these families. Additionally, given the highly individualised nature of ASD it is likely that some children and families gain more benefits from dog ownership than others, yet no research has reported the effect of individual differences. This pilot study reports the development of a 28-item scale based on the perceived impact of a pet dog on a child with autism by parents (Lincoln Autism Pet Dog Impact Scale—LAPDIS). The scale is comprised of three mathematically derived factors: Adaptability, Social Skills and Conflict Management. We assessed how individual differences (aspects) may be associated with scores on these three factors. Family Aspects and Dog Aspects were not significantly associated with ratings on the three factors, but Child Aspects (including: contact with horses, child age, disability level and language abilities) were related to impact of the dog on all factors. Training Aspects were related to scores on Social Skills (formal training with children with ASD and dogs and attendance at PAWS workshops run by Dogs for Good). These results suggest that individual differences associated with the child and the training approach may be important considerations for a positive impact from dog ownership on families with children with ASD. Differences in family features and the dog may not be so important, but may be worthy of further investigations given the early stage of development in this field.     

孤独症谱系障碍儿童早期神经发育水平和智能特征分析

目的:探讨孤独症谱系障碍(Autism spectrum disorder,ASD)儿童早期神经发育水平及智能分区特征,为提高ASD的早期识别和诊断提供理论依据.方法:运用Gesell发育评估量表对18月龄至48月龄以内的27例ASD患儿和30例发育迟缓(Mental retardation,MR)患儿的发育商(Dev...     

Effect of Familiarity on Reward Anticipation in Children with and without Autism Spectrum Disorders

Background

Previous research on the reward system in autism spectrum disorders (ASD) suggests that children with ASD anticipate and process social rewards differently than typically developing (TD) children—but has focused on the reward value of unfamiliar face stimuli. Children with ASD process faces differently than their TD peers. Previous research has focused on face processing of unfamiliar faces, but less is known about how children with ASD process familiar faces. The current study investigated how children with ASD anticipate rewards accompanied by familiar versus unfamiliar faces.

Methods

The stimulus preceding negativity (SPN) of the event-related potential (ERP) was utilized to measure reward anticipation. Participants were 6- to 10-year-olds with (N = 14) and without (N = 14) ASD. Children were presented with rewards accompanied by incidental face or non-face stimuli that were either familiar (caregivers) or unfamiliar. All non-face stimuli were composed of scrambled face elements in the shape of arrows, controlling for visual properties.

Results

No significant differences between familiar versus unfamiliar faces were found for either group. When collapsing across familiarity, TD children showed larger reward anticipation to face versus non-face stimuli, whereas children with ASD did not show differential responses to these stimulus types. Magnitude of reward anticipation to faces was significantly correlated with behavioral measures of social impairment in the ASD group.

Conclusions

The findings do not provide evidence for differential reward anticipation for familiar versus unfamiliar face stimuli in children with or without ASD. These findings replicate previous work suggesting that TD children anticipate rewards accompanied by social stimuli more than rewards accompanied by non-social stimuli. The results do not support the idea that familiarity normalizes reward anticipation in children with ASD. Our findings also suggest that magnitude of reward anticipation to faces is correlated with levels of social impairment for children with ASD.     

Clinical Characteristics of Children with Autism Spectrum Disorder and Co-Occurring Epilepsy

Objectives

To estimate the prevalence of epilepsy in children with Autism Spectrum Disorder (ASD) and to determine the demographic and clinical characteristics of children with ASD and epilepsy in a large patient population.

Methods

Cross-sectional study using four samples of children with ASD for a total of 5,815 participants with ASD. The prevalence of epilepsy was estimated from a population-based sample. Children with and without epilepsy were compared on demographic and clinical characteristics. Multivariate logistic regression was used to examine the association between demographic and clinical characteristics and epilepsy.

Results

The average prevalence of epilepsy in children with ASD 2–17 years was 12.5%; among children aged 13 years and older, 26% had epilepsy. Epilepsy was associated with older age, lower cognitive ability, poorer adaptive and language functioning, a history of developmental regression and more severe ASD symptoms. The association between epilepsy and the majority of these characteristics appears to be driven by the lower IQ of participants with epilepsy. In a multivariate regression model, only age and cognitive ability were independently associated with epilepsy. Children age 10 or older had 2.35 times the odds of being diagnosed with epilepsy (p<.001) and for a one standard deviation increase in IQ, the odds of having epilepsy decreased by 47% (p<.001).

Conclusion

This is among the largest studies to date of patients with ASD and co-occurring epilepsy. Based on a representative sample of children with ASD, the average prevalence of epilepsy is approximately 12% and reaches 26% by adolescence. Independent associations were found between epilepsy and older age and lower cognitive ability. Other risk factors, such as poor language and developmental regression, are not associated with epilepsy after controlling for IQ. These findings can help guide prognosis and alert clinicians to patients with ASD who are at increased risk for epilepsy.     

What does CNTNAP2 reveal about autism spectrum disorder?

Autism spectrum disorder (ASD) is a phenotypically and genetically heterogeneous condition characterized by the presence of repetitive/restrictive behaviors and variable deficits in language and social behavior. Many genes predisposing an individual to ASD have been identified, and understanding the causal disease mechanism(s) is critical to be able to develop treatments. Neurobiological, genetic, and imaging data provide strong evidence for the CNTNAP2 gene as a risk factor for ASD and related neurodevelopmental disorders. This review discusses the clinical genetics and current understanding of the biology of CNTNAP2 as related to ASD and illustrates how the integration of multiple research approaches, from human studies to animal models, converge to inform functional biology focused on novel treatment development.     

Echoes of the spoken past: how auditory cortex hears context during speech perception

What do we hear when someone speaks and what does auditory cortex (AC) do with that sound? Given how meaningful speech is, it might be hypothesized that AC is most active when other people talk so that their productions get decoded. Here, neuroimaging meta-analyses show the opposite: AC is least active and sometimes deactivated when participants listened to meaningful speech compared to less meaningful sounds. Results are explained by an active hypothesis-and-test mechanism where speech production (SP) regions are neurally re-used to predict auditory objects associated with available context. By this model, more AC activity for less meaningful sounds occurs because predictions are less successful from context, requiring further hypotheses be tested. This also explains the large overlap of AC co-activity for less meaningful sounds with meta-analyses of SP. An experiment showed a similar pattern of results for non-verbal context. Specifically, words produced less activity in AC and SP regions when preceded by co-speech gestures that visually described those words compared to those words without gestures. Results collectively suggest that what we ‘hear’ during real-world speech perception may come more from the brain than our ears and that the function of AC is to confirm or deny internal predictions about the identity of sounds.     

Neural signatures of syntactic variation in speech planning

Planning to speak is a challenge for the brain, and the challenge varies between and within languages. Yet, little is known about how neural processes react to these variable challenges beyond the planning of individual words. Here, we examine how fundamental differences in syntax shape the time course of sentence planning. Most languages treat alike (i.e., align with each other) the 2 uses of a word like “gardener” in “the gardener crouched” and in “the gardener planted trees.” A minority keeps these formally distinct by adding special marking in 1 case, and some languages display both aligned and nonaligned expressions. Exploiting such a contrast in Hindi, we used electroencephalography (EEG) and eye tracking to suggest that this difference is associated with distinct patterns of neural processing and gaze behavior during early planning stages, preceding phonological word form preparation. Planning sentences with aligned expressions induces larger synchronization in the theta frequency band, suggesting higher working memory engagement, and more visual attention to agents than planning nonaligned sentences, suggesting delayed commitment to the relational details of the event. Furthermore, plain, unmarked expressions are associated with larger desynchronization in the alpha band than expressions with special markers, suggesting more engagement in information processing to keep overlapping structures distinct during planning. Our findings contrast with the observation that the form of aligned expressions is simpler, and they suggest that the global preference for alignment is driven not by its neurophysiological effect on sentence planning but by other sources, possibly by aspects of production flexibility and fluency or by sentence comprehension. This challenges current theories on how production and comprehension may affect the evolution and distribution of syntactic variants in the world’s languages.

Little is known about the neural processes involved in planning to speak. This study uses eye-tracking and EEG to show that speakers prepare sentence structures in different ways and rely on alpha and theta oscillations differently when planning sentences with and without agent case marking, challenging theories on how production and comprehension affect language evolution.     

Word production errors in children with developmental language impairments

This review focuses on the errors that children with developmental language impairments make on three types of word production tasks: lexical retrieval, the elicitation of derivationally complex forms and the repetition of non-sense forms. The studies discussed in this review come principally from children with specific language impairment, and from children who are English-speakers or deaf users of British sign language. It is argued that models of word production need to be able to account for the data presented here, and need to have explanatory power across both modalities (i.e. speech and sign).     

White matter connectivity in children with autism spectrum disorders: a tract-based spatial statistics study

Background

Autism spectrum disorders (ASD) are associated with widespread alterations in white matter (WM) integrity. However, while a growing body of studies is shedding light on microstructural WM alterations in high-functioning adolescents and adults with ASD, literature is still lacking in information about whole brain structural connectivity in children and low-functioning patients with ASD. This research aims to investigate WM connectivity in ASD children with and without mental retardation compared to typically developing controls (TD).

Methods

Diffusion tensor imaging (DTI) was performed in 22 young children with ASD (mean age: 5.54 years) and 10 controls (mean age: 5.25 years). Data were analysed both using the tract-based spatial statistics (TBSS) and the tractography. Correlations were investigated between the WM microstructure in the identified altered regions and the productive language level.

Results

The TBSS analysis revealed widespread increase of fractional anisotropy (FA) in major WM pathways. The tractographic approach showed an increased fiber length and FA in the cingulum and in the corpus callosum and an increased mean diffusivity in the indirect segments of the right arcuate and the left cingulum. Mean diffusivity was also correlated with expressive language functioning in the left indirect segments of the arcuate fasciculus.

Conclusions

Our study confirmed the presence of several structural connectivity abnormalities in young ASD children. In particular, the TBSS profile of increased FA that characterized the ASD patients extends to children a finding previously detected in ASD toddlers only. The WM integrity abnormalities detected may be relevant to the pathophysiology of ASD, since the structures involved participate in some core atypical characteristics of the disorder.

     

不同碳水化合物对孤独症患儿肠道菌群 体外发酵产生短链脂肪酸的影响

目的探究孤独症谱系障碍(autism spectrum disorder,ASD)患儿与健康儿童的肠道菌群利用不同碳水化合物产生短链脂肪酸(short-chain fatty acids,SCFAs)的差异。方法前瞻性病例对照研究。选择2016年12月至2017年10月解放军总医院儿科门诊的15例ASD患儿为研究对象,并匹配15名健康儿童为对照组;收集研究对象粪便,稀释成10%悬浊液,然后分别接种到以乳果糖(LAU)、乳糖(LAT)、棉籽糖(RAF)、低聚半乳糖(GOS)、低聚异麦芽糖(IMO)和低聚甘露糖(MOS)为单碳源的肠道微生态小型模拟发酵系统中批量发酵24 h,检测SCFAs浓度、底物降解率和产气气压。结果 ASD组患儿粪便SCFAs浓度与对照组差异无统计学意义,在YCFA(无碳源对照培养基,蛋白发酵为主)培养基发酵后总SCFAs、乙酸和丙酸均低于对照组,差异有统计学意义(Z=-2.509、-2.509、-3.007,P=0.011、0.011、0.002);在添加LAT、RAF、GOS、IMO和MOS的培养基发酵后总SCFAs浓度显著高于对照组,差异有统计学意义(Z=2.385、2.344、2.675、2.344、2.302,P=0.016、0.019、0.007、0.019、0.021),而含LAU的培养基发酵后,两组研究对象总SCFAs浓度比较差异无统计学意义。结论 ASD患儿肠道菌群利用蛋白发酵产SCFAs能力显著低于健康对照,利用碳水化合物产SCFAs能力显著高于健康对照。6种发酵底物中,乳果糖是最适合ASD患儿的碳水化合物,有改善ASD患儿肠道菌群产SCFAs的潜力。     

Production and perception rules underlying visual patterns: effects of symmetry and hierarchy

Formal language theory has been extended to two-dimensional patterns, but little is known about two-dimensional pattern perception. We first examined spontaneous two-dimensional visual pattern production by humans, gathered using a novel touch screen approach. Both spontaneous creative production and subsequent aesthetic ratings show that humans prefer ordered, symmetrical patterns over random patterns. We then further explored pattern-parsing abilities in different human groups, and compared them with pigeons. We generated visual plane patterns based on rules varying in complexity. All human groups tested, including children and individuals diagnosed with autism spectrum disorder (ASD), were able to detect violations of all production rules tested. Our ASD participants detected pattern violations with the same speed and accuracy as matched controls. Children's ability to detect violations of a relatively complex rotational rule correlated with age, whereas their ability to detect violations of a simple translational rule did not. By contrast, even with extensive training, pigeons were unable to detect orientation-based structural violations, suggesting that, unlike humans, they did not learn the underlying structural rules. Visual two-dimensional patterns offer a promising new formally-grounded way to investigate pattern production and perception in general, widely applicable across species and age groups.     

Diurnal Rhythms in Performance Tests of School Children with and Without Language Disorders

Time-of-day related changes on four tests used by speech therapists and four other performance tests, in addition to oral temperature, were documented in 16 school children (7-9 years of age). Six of them had language disorders and were receiving speech therapy. Children were synchronized with diurnal activity from around 0730 to around 2100 and nocturnal rest. For each child, at each test time point (e.g. 0900, 1100, 1530 and 1930) tests were performed three times, with two different speech therapists, in a random order, with only one session per day. Conventional methods (r-tested mean differences; AINOVA; correlation tests) were used for statistical analyses. Among 29 parameters (items) which were analyzed, only nine exhibited time-of-day related changes, mainly in speed to-perform measures. In most detected rhythms best performance occurred either at 1100 or at 1530 with no difference in subgroups except for the fastest performance of the sentence repetition test. With regard to the daily mean M, controls performed better than children with language disorders for the word (syllabic) repetition test (P < 0.0004) but this was reversed for both computing and colouring skill tests (P < 0.04 and < 0.002). A difference related to sex (but not to language disorders) was observed in the Ms of speed in sign reproduction (P < 0.0000) and sorting cards (P < 0.01), with boys being faster than girls. In children, as in adults, time-of-day effects should be considered when the quantification of performance is desired.     

Lexical learning and lexical processing in children with developmental language impairments

Lexical skills are a crucial component of language comprehension and production. This paper reviews evidence for lexical-level deficits in children and young people with developmental language impairment (LI). Across a range of tasks, LI is associated with reduced vocabulary knowledge in terms of both breadth and depth and difficulty with learning and retaining new words; evidence is emerging from on-line tasks to suggest that low levels of language skill are associated with differences in lexical competition in spoken word recognition. The role of lexical deficits in understanding the nature of LI is also discussed.     

Impaired neurite development associated with mitochondrial dysfunction in dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of children with autism spectrum disorder

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by impaired social interactions, restrictive interests, and repetitive stereotypic behaviors. Among the various mechanisms underlying the pathogenesis of ASD, dysfunctions of dopaminergic signaling and mitochondria have been hypothesized to explain the core symptoms of children with ASD. However, only a few studies focusing on the pathological association between dopaminergic neurons (DN) and mitochondria in ASD have been performed using patient-derived stem cells and in vitro differentiated neurons. Stem cells from human exfoliated deciduous teeth (SHED) are neural crest-derived mesenchymal stem cells present in the dental pulp of exfoliated deciduous teeth; these cells can differentiate into dopaminergic neurons (DN) in vitro. This study aimed to investigate the pathological association between development of DN and mitochondria in ASD by using SHED as a disease- or patient-specific cellular model. The SHED obtained from three children with ASD and three typically developing children were differentiated into DN, and the neurobiology of these cells was examined. The DN derived from children with ASD showed impaired neurite outgrowth and branching, associated with decreased mitochondrial membrane potential, ATP production, number of mitochondria within the neurites, amount of mitochondria per cell area and intracellular calcium level. In addition, impaired neurite outgrowth and branching of ASD-derived DN were not improved by brain-derived neurotrophic factor (BDNF), suggesting impairment of the BDNF signaling pathway in ASD. These results imply that intracerebral dopamine production may have decreased in these children. The earliest age at which deciduous teeth spontaneously exfoliate in humans, and SHED can be noninvasively collected, is approximately 6 years. Our results suggest that in vitro analysis of SHED-derived DN obtained from children with ASD provides neurobiological information that may be useful in determining treatment strategies in the early stages of ASD.