Evidence against poor semantic encoding in individuals with autism

Lexical Semantic Knowledge of Children with ASD—a Review Study

Studies on the lexical semantic abilities of children with autism have yielded contradicting results. The aim of the current review was to explore studies that have specifically focused on the lexical semantic abilities of children with ASD and try to find an explanation for these contradictions. In the 32 studies reviewed, no single factor was found to affect lexical semantic skills, although children with broader linguistic impairment generally, but not universally, also showed impaired lexical semantic skills. The need for future studies with young ASD participants, with differing intellectual functioning, longitudinal studies, and studies assessing a wide range of language domains are discussed.

The Episodic Memory Profile in Autism Spectrum Disorder: A Bayesian Meta-Analysis

Although autism spectrum disorders (ASD) are commonly characterized by diminished episodic memory, the literature in this area is mixed. We address these inconsistent findings by employing multilevel Bayesian meta-analysis to quantify episodic memory differences between individuals with ASD and typically developing (TD) controls. We used meta-regression to evaluate the effects of test modality (e.g., word list, story recall), delay interval (immediate vs. delayed), retrieval demands (recognition vs. recall), and sensory modality (auditory vs. visual) on episodic memory in ASD. A total of 338 effect sizes from 113 empirical articles, including 5,632 unique participants (ASD = 2,777, TD = 2,855), were included. Results show that the memory deficits associated with ASD were larger for recall (g = -0.52, se = 0.04, 95% CrI [-0.60, -0.43]) compared to recognition (g = -0.25, se = 0.05, 95% CrI [-0.35, -0.14]) and differed based on the testing modality. For example, effect sizes were smallest for words (g = -0.28, se = 0.05, 95% CrI [-0.38, -0.18]), pictures (g = -0.38, se = 0.07, 95% CrI [-0.52, -0.24]), and figure reproduction (g = -0.49, se = 0.11, 95% CrI [-0.70, -0.27]). However, effect sizes for sentences (g = -0.59, se = 0.20, 95% CrI [-1.00, -0.21]), stories (Hedges' g = -0.54, se = 0.08, 95% CrI [-0.69, -0.38]) and staged events (g = -0.75, se = 0.10, 95% CrI [-0.95, -0.55]) were much larger. These findings suggest that ASD is associated with a small to medium reduction in scores on episodic memory tests relative to TD controls.

Retrieval practice improves memory in patients with schizophrenia: new perspectives for cognitive remediation

BACKGROUND

Schizophrenia is associated with severe cognitive deficits, particularly episodic memory deficits, that interfere with patients' socio-professional functioning. Retrieval practice (also known as testing effect) is a well-established episodic memory strategy that involves taking an initial memory test on a previously learned material. Testing later produces robust long-term memory improvements in comparison to the restudy of the same material both in healthy subjects and in some clinical populations with memory deficits. While retrieval practice might represent a relevant cognitive remediation strategy in patients with schizophrenia, studies using optimal procedures to explore the benefits of retrieval practice in this population are still lacking. Therefore, the purpose of our study was to investigate the benefits of retrieval practice in patients with schizophrenia.

METHODS

Nineteen stabilised outpatients with schizophrenia (DSM-5 criteria) and 20 healthy controls first studied a list of 60 word-pairs (30 pairs with weak semantic association and 30 non associated pairs). Half the pairs were studied again (restudy condition), while only the first word of the pair was presented and the subject had to recall the second word for the other half (retrieval practice condition). The final memory test consisted in a cued-recall which took place 2 days later. Statistical analyses were performed using Bayesian methods.

RESULTS

Cognitive performances were globally altered in patients. However, in both groups, memory performances for word-pairs were significantly better after retrieval practice than after restudy (56.1% vs 35.7%, respectively, Pr(RP > RS) > 0.999), and when a weak semantic association was present (64.7% vs 27.1%, respectively; Pr(weak > no) > 0.999). Moreover, the positive effect of RP was observed in all patients but one.

CONCLUSIONS

Our study is the first to demonstrate that retrieval practice efficiently improves episodic memory in comparison to restudy in patients with schizophrenia. This learning strategy should therefore be considered as a useful tool for cognitive remediation programs. In this perspective, future studies might explore retrieval practice using more ecological material.

Exploring the neurocognitive basis of episodic recollection in autism

Increasing evidence indicates that the subjective experience of recollection is diminished in autism spectrum disorder (ASD) compared to neurotypical individuals. The neurocognitive basis of this difference in how past events are re-experienced has been debated and various theoretical accounts have been proposed to date. Although each existing theory may capture particular features of memory in ASD, recent research questions whether any of these explanations are alone sufficient or indeed fully supported. This review first briefly considers the cognitive neuroscience of how episodic recollection operates in the neurotypical population, informing predictions about the encoding and retrieval mechanisms that might function atypically in ASD. We then review existing research on recollection in ASD, which has often not distinguished between different theoretical explanations. Recent evidence suggests a distinct difficulty engaging recollective retrieval processes, specifically the ability to consciously reconstruct and monitor a past experience, which is likely underpinned by altered functional interactions between neurocognitive systems rather than brain region-specific or process-specific dysfunction. This integrative approach serves to highlight how memory research in ASD may enhance our understanding of memory processes and networks in the typical brain. We make suggestions for future research that are important for further specifying the neurocognitive basis of episodic recollection in ASD and linking such difficulties to social developmental and educational outcomes.

Semantic richness and word learning in children with autism spectrum disorder

Semantically rich learning contexts facilitate semantic, phonological, and articulatory aspects of word learning in children with typical development (TD). However, because children with autism spectrum disorder (ASD) show differences at each of these processing levels, it is unclear whether they will benefit from semantic cues in the same manner as their typical peers. The goal of this study was to track how the inclusion of rich, sparse, or no semantic cues influences semantic, phonological, and articulatory aspects of word learning in children with ASD and TD over time. Twenty-four school-aged children (12 in each group), matched on expressive vocabulary, participated in an extended word learning paradigm. Performance on five measures of learning (referent identification, confrontation naming, defining, phonetic accuracy, and speech motor stability) were tracked across three sessions approximately one week apart to assess the influence of semantic richness on extended learning. Results indicate that children with ASD benefit from semantically rich learning contexts similarly to their peers with TD; however, one key difference between the two groups emerged - the children with ASD showed heightened shifts in speech motor stability. These findings offer insights into common learning mechanisms in children with ASD and TD, as well as pointing to a potentially distinct speech motor learning trajectory in children with ASD, providing a window into the emergence of stereotypic vocalizations in these children.

Language and traits of autism spectrum conditions: evidence of limited phenotypic and etiological overlap

Language difficulties have historically been viewed as integral to autism spectrum conditions (ASC), leading molecular genetic studies to consider whether ASC and language difficulties have overlapping genetic bases. The extent of genetic, and also environmental, overlap between ASC and language is, however, unclear. We hence conducted a twin study of the concurrent association between autistic traits and receptive language abilities. Internet-based language tests were completed by ~3,000 pairs of twins, while autistic traits were assessed via parent ratings. Twin model fitting explored the association between these measures in the full sample, while DeFries-Fulker analysis tested these associations at the extremes of the sample. Phenotypic associations between language ability and autistic traits were modest and negative. The degree of genetic overlap was also negative, indicating that genetic influences on autistic traits lowered language scores in the full sample (mean genetic correlation = -0.13). Genetic overlap was also low at the extremes of the sample (mean genetic correlation = 0.14), indicating that genetic influences on quantitatively defined language difficulties were largely distinct from those on extreme autistic traits. Variation in language ability and autistic traits were also associated with largely different nonshared environmental influences. Language and autistic traits are influenced by largely distinct etiological factors. This has implications for molecular genetic studies of ASC and understanding the etiology of ASC. Additionally, these findings lend support to forthcoming DSM-5 changes to ASC diagnostic criteria that will see language difficulties separated from the core ASC communication symptoms, and instead listed as a clinical specifier.

Considerando a responsividade: uma proposta de análise pragmática no espectro do autismo

OBJETIVO: Comparar o perfil pragmático das iniciativas de comunicação e o perfil bidimensional envolvendo os aspectos de iniciativa e responsividade. Além disso, buscou-se analisar os tipos mais comuns de resposta apresentadas pelos indivíduos pesquisados. MÉTODOS: Foram analisadas trinta gravações de terapia fonoaudiológica, nas quais as terapeutas interagiam com crianças do espectro do autismo (média de idade: 9 anos e 6 meses). As filmagens foram transcritas e os dados derivados foram analisados quanto ao número de atos comunicativos, à ocupação do espaço comunicativo e ao uso dos meios verbal, vocal e gestual nas iniciativas e no total de participações (iniciativas e respostas). As respostas apresentadas foram qualificadas como: não resposta, resposta adequada, resposta inadequada e resposta pragmaticamente inapropriada. RESULTADOS: Houve diferença na comparação entre as iniciativas e o total de participações no que concerne à ocupação do espaço comunicativo e no total de atos. Quanto às respostas, houve diferença no número de respostas adequadas. CONCLUSÃO: Os resultados evidenciaram a necessidade de considerar o perfil bidimensional de comunicação e ressaltaram a necessidade de qualificar as respostas a fim de discriminar as habilidades comunicativas da criança.

Research review: structural language in autistic spectrum disorder - characteristics and causes

BACKGROUND

Structural language anomalies or impairments in autistic spectrum disorder (ASD) are theoretically and practically important, although underrecognised as such. This review aims to highlight the ubiquitousness of structural language anomalies and impairments in ASD, and to stimulate investigation of their immediate causes and implications for intervention.

METHOD

Studies of structural language in ASD are reviewed (based on a search of the literature and selected as meeting defined inclusion criteria), and explanatory hypotheses are discussed.

RESULTS

Some individuals with ASD never acquire language. Amongst those who do, language abilities range from clinically normal (ALN) to various degrees of impairment (ALI). Developmental trajectories and individual profiles are diverse, and minority subgroups have been identified. Specifically: language is commonly but not always delayed and delayed early language is always characterised by impaired comprehension and odd utterances, and sometimes by deviant articulation and grammar. Nevertheless, by school age an 'ASD-typical' language profile emerges from group studies, with articulation and syntax least affected, and comprehension, semantics and certain facets of morphology most affected. Thus, even individuals with ALN have poor comprehension relative to expressive language; also semantic-processing anomalies and idiosyncratic word usage. It is argued that impaired socio-emotional-communicative relating, atypical sensory-perceptual processing, and uneven memory/learning abilities may underlie shared language anomalies across the spectrum; and that varying combinations of low nonverbal intelligence, semantic memory impairment and comorbidities including specific language impairment (SLI), hearing impairment, and certain medical syndromes underlie ALI and variation in individual profiles.

CONCLUSIONS

Structural language is universally affected in ASD, due to a complex of shared and unshared causal factors. There is an urgent need for more research especially into the characteristics and causes of clinically significant language impairments.

Perfil funcional de comunicação e desempenho sócio-cognitivo de adolescentes autistas institucionalizados

OBJETIVO: o objetivo dessa pesquisa foi descrever as características funcionais da comunicação de adolescentes autistas institucionalizados, ao longo de um período de aproximadamente seis meses, nos aspectos de: número de atos comunicativos por minuto, proporção de interpessoalidade da comunicação e proporção de utilização dos meios comunicativos gestual, vocal e verbal assim como descrever as características do desempenho sócio-cognitivo dos sujeitos ao longo desse período. MÉTODOS: foram sujeitos dessa pesquisa oito adolescentes autistas institucionalizados que foram avaliados durante seis meses quanto ao perfil funcional de comunicação e ao desempenho sócio-cognitivo. Os dados obtidos foram submetidos à análise estatística não paramétrica. RESULTADOS: foi observada evolução quanto ao número de atos comunicativos por minuto e à proporção de funções comunicativas interpessoais, mas não foi observada evolução significativa quanto aos aspectos sócio-cognitivos. CONCLUSÃO: foi possível observar evolução na linguagem em adolescentes autistas institucionalizados num período de tempo de seis meses, mas não foi possível identificar correlações com o desempenho sócio-cognitivo.

A review of recent reports on autism: 1000 studies published in 2007

From 1000 studies published in 2007 on all aspects of autism, those that reached clear conclusions or included quantitative data were selected for this review. Possible etiologies include elemental metals, especially the inconsistent evidence regarding mercury from the vaccine preservative thimerosal, not used after 2001, and chromosomes and genes with the conclusion that autism has a complex genetic architecture. Also, various parental conditions are considered, as are many different abnormalities in the central nervous system, especially underconnectivity within the cortex. Furthermore, deficiencies in mirror neurons have been proposed, leading to the "theory of mind" explanation that autistic children tend to disregard others. In addition, various global deficiencies, like an increase in inhibitory synaptic transmission, are proposed. Characteristics of these children include selective (inward) attention; underresponsiveness; stereotyped repetitive motor behavior; increased head size, weight, and height; various cognitive and communicative disorders; and also epilepsy. Therapy has emphasized risperidone, but some atypical antipsychotic medications have been helpful, as have robotic aids, massage, hyperbaric oxygen, and music. Nearly every conceivable problem that a child could have can be observed in these unfortunate children.