Vocalization Rate and Consonant Production in Toddlers at High and Low Risk for Autism

Phonological Development in 3-6-Year-Old Mandarin-Speaking Children with Autism, Developmental Delays, and Typical Development

Research on the phonological development of children with autism spectrum disorder (ASD) has not yet reached consistent conclusions, and systematic studies from different language groups are needed. This study aimed to systematically investigate the characteristics of phonological development in 3-6 year-old Mandarin-speaking children with ASD. We analyzed 10 min speech samples from 21 children with ASD, 18 development level-matched children with developmental disorders (DD), and 15 chronological age-matched typically developing (TD) children during semi-structured parent-child free play based on Mandarin phonological features. The children with ASD had a significantly smaller inventory than those with TD on the initial and final inventories. The children with ASD had only a significantly smaller initial inventory than those with DD in Phases 2 and 4. Compared with TD children, children with ASD used a higher proportion of V1 and V1V2C and a smaller proportion of V1V2V3, CV1C, and CV1V2C. No significant differences existed between ASD and DD children in the proportion of any syllable structure, but V1V2V3, CV1, and CV1V2C numbers were significantly fewer than in DD children. Children with ASD were significantly greater than children with TD in the diversity of V1V2, CV1, and overall syllables. ASD children had significantly fewer different types of syllables in both V1V2C and CV1 than did DD children and significantly greater diversity in CV1 and overall syllables than did DD children. These preliminary data suggest that the gap between TD and ASD children's language abilities increased with age, and this gap was reflected in initial, final, and syllable complexity and diversity. Children with DD and ASD showed similar language abilities, and children with DD showed detailed differences from those with ASD regarding initial, syllable complexity and diversity.

Foundations of Vocal Category Development in Autistic Infants

The present study compared the infant's tendency in the first year of life to produce clusters of particular vocal types (squeals, vocants, and growls) in typically developing (TD) and autistic infants. Vocal clustering provides evidence of vocal category formation and may establish a foundation for speech development. Specifically, we compared the extent of vocal clustering across outcome groups and age groups. We also examined the associations between the extent of vocal clustering and later outcomes at 2 years within the autistic group. Randomly selected 5-min segments (27,153 5-min segments total) from 1293 all-day home recordings from 103 TD infants and 44 autistic infants across the first year were humancoded (about 9.75 h of data coded per infant on average) to derive vocal clustering patterns. Fisher's exact tests were used to compare the occurrence of squeals versus vocants, as well as growls versus vocants, across coded segments. Infants in both groups demonstrated clear clustering patterns of squeals and growls across all age groups. The extent of vocal clustering in the autistic group did not correlate significantly with later language, repetitive behavior, or autism severity outcomes. These findings highlight the robustness of the systematic production of vocal categories across the first year of life. The similarity of the clustering patterns in the TD and autistic groups suggests that vocal category formation through active infant vocal exploration is a robust feature of early speech development.

The first six months of life: A systematic review of early markers associated with later autism

There is now good evidence that behavioural signs of autism spectrum conditions (autism) emerge over the first two years of life. Identifying clear developmental differences early in life may facilitate earlier identification and intervention that can promote longer-term quality of life. Here we present a systematic review of studies investigating behavioural markers of later autism diagnosis or symptomology taken at 0-6 months. The following databases were searched for articles published between 01/01/2000 and 15/03/2022: Embase, Medline, Scopus, PubMed, PsycINFO, CINAHL, Web of Science and Proquest. Twenty-five studies met inclusion criteria: assessment of behaviour at 0-6 months and later assessment of autism symptomology or diagnosis. Studies examined behaviours of attention, early social and communication behaviours, and motor behaviours, as well as composite measures. Findings indicated some evidence of measures of general attention, attention to social stimuli, and motor behaviours associated with later autism diagnosis or symptomology. Findings were inconsistent regarding social and communication behaviours, with a lack of repeated or validated measures limiting drawing firm conclusions. We discuss implications of the findings and suggest recommendations for future research.

Oromotor skills in autism spectrum disorder: A scoping review

Oromotor functioning plays a foundational role in spoken communication and feeding, two areas of significant difficulty for many autistic individuals. However, despite years of research and established differences in gross and fine motor skills in this population, there is currently no clear consensus regarding the presence or nature of oral motor control deficits in autistic individuals. In this scoping review, we summarize research published between 1994 and 2022 to answer the following research questions: (1) What methods have been used to investigate oromotor functioning in autistic individuals? (2) Which oromotor behaviors have been investigated in this population? and (3) What conclusions can be drawn regarding oromotor skills in this population? Seven online databases were searched resulting in 107 studies meeting our inclusion criteria. Included studies varied widely in sample characteristics, behaviors analyzed, and research methodology. The large majority (81%) of included studies report a significant oromotor abnormality related to speech production, nonspeech oromotor skills, or feeding within a sample of autistic individuals based on age norms or in comparison to a control group. We examine these findings to identify trends, address methodological aspects hindering cross-study synthesis and generalization, and provide suggestions for future research.

Describing (pre)linguistic oral productions in 3- to 5-year-old autistic children: A cluster analysis

LAY ABSTRACT

For most autistic children, spoken language emergence and development happen after the age of 3. Once they start developing and using spoken language, some eventually manage to reach typical levels of language abilities, while others remain minimally speaking into adulthood. It is therefore difficult to consider young autistic preschoolers as a homogeneous group in terms of spoken language levels. In our study, we breakdown a representative and inclusive group of children on the spectrum aged from 3 to 5 into five subgroups that correspond to different linguistic profiles. To do so, we qualitatively described children's (pre)verbal productions elicited during interactions with a parent and with an experimenter. We then used a type of statistical analysis called cluster analysis to group together the children that had a similar expressive (pre)linguistic behavior. Using this analysis, we were able to delineate five linguistic profiles with qualitatively different patterns of vocal production. Two of these profiles are composed of speaking children; the three others are composed of non- or minimally speaking children. Our findings show that traditional binary division of speaking versus nonspeaking autistic children is not precise enough to describe the heterogeneity of early spoken language in young autistic children. They also support the use of qualitative descriptions of vocal productions and speech to accurately document children's level of language, which could, in turn, help design very finely tailored language intervention specific to each child.

Infant vocalizing and phenotypic outcomes in autism: Evidence from the first 2 years

Infant vocalizations are early-emerging communicative markers shown to be atypical in autism spectrum disorder (ASD), but few longitudinal, prospective studies exist. In this study, 23,850 infant vocalizations from infants at low (LR)- and high (HR)-risk for ASD (HR-ASD = 23, female = 3; HR-Neg = 35, female = 13; LR = 32, female = 10; 80% White; collected from 2007 to 2017 near Philadelphia) were analyzed at 6, 12, and 24 months. At 12 months, HR-ASD infants produced fewer vocalizations than HR-Neg infants. From 6 to 24 months, HR-Neg infants demonstrated steeper vocalization growth compared to HR-ASD and LR infants. Finally, among HR infants, vocalizing at 12 months was associated with language, social phenotype, and diagnosis at age 2. Infant vocalizing is an objective behavioral marker that could facilitate earlier detection of ASD.

The Vocabulary of Infants with an Elevated Likelihood and Diagnosis of Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Infant Language Studies Using the CDI and MSEL

Diagnoses of autism spectrum disorder (ASD) are typically accompanied by atypical language development, which can be noticeable even before diagnosis. The siblings of children diagnosed with ASD are at elevated likelihood for ASD diagnosis and have been shown to have higher prevalence rates than the general population. In this paper, we systematically reviewed studies looking at the vocabulary size and development of infants with autism. One inclusion criterion was that infants were grouped either pre-diagnostically as elevated or typical likelihood or post-diagnostically as ASD or without ASD. This review focused on studies that tested infants up to 24 months of age and that assessed vocabulary either via the parent-completed MacArthur–Bates Communicative Developmental Inventory (CDI) or the clinician-administered Mullen Scales of Early Learning (MSEL). Our systematic search yielded 76 studies. A meta-analysis was performed on these studies that compared the vocabulary scores of EL and TL infants pre-diagnostically and the scores of ASD and non-ASD infants post-diagnostically. Both pre- and post-diagnostically, it was found that the EL and ASD infants had smaller vocabularies than their TL and non-ASD peers, respectively. The effect sizes across studies were heterogenous, prompting additional moderator analyses of age and sub-group analyses of the language measure used (CDI or MSEL) as potential moderators of the effect size. Age was found to be a moderator both in the pre- and post-diagnostical groups, however, language measure was not a moderator in either diagnostic group. Interpretations and future research directions are discussed based on these findings.

Towards-Person Vocalization Effect on Screening for Autism Spectrum Disorders in the Context of Frustration

The purpose of this study is to investigate the vocalization characteristics of infants with autism spectrum disorder (ASD) in the context of frustration. The duration and frequency of vocalization in 48 infants with ASD and 65 infants with typical development (TD) were followed up to 24 months later for subsequent diagnosis. The typical vocalizations of infants with ASD were retrospectively analyzed, such as speech-like vocalizations, nonspeech vocalizations, vocalizations towards the person and non-social vocalizations. The results showed that, compared with the TD group, vocalizations of infants with ASD during the still-face period had lower typical vocalizations and characteristics associated with social intention, and that these characteristics were closely related to the clinical symptoms of ASD, among which vocalizations towards the person accompanied by social intention had discriminative efficacy.

Speech Abilities in a Heterogeneous Group of Children With Autism

PURPOSE

This study aimed to provide detailed descriptive information about the speech of a heterogeneous cohort of children with autism spectrum disorder (ASD) and to explore whether subgroups exist based on this detailed speech data. High rates of delayed and disordered speech in both low-verbal and high-functioning children with ASD have been reported. There is limited information regarding the speech abilities of young children across a range of functional levels.

METHOD

Participants were 23 children aged 2;0-6;11 (years;months) with a diagnosis of ASD. Comprehensive speech and language assessments were administered. Independent and relational speech analyses were conducted from single-word naming tasks and spontaneous speech samples. Hierarchical clustering based on language, nonverbal communication, and spontaneous speech descriptive data was completed.

RESULTS

Independent and relational speech analyses are reported. These variables are used in the cluster analyses, which identified three distinct subgroups: (a) children with high language and high speech ability (n = 10), (b) children with low expressive language and low speech ability but higher receptive language and use of gestures (n = 3), and (c) children with low language and low speech development (n = 10).

CONCLUSIONS

This is the first study to provide detailed descriptive speech data of a heterogeneous cohort of children with ASD and use this information to statistically explore potential subgroups. Clustering suggests a small number of children present with low levels of speech and expressive language in the presence of better receptive language and gestures. This communication profile warrants further exploration. Replicating these findings with a larger cohort of children is needed. Supplemental Material https://doi.org/10.23641/asha.16906978.

Examining Useful Spoken Language in a Minimally Verbal Child With Autism Spectrum Disorder: A Descriptive Clinical Single-Case Study

Purpose This was a companion study to a previous one (Biller & Johnson, 2019). The purpose was to develop a detailed descriptive profile of a minimally verbal child with a unique medical history and autism spectrum disorder (ASD). The present report describes his social-cognitive and speech sound production abilities in relation to his potentially burgeoning spoken language. Method This in-depth, descriptive, clinical single-case study focused on a 3-year-old boy who was diagnosed with a chromosomal abnormality and ASD. The size of his spoken vocabulary fell at the upper limit for classifying a child as minimally verbal. His demographic information was obtained, in addition to general information from his mother. Four social-cognitive and three speech sound production abilities were assessed, as well as his overall performance in both domains. The study included a parent interview and two child assessment sessions. Results The child exhibited low social-cognitive and speech sound production abilities for his age, with social-cognitive abilities higher than speech sound production abilities. Comparison with the previous study revealed substantial gaps in social cognition and speech sound production between this child and five other minimally verbal children with ASD. His higher abilities in these two domains co-occurred with his larger spoken vocabulary size. Conclusions Although the child's social-cognitive abilities were low for his age, with his speech sound production abilities even lower, both domains were perhaps high enough to support spoken vocabulary at the upper limit for minimally verbal children. Indeed, there appeared to be quantitative and qualitative differences between him and other minimally verbal children in the previous study. The possibility was explored that there is a point or threshold along the developmental continua for social cognition and speech sound production that allows for expansion into useful language.

A Six-Minute Measure of Vocalizations in Toddlers with Autism Spectrum Disorder

To improve early identification of autism spectrum disorder (ASD), we need objective, reliable, and accessible measures. To that end, a previous study demonstrated that a tablet-based application (app) that assessed several autism risk behaviors distinguished between toddlers with ASD and non-ASD toddlers. Using vocal data collected during this study, we investigated whether vocalizations uttered during administration of this app can distinguish among toddlers aged 16-31 months with typical development (TD), language or developmental delay (DLD), and ASD. Participant's visual and vocal responses were recorded using the camera and microphone in a tablet while toddlers watched movies designed to elicit behaviors associated with risk for ASD. Vocalizations were then coded offline. Results showed that (a) children with ASD and DLD were less likely to produce words during app administration than TD participants; (b) the ratio of syllabic vocalizations to all vocalizations was higher among TD than ASD or DLD participants; and (c) the rates of nonsyllabic vocalizations were higher in the ASD group than in either the TD or DLD groups. Those producing more nonsyllabic vocalizations were 24 times more likely to be diagnosed with ASD. These results lend support to previous findings that early vocalizations might be useful in identifying risk for ASD in toddlers and demonstrate the feasibility of using a scalable tablet-based app for assessing vocalizations in the context of a routine pediatric visit. LAY SUMMARY: Although parents often report symptoms of autism spectrum disorder (ASD) in infancy, we are not yet reliably diagnosing ASD until much later in development. A previous study tested a tablet-based application (app) that recorded behaviors we know are associated with ASD to help identify children at risk for the disorder. Here we measured how children vocalize while they watched the movies presented on the tablet. Children with ASD were less likely to produce words, less likely to produce speechlike sounds, and more likely to produce atypical sounds while watching these movies. These measures, combined with other behaviors measured by the app, might help identify which children should be evaluated for ASD. Autism Res 2020, 13: 1373-1382. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Language Growth in Young Children with Autism: Interactions Between Language Production and Social Communication

Young children with autism spectrum disorder (ASD) present with a broad range of spoken language abilities, as well as delays in precursor skills such as gesture production and joint attention skills. While standardized assessments describe language strengths, the Communication and Symbolic Behavior Scales (CSBS-DP) is a particularly robust measure as it additionally characterizes precise aspects of social communication. This study provides a unique contribution by assessing the interactional effects of CSBS-DP Social Composite performance with early language samples on later language outcomes. Our results indicate that multiple social communication elements significantly interact with early spoken language to predict later language. Our findings also highlight the transactional relationship between early spoken vocabulary and social communication skills that bolster language development growth.

Does phonetic repertoire in minimally verbal autistic preschoolers predict the severity of later expressive language impairment?

Trajectories of expressive language development are highly heterogeneous in autism. Yoder et al. found that parental responsiveness, child response to joint attention, child communicative intent and consonant inventory were unique predictors of expressive language growth in minimally verbal preschoolers 16 months later ( n = 87). This study applied these predictors to an independent sample, over a 12-month period ( n = 27). A broader measure of phonetic repertoire, combining reported, elicited and observed speech sounds, was included to further understand the contribution of speech production skills. Expressive language growth was highly variable: 65% remained minimally verbal at mean age 5;2, while 7% gained over 340 words. Contrary to expectations, communicative intent, parent responsiveness and response to joint attention were not found to predict expressive language growth or outcome. In contrast, both consonant inventory and phonetic repertoire were significant predictors (adjusted R2 = 0.29 and 0.45). These results underscore the contribution of speech production abilities to expressive language development in this population, which may reflect an additional deficit rather than a consequence of core autism symptoms. Future work should include those with the most persistently limited expressive language, so that findings can be generalized and additional barriers to communication identified and addressed.

Lay abstract

What is already known about the topic? Language skills vary enormously in autism: while some autistic individuals can engage in sophisticated conversations, many remain minimally verbal, meaning they use few or no words regularly for communication. We do not know what causes this variation, but we do know that certain child and family characteristics can be measured when a child is young, and this information can improve our prediction of how expressive language might develop over time. What this article adds? We examined four characteristics, which have already been found to predict language development in young minimally verbal autistic children. We followed the expressive language progress of 27 minimally verbal children, aged three to five, for a year. One-third no longer met the minimally verbal criteria at the end of the study. In this sample, only one factor predicted language progress, which was the child’s initial speech skills (the number of different speech sounds that the child made during an interaction). This finding adds to the evidence that speech skills contribute to language development in autism. In some cases, persistent and severe expressive language difficulties may reflect an additional deficit in speech production, rather than a consequence of core autism features. Implications for practice, research or policy Our findings suggest that there are factors other than social skills that influence language development in autism. Careful assessment of speech production should be considered when language does not develop as expected. Future research should evaluate speech skills interventions for minimally verbal autistic individuals, as well as promoting the use of alternative communication systems.

Pre- and Paralinguistic Vocal Production in ASD: Birth Through School Age

PURPOSE OF REVIEW

We review what is known about how pre-linguistic vocal differences in autism spectrum disorder (ASD) unfold across development and consider whether vocalization features can serve as useful diagnostic indicators.

RECENT FINDINGS

Differences in the frequency and acoustic quality of several vocalization types (e.g., babbles and cries) during the first year of life are associated with later ASD diagnosis. Paralinguistic features (e.g., prosody) measured during early and middle childhood can accurately classify current ASD diagnosis using cross-validated machine learning approaches. Pre-linguistic vocalization differences in infants are promising behavioral markers of later ASD diagnosis. In older children, paralinguistic features hold promise as diagnostic indicators as well as clinical targets. Future research efforts should focus on (1) bridging the gap between basic research and practical implementations of early vocalization-based risk assessment tools, and (2) demonstrating the clinical impact of targeting atypical vocalization features during social skill interventions for older children.

Failure to attune to language predicts autism in high risk infants

Young humans are typically sensitive to evolutionarily important aspects of information in the surrounding environment in a way that makes us thrive. Seeking to probe the putative disruptions of this process in infancy, I examined the statistical character of head movements in 52 9-10 mo-old infants, half at high familial risk (HR) for Autism Spectrum Disorders (ASD), who underwent an fMRI scan while listening to words spoken with alternating stress patterns on syllables. Relative to low risk (LR) infants, HR infants, in particular those showing the least rapid receptive language progress, had significantly lower noise-to-signal levels and increased symmetry. A comparison of patterns during a native language and a sleep scan revealed the most atypical ordering of signatures on the 3 tasks in a subset of HR infants, suggesting that the biological mechanism of language development is least acquisitive in those HR infants who go on to develop ASD in toddlerhood.

Social-Cognitive and Speech Sound Production Abilities of Minimally Verbal Children With Autism Spectrum Disorders

Purpose To date, there has been a dearth of systematic research that examines both social-cognitive (SC) and speech sound production (SSP) abilities simultaneously in minimally verbal (MV) children with autism spectrum disorders (ASDs). Such an analysis would allow a unified and comprehensive view of the children's communication abilities. The purpose of this study was to develop detailed descriptive profiles of MV children with ASD and uncover patterns in their SC and SSP abilities that may pertain to spoken language. Method This study was a descriptive, multiple clinical case study that examined 5 MV children with ASD, 4 boys and 1 girl, aged 3-6 years. The case studies consisted of demographic information, parent report, and formal and informal assessment of the children. Four SC abilities and 3 SSP abilities were assessed. Results The 5 children's SC score, SSP score, and number of spoken words were converted to z scores. This analysis revealed 2 different patterns of development: 3 of the children had lower SC than SSP abilities, and 2 of the children had the reverse pattern. Conclusions The 5 children were low in both SC and SSP abilities. Although both domains were low, the measure that coincided most with spoken vocabulary among the 5 children was their SSP abilities. Specifically, the children had difficulty in demonstrating emerging control of the onset of voicing for specific speech sounds and verbal imitation of single speech sounds and syllables. Clinical implications of simultaneously assessing and treating SC and SSP abilities in MV children are discussed.

Regression in autism spectrum disorder: Reconciling findings from retrospective and prospective research

The way in which the behavioral manifestations of autism spectrum disorder (ASD) emerge in infancy is variable. Regression-loss of previously acquired skills-occurs in a subset of children. However, the etiology and significance of regression remains unclear. Until recently, investigation of regression relied on retrospective report by parents or examination of home videos from early in life. However, home videos and retrospective report of the nature and timing of regression, and association with factors such as illness or immunization, is potentially subject to bias. The advent of prospective studies of infant siblings at familial high-risk of ASD has the potential to document regression as it occurs. Recent research has suggested that subtle loss of skills occurs in a larger proportion of children with ASD than previously assumed; however, there are few reports of clear-cut regressions, such as that involving dramatic loss of language and other established skills, in the prospective literature. This could be because of the following: clear-cut regression occurs less commonly than parent report suggests, study design limits the potential to detect regression, or there are differences between multiplex and simplex families in the rate of de novo genetic mutations and therefore regression risk. This review will bring together literature from retrospective and prospective research and attempt to reconcile diverging findings, with a specific focus on methodological issues. Changing conceptualizations of regression will be discussed, as well as etiological factors that may be associated with regression. The main challenges that need to be addressed to measure regression in prospective studies will be set out. Autism Research 2018, 11: 1602-1620. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Regression-a loss of previously established skills-occurs in a subset of children with ASD. Parental recall is not always accurate but studying younger siblings of children with ASD, 10-20% of whom will develop ASD, should make it possible to measure regression as it occurs. Clear-cut regression, like loss of language, has not often been reported in infant sibling studies, but recent research suggests that gradual loss of social engagement might be more common. This review looks at the evidence for regression from infant sibling studies and asks how study design affects the likelihood of capturing regression.