Vocal patterns in infants with autism spectrum disorder: canonical babbling status and vocalization frequency

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.

Socioeconomic Deprivation Detrimentally Influences Language Outcomes in Toddlers With Cleft Palate

PURPOSE

The purpose of this study was to examine the influence of socioeconomic deprivation on language and developmental outcomes in toddlers with cleft palate with or without cleft lip (CP ± L). Other factors known to influence language outcomes were also considered, including home language history, history of hearing problems, syndromic diagnoses, and sex.

METHOD

A multicenter, cross-sectional study design was conducted. Data for 566 16-month-old toddlers with CP ± L were collected from 17 outpatient cleft palate clinics located throughout the United States. Outcome measures included the MacArthur-Bates Communicative Development Inventories, LENA Developmental Snapshot, age at first word as reported by the caregiver, and the Ages and Stages Questionnaires-Third Edition (ASQ-3). Multivariable linear or logistic regression was used to determine the influence of socioeconomic deprivation, as measured by the Area Deprivation Index, on language and developmental outcomes.

RESULTS

Greater socioeconomic deprivation significantly predicted poorer language outcomes in toddlers with CP ± L, including receptive vocabulary words (p = .02), expressive vocabulary words (p = .02), and late-developing gestures (p = .02). Additionally, toddlers from less affluent neighborhoods produced their first words significantly later than their counterparts living in more affluent areas (p < .01). Lower maternal education levels predicted significantly increased risk for problem solving delays (p < .01), and patients with subsidized insurance were at significantly increased risk for personal-social delays on the ASQ-3 (p < .01).

CONCLUSIONS

Children with CP ± L are susceptible to developmental delays associated with socioeconomic deprivation. These findings have implications for identifying a child's individual risk factors for developmental language disorders when conducting speech-language assessments. Future study should examine how inequities in care can be mitigated and addressed.

Vocal and early speech development in Korean-acquiring children with hearing loss and typical hearing

This study investigated the vocal and early speech development of Korean-acquiring children with hearing loss (HL) who underwent early auditory amplification compared to their typical hearing (TH) counterparts. The research focused on phonological characteristics of child vocalisation based on samples collected from naturalistic home environments. One-day home recordings using a Language ENvironment Analysis (LENA) recorder were obtained from 6 children with HL and 12 children with TH who ranged from 17 to 23 months of age in Korean monolingual environments. Child volubility, canonical babbling ratio (CBR), consonant distributions, and utterance structures of vocalisations were evaluated through qualitative and quantitative analyses of vocalisation samples collected from LENA recordings. The findings revealed that children with HL displayed comparable vocalisation levels to children with TH, with no significant differences in volubility and CBR. In consonant and utterance shape inventories, noticeable quantitative and qualitative differences were observed between children with HL and those with TH. The study also suggested both universal and language-specific production patterns, revealing the early effects of ambient language on consonant distributions and utterance structures within their vocalisation repertoire. This study emphasised the role of auditory input and the importance of early auditory amplification to support speech development in children with HL.

Daylong egocentric recordings in small- and large-scale language communities: A practical introduction

Daylong egocentric (i.e., participant-centered) recordings promise an unprecedented view into the experiences that drive early language learning, impacting both assumptions and theories about how learning happens. Thanks to recent advances in technology, collecting long-form audio, photo, and video recordings with child-worn devices is cheaper and more convenient than ever. These recording methods can be similarly deployed across small- and large-scale language communities around the world, opening up enormous possibilities for comparative research on early language development. However, building new high-quality naturalistic corpora is a massive investment of time and money. In this chapter, we provide a practical look into considerations relevant for developing and managing daylong egocentric recording projects: Is it possible to re-use existing data? How much time will manual annotation take? Can automated tools sufficiently tackle the questions at hand? We conclude by outlining two exciting directions for future naturalistic child language research.

Canonical babbling trajectories across the first year of life in autism and typical development

LAY ABSTRACT

Our study examined how babies develop their ability to talk to help identify early signs of autism. We looked at babies' production of babbling with mature syllables across the first year of life. Babies usually start producing mature babbling at 7 months of age before they say their first words. Some studies have suggested that babies who are later diagnosed with autism produce this kind of babbling less frequently in their first year of life, but other studies have shown complicated outcomes. In this new study, we followed 44 autistic babies and compared them to 127 typically developing babies. We recorded the babies once every month, all day long, from the time that they were born until they were around 13 months old. Then, we studied their mature babbling from segments of these recordings. We found that the rate at which babies used mature babbling was lower in boys with autism, and higher in girls with autism, compared to babies without autism. This research helps us understand how babies with autism learn to talk. It also raises important questions about differences between boys and girls with autism. Our study can help us improve how scientists and clinicians can identify autism earlier, which could lead to better communication supports for autistic children and their families.

Babbling in extremely premature infants at 12 months corrected age

Babbling is an important precursor to speech in infancy, and deviations from the typical babbling development can predict later difficulties in speech, language, and communication. This cross-sectional study aimed to investigate babbling and early speech in Swedish extremely premature infants. Samples of babbling were collected from 20 extremely premature infants (EPT group) at the corrected age of 12 months. Data collection was home-based and consisted of an audio-video recording of each infant playing with a parent. Presence of canonical babbling (CB), and three oral stop variables distinctive of typical babbling, and consonant inventory were assessed. The assessment was performed during a standardised observation of babbling. Data from the EPT group were compared to previously collected data of a reference group of 20 10-month-old infants without known medical diagnoses. The results showed that the EPT group had a lower proportion of infants producing CB, and that they used a significantly smaller consonant inventory compared to the reference group. Although not statistically significant, oral stops were less frequently found in the EPT group. The findings of a restricted consonant inventory and low proportion of CB in the EPT group are not surprising considering that the group has been found to be at risk of speech and language delay in toddlerhood. Still, further research is needed to explore whether babbling at 12 months can predict speech and language skills at an older age in extremely premature infants.

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.

White matter development and language abilities during infancy in autism spectrum disorder

White matter (WM) fiber tract differences are present in autism spectrum disorder (ASD) and could be important markers of behavior. One of the earliest phenotypic differences in ASD are language atypicalities. Although language has been linked to WM in typical development, no work has evaluated this association in early ASD. Participants came from the Infant Brain Imaging Study and included 321 infant siblings of children with ASD at high likelihood (HL) for developing ASD; 70 HL infants were later diagnosed with ASD (HL-ASD), and 251 HL infants were not diagnosed with ASD (HL-Neg). A control sample of 140 low likelihood infants not diagnosed with ASD (LL-Neg) were also included. Infants contributed expressive language, receptive language, and diffusion tensor imaging data at 6-, 12-, and 24 months. Mixed effects regression models were conducted to evaluate associations between WM and language trajectories. Trajectories of microstructural changes in the right arcuate fasciculus were associated with expressive language development. HL-ASD infants demonstrated a different developmental pattern compared to the HL-Neg and LL-Neg groups, wherein the HL-ASD group exhibited a positive association between WM fractional anisotropy and language whereas HL-Neg and LL-Neg groups showed weak or no association. No other fiber tracts demonstrated significant associations with language. In conclusion, results indicated arcuate fasciculus WM is linked to language in early toddlerhood for autistic toddlers, with the strongest associations emerging around 24 months. To our knowledge, this is the first study to evaluate associations between language and WM development during the pre-symptomatic period in ASD.

The Stability and Validity of Automated Indices of Vocal Development in Infants With Autistic and Non-Autistic Siblings

PURPOSE

This study evaluates the extent to which automated indices of vocal development are stable and valid for predicting language in infants at increased familial likelihood for autism and/or language impairment and relatively lower likelihood infants.

METHOD

A group of infants with autistic siblings (Sibs-autism; 20 infants) and a comparison group of infants with non-autistic siblings (Sibs-NA; 20 infants) wore Language ENvironment Analysis (LENA) recording devices for 16 hr on 2 days within a 1-week period. Extant software was used to derive several putative indices of vocal development from these recordings. Stability of these variables was examined across and within groups. Expressive and receptive language aggregates were calculated for each participant. Multiple regression analyses were used to (a) evaluate zero-order correlations for variables derived from LENA recordings with concurrent and future language and (b) test whether those associations were moderated by group status.

RESULTS

Both stability and validity differed by variable and group status. All variables reached acceptable stability in the Sibs-autism group within two to three observations, whereas stability of most variables was attenuated in the Sibs-NA group. No variables were associated with concurrent language in the theoretically motivated direction across groups, but two variables were strongly associated with concurrent expressive language in only the Sibs-NA group. Additionally, two variables were associated with later expressive language, though these correlations were again stronger in the Sibs-NA versus Sibs-autism group.

CONCLUSIONS

Although selected automated indices of vocal development were stable in Sibs-autism and/or valid for predicting expressive language within Sibs-NA, no scores showed strong, theoretically motivated associations with language within the Sibs-autism group. Automated indices of vocal development may, thus, have limited validity or clinical utility for predicting language development in infants at elevated familial likelihood for autism.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24415735.

Update on Identification and Treatment of Infants and Toddlers With Suspected Childhood Apraxia of Speech

PURPOSE

The purpose of this tutorial is to (a) provide an updated review of the literature pertaining to proposed early features of childhood apraxia of speech (CAS), (b) discuss the findings of recent treatment studies of infants and toddlers with suspected CAS (sCAS), and (c) present evidence-based strategies and tools that can be used for the identification of and intervention for infants and toddlers with sCAS or at high risk for the disorder.

METHOD

Since Davis and Velleman's (2000) seminal work on assessment and intervention in infants and toddlers with sCAS, limited research has guided clinicians in the complex task of identifying and treating early speech motor difficulties prior to a definitive diagnosis of CAS. Following the structure of Davis and Velleman, we explore the proposed early characteristics of CAS with reference to contemporary research. Next, we describe the limited treatment studies that have investigated intervention for infants and toddlers at risk of or suspected of having CAS. Finally, we present practical suggestions for integrating this knowledge into clinical practice.

CONCLUSIONS

Many of the originally proposed correlates of CAS in infants and toddlers now have research supporting their presence. However, questions remain about the developmental trajectory of the disorder. Although limited in number and restricted by lack of experimental control, emerging treatment studies can help guide clinicians in providing appropriate intervention to infants and toddlers with sCAS who need not wait for a definitive diagnosis to initiate intervention.

Sex differences in infant vocalization and the origin of language

Seeking to discern the earliest sex differences in language-related activities, our focus is vocal activity in the first two years of life, following up on recent research that unexpectedly showed boys produced significantly more speech-like vocalizations (protophones) than girls during the first year of life.We now bring a much larger body of data to bear on the comparison of early sex differences in vocalization, data based on automated analysis of all-day recordings of infants in their homes. The new evidence, like that of the prior study, also suggests boys produce more protophones than girls in the first year and offers additional basis for informed speculation about biological reasons for these differences. More broadly, the work offers a basis for informed speculations about foundations of language that we propose to have evolved in our distant hominin ancestors, foundations also required in early vocal development of modern human infants.

Understanding speech and language in tuberous sclerosis complex

Tuberous Sclerosis Complex (TSC), is a neurocutaneous disorder, associated with a high prevalence of autism spectrum disorder (ASD; ∼50% of individuals). As TSC is a leading cause of syndromic ASD, understanding language development in this population would not only be important for individuals with TSC but may also have implications for those with other causes of syndromic and idiopathic ASD. In this mini review, we consider what is known about language development in this population and how speech and language in TSC are related to ASD. Although up to 70% of individuals with TSC report language difficulties, much of the limited research to date on language in TSC has been based on summary scores from standardized assessments. Missing is a detailed understanding of the mechanisms driving speech and language in TSC and how they relate to ASD. Here, we review recent work suggesting that canonical babbling and volubility-two precursors of language development that predict the emergence of speech and are delayed in infants with idiopathic ASD-are also delayed in infants with TSC. We then look to the broader literature on language development to identify other early precursors of language development that tend to be delayed in children with autism as a guide for future research on speech and language in TSC. We argue that vocal turn-taking, shared attention, and fast mapping are three such skills that can provide important information about how speech and language develop in TSC and where potential delays come from. The overall goal of this line of research is to not only illuminate the trajectory of language in TSC with and without ASD, but to ultimately find strategies for earlier recognition and treatment of the pervasive language difficulties in this population.

The Utility of Natural Language Samples for Assessing Communication and Language in Infants Referred with Early Signs of Autism

Natural Language Sampling (NLS) offers clear potential for communication and language assessment, where other data might be difficult to interpret. We leveraged existing primary data for 18-month-olds showing early signs of autism, to examine the reliability and concurrent construct validity of NLS-derived measures coded from video-of child language, parent linguistic input, and dyadic balance of communicative interaction-against standardised assessment scores. Using Systematic Analysis of Language Transcripts (SALT) software and coding conventions, masked coders achieved good-to-excellent inter-rater agreement across all measures. Associations across concurrent measures of analogous constructs suggested strong validity of NLS applied to 6-min video clips. NLS offers benefits of feasibility and adaptability for validly quantifying emerging skills, and potential for standardisation for clinical use and rigorous research design.

A Comparison of the Clinical Presentation of Preterm Birth and Autism Spectrum Disorder: Commonalities and Distinctions in Children Under 3

Premature infants and infants later diagnosed with autism spectrum disorder (ASD) share many commonalities in clinical presentations. However, prematurity and ASD also have differences in clinical presentation. These overlapping phenotypes can lead to misdiagnoses of ASD or missing a diagnosis of ASD in preterm infants. We document these commonalities and differences in various developmental domains with the hope of aiding in the accurate early detection of ASD and timely intervention implementation in children born premature. Given the degree of similarities in presentation, evidence-based interventions designed specifically for preterm toddlers or toddlers with ASD may ultimately aid both populations.

Toddlers at Elevated Likelihood for Autism: Exploring Sensory and Language Treatment Predictors

Baseline child characteristics may predict treatment outcomes in children with or at elevated likelihood of developing autism (EL-ASD). Little is known about the role of child sensory and language features on treatment outcome. Participants were randomly assigned to a parent-mediated intervention or control condition. Analyses explored the relationship between baseline child sensory and language characteristics and changes in ASD symptoms over approximately 9 months. Higher baseline sensory hyporeactivity was significantly related to less improvement in social communication (SC) for the treatment group only. More baseline atypical vocalizations were significantly related to less improvement on SC across treatment and control groups. This work provides an initial framework to encourage the tailoring of interventions for EL-ASD children, suggesting sensory reactivity and atypical vocalizations may be useful behaviors to consider in treatment planning.

Inter-rater reliability in classification of canonical babbling status based on canonical babbling ratio in infants with isolated cleft palate randomised to Timing of Primary Surgery for Cleft Palate (TOPS)

Canonical babbling (CB) is commonly defined as present when at least 15% of all syllables produced are canonical, in other words a canonical babbling ratio (CBR) ≥0.15. However, there is limited knowledge about inter-rater reliability in classification of CB status based on CBR and inter-rater differences in assessment of CBR. We investigated inter-rater reliability of experienced Speech Language Therapists (SLTs) on: classification of CB status based on CBR ≥ 0.15, CBRs and the total number of syllables per infant used to calculate CBR.Each infant (n = 484) was video-recorded at a clinical site in play interaction with their parent as part of the randomised controlled trial Timing of Primary Surgery for Cleft Palate. Each recording was subsequently assessed by three independent SLTs, from a pool of 29 SLTs. They assessed the recordings in real time.The three assessing SLTs agreed in classification of CB status in 423 (87.4%) infants, with higher complete agreement for canonical (91%; 326/358) than non-canonical (77%; 97/126). The average difference in CBR and total number of syllables identified between the SLT assessments of each infant was 0.12 and 95, respectively.This study provided new evidence that one trained SLT can reliably classify CB status (CBR ≥ 0.15) in real time when there is clear distinction between the observed CBR and the boundary (0.15); however, when the observed CBR approaches the boundary multiple SLT assessments are beneficial. Thus, we recommend to include assessment of inter-rater reliability, if the purpose is to compare CBR and total syllable count across infants or studies.Trial registration number here: www.clinicaltrials.gov, identifier NCT00993551.

A Probe Study on Vocal Development in Two Infants at Risk for Cerebral Palsy

The present work examined canonical babbling ratios longitudinally as a measure of onset and consolidation of canonical babbling in two infants at risk of cerebral palsy (CP) between 5 and 16 months. Ten typically developing infants were included for comparison at 6, 9, 12, and 16-19 months. Canonical babbling ratios (CBRs) were calculated from 5-min segments, and follow-up diagnostic outcomes were collected between 24 and 33 months. The two infants at risk demonstrated low CBR growth trajectories compared to the typical infant group, and slightly different patterns of consolidation. The two infants at risk were later diagnosed with different levels of CP and speech impairment severity. All infants demonstrated greater variability than expected. Studying canonical babbling and other prelinguistic milestones in this population may inform our perspective of the involvement of the motor system in the vocal domain. Additional implications on the analysis of canonical babbling using all-day home recordings are discussed.

Emerging Verbal Functions in Early Infancy: Lessons from Observational and Computational Approaches on Typical Development and Neurodevelopmental Disorders

OBJECTIVES

Research on typically developing (TD) children and those with neurodevelopmental disorders and genetic syndromes was targeted. Specifically, studies on autism spectrum disorder, Down syndrome, Rett syndrome, fragile X syndrome, cerebral palsy, Angelman syndrome, tuberous sclerosis complex, Williams-Beuren syndrome, Cri-du-chat syndrome, Prader-Willi syndrome, and West syndrome were searched. The objectives are to review observational and computational studies on the emergence of (pre-)babbling vocalisations and outline findings on acoustic characteristics of early verbal functions.

METHODS

A comprehensive review of the literature was performed including observational and computational studies focusing on spontaneous infant vocalisations at the pre-babbling age of TD children, individuals with genetic or neurodevelopmental disorders.

RESULTS

While there is substantial knowledge about early vocal development in TD infants, the pre-babbling phase in infants with neurodevelopmental and genetic syndromes is scarcely scrutinised. Related approaches, paradigms, and definitions vary substantially and insights into the onset and characteristics of early verbal functions in most above-mentioned disorders are missing. Most studies focused on acoustic low-level descriptors (e.g. fundamental frequency) which bore limited clinical relevance. This calls for computational approaches to analyse features of infant typical and atypical verbal development.

CONCLUSIONS

Pre-babbling vocalisations as precursor for future speech-language functions may reveal valuable signs for identifying infants at risk for atypical development. Observational studies should be complemented by computational approaches to enable in-depth understanding of the developing speech-language functions. By disentangling features of typical and atypical early verbal development, computational approaches may support clinical screening and evaluation.

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.

Advanced paternal age diversifies individual trajectories of vocalization patterns in neonatal mice

Infant crying is a communicative behavior impaired in neurodevelopmental disorders (NDDs). Because advanced paternal age is a risk factor for NDDs, we performed computational approaches to evaluate how paternal age affected vocal communication and body weight development in C57BL/6 mouse offspring from young and aged fathers. Analyses of ultrasonic vocalization (USV) consisting of syllables showed that advanced paternal age reduced the number and duration of syllables, altered the syllable composition, and caused lower body weight gain in pups. Pups born to young fathers had convergent vocal characteristics with a rich repertoire, whereas those born to aged fathers exhibited more divergent vocal patterns with limited repertoire. Additional analyses revealed that some pups from aged fathers displayed atypical USV trajectories. Thus, our study indicates that advanced paternal age has a significant effect on offspring's vocal development. Our computational analyses are effective in characterizing altered individual diversity.

Lexical Acquisition and Phonological Development in Minimally Verbal Children With Autism Spectrum Disorders

PURPOSE

This study examines two components of lexical acquisition and phonological development that occur during the first 50-word stage of language development in neurotypical (NT) children. One component is how children learn words based on their existing speech sound inventories (i.e., in-phonology and out-of-phonology word learning). The other component is the relationship between the children's number of words and the number of phonemes in their speech sound inventories. The goal of this study is to determine if the same two components occur in children with autism spectrum disorders (ASDs) who are older than their NT peers but are in the same stage of lexical development.

METHOD

This study involved 20 minimally verbal children with ASDs, ages 28-72 months, who produced five to 50 spoken words. The children's spoken words were obtained from the MacArthur-Bates Communicative Development Inventories. The speech sound inventories were obtained from the utterances produced during assessment/play sessions with the children. The children's spoken words from the Communicative Development Inventories (CDI) were categorized as either in-phonology or out-of-phonology based on whether the words began with a phoneme in the child's existing speech sound inventory. Additionally, the children's number of spoken words on the CDI was compared to the number of phonemes in their speech sound inventories.

RESULTS

The children in this study produced in-phonology words more often than out-of-phonology words (z = -3.922; p < .001). Moreover, there was a moderate positive correlation between the children's number of spoken words and the number of phonemes in their speech sound inventories (r = .534, p = .019).

CONCLUSIONS

The relationship between lexical acquisition and phonological development appears to exist for the children in this study, who are in the first 50-word stage of development. Clinical implications for increasing the expressive language of children with ASDs were discussed.

Infants later diagnosed with autism have lower canonical babbling ratios in the first year of life

BACKGROUND

Canonical babbling-producing syllables with a mature consonant, full vowel, and smooth transition-is an important developmental milestone that typically occurs in the first year of life. Some studies indicate delayed or reduced canonical babbling in infants at high familial likelihood for autism spectrum disorder (ASD) or who later receive an ASD diagnosis, but evidence is mixed. More refined characterization of babbling in the first year of life in infants with high likelihood for ASD is needed.

METHODS

Vocalizations produced at 6 and 12 months by infants (n = 267) taking part in a longitudinal study were coded for canonical and non-canonical syllables. Infants were categorized as low familial likelihood (LL), high familial likelihood diagnosed with ASD at 24 months (HL-ASD) or not diagnosed (HL-Neg). Language delay was assessed based on 24-month expressive and receptive language scores. Canonical babble ratio (CBR) was calculated by dividing the number of canonical syllables by the number of total syllables. Generalized linear (mixed) models were used to assess the relationship between group membership and CBR, controlling for site, sex, and maternal education. Logistic regression was used to assess whether canonical babbling ratios at 6 and 12 months predict 24-month diagnostic outcome.

RESULTS

No diagnostic group differences in CBR were detected at 6 months, but HL-ASD infants produced significantly lower CBR than both the HL-Neg and LL groups at 12 months. HL-Neg infants with language delay also showed reduced CBR at 12 months. Neither 6- nor 12-month CBR was significant predictors of 24-month diagnostic outcome (ASD versus no ASD) in logistic regression.

LIMITATIONS

Small numbers of vocalizations produced by infants at 6 months may limit the reliability of CBR estimates. It is not known if results generalize to infants who are not at high familial likelihood, or infants from more diverse racial and socioeconomic backgrounds.

CONCLUSIONS

Lower canonical babbling ratios are apparent by the end of the first year of life in ASD regardless of later language delay, but are also observed for infants with later language delay without ASD. Canonical babbling may lack specificity as an early marker when used on its own.

Vocalisation Repertoire at the End of the First Year of Life: An Exploratory Comparison of Rett Syndrome and Typical Development

Rett syndrome (RTT) is a rare, late detected developmental disorder associated with severe deficits in the speech-language domain. Despite a few reports about atypicalities in the speech-language development of infants and toddlers with RTT, a detailed analysis of the pre-linguistic vocalisation repertoire of infants with RTT is yet missing. Based on home video recordings, we analysed the vocalisations between 9 and 11 months of age of three female infants with typical RTT and compared them to three age-matched typically developing (TD) female controls. The video material of the infants had a total duration of 424 min with 1655 infant vocalisations. For each month, we (1) calculated the infants' canonical babbling ratios with CBRUTTER, i.e., the ratio of number of utterances containing canonical syllables to total number of utterances, and (2) classified their pre-linguistic vocalisations in three non-canonical and four canonical vocalisation subtypes. All infants achieved the milestone of canonical babbling at 9 months of age according to their canonical babbling ratios, i.e. CBRUTTER ≥ 0.15. We revealed overall lower CBRsUTTER and a lower proportion of canonical pre-linguistic vocalisations consisting of well-formed sounds that could serve as parts of target-language words for the RTT group compared to the TD group. Further studies with more data from individuals with RTT are needed to study the atypicalities in the pre-linguistic vocalisation repertoire which may portend the later deficits in spoken language that are characteristic features of RTT.

Using big data from long-form recordings to study development and optimize societal impact

Big data are everywhere. In this chapter, we focus on one source: long-form, child-centered recordings collected using wearable technologies. Because these recordings are simultaneously unobtrusive and encompassing, they may be a breakthrough technology for clinicians and researchers from several diverse fields. We demonstrate this possibility by outlining three applications for the recordings-clinical treatment, large-scale interventions, and language documentation-where we see the greatest potential. We argue that incorporating these recordings into basic and applied research will result in more equitable treatment of patients, more reliable measurements of the effects of interventions on real-world behavior, and deeper scientific insights with less observational bias. We conclude by outlining a proposal for a semistructured online platform where vast numbers of long-form recordings could be hosted and more representative, less biased algorithms could be trained.

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.

Exploring Growth in Expressive Communication of Infants and Toddlers With Autism Spectrum Disorder

One of the earliest indicators of autism spectrum disorder (ASD) is delay in language and social communication. Despite consensus on the benefits of earlier diagnosis and intervention, our understanding of the language growth of children with ASD during the first years of life remains limited. Therefore, this study compared communication growth patterns of infants and toddlers with ASD to growth benchmarks of a standardized language assessment. We conducted a retrospective analysis of growth on the Early Communication Indicator (ECI) of 23 infants and toddlers who received an ASD diagnosis in the future. At 42 months of age, children with ASD had significantly lower rates of gestures, single words, and multiple words, but significantly higher rates of nonword vocalizations. Children with ASD had significantly slower growth of single and multiple words, but their rate of vocalization growth was significantly greater than benchmark. Although more research is needed with larger samples, because the ECI was designed for practitioners to monitor children's response to intervention over time, these findings show promise for the ECI's use as a progress monitoring measure for young children with ASD. Limitations and the need for future research are discussed.

Clinical utilisation of the Infant Monitor of vocal Production (IMP) for early identification of communication impairment in young infants at-risk of cerebral palsy: a prospective cohort study

AIM

To report prospective longitudinal data of early vocaliszations of infants identified "at-risk" of cerebral palsy (CP) for early identification of communication impairment.

METHOD

This case-control longitudinal prospective cohort study reports on the assessment of 36 infants, 18 identified as at-risk of CP at the time of enrolment and 18 typically developing (TD) children, at three time points: 6 months, 9 months and 12 months of age, Data were obtained through criterion and norm referenced assessments of vocaliszation behaviors.

RESULTS

Early vocal behaviors of infants identified as at-risk of CP did not differ from their age matched peers at 6 months of age, however, significant group differences emerged at 9 and 12 months when pre-canonical and canonical babble typically emerge. Generalized linear mixed models analysis showed that the rate of development of early language ability and more complex speech-related vocal behaviors was slower for infants at risk of CP when compared to TD infants, with over 75% of infants with CP showing below normal vocal production and impaired language by 12 months of age.

INTERPRETATION

Our data suggest characteristics of infant vocalizations associated with pre-canonical and canonical babbling provide a strong evidence base for predicting communication outcomes in infants at risk of CP.

Perspectives on the origin of language: Infants vocalize most during independent vocal play but produce their most speech-like vocalizations during turn taking

A growing body of research emphasizes both endogenous and social motivations in human vocal development. Our own efforts seek to establish an evolutionary and developmental perspective on the existence and usage of speech-like vocalizations ("protophones") in the first year of life. We evaluated the relative occurrence of protophones in 40 typically developing infants across the second-half year based on longitudinal all-day recordings. Infants showed strong endogenous motivation to vocalize, producing vastly more protophones during independent vocal exploration and play than during vocal turn taking. Both periods of vocal play and periods of turn-taking corresponded to elevated levels of the most advanced protophones (canonical babbling) relative to periods without vocal play or without turn-taking. Notably, periods of turn taking showed even more canonical babbling than periods of vocal play. We conclude that endogenous motivation drives infants' tendencies to explore and display a great number of speech-like vocalizations, but that social interaction drives the production of the most speech-like forms. The results inform our previously published proposal that the human infant has been naturally selected to explore protophone production and that the exploratory inclination in our hominin ancestors formed a foundation for language.

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.

The maturational gradient of infant vocalizations: Developmental stages and functional modules

Stage models have been influential in characterizing infant vocalizations in the first year of life. These models are basically descriptive and do not explain why certain types of vocal behaviors occur within a particular stage or why successive patterns of vocalization occur. This review paper summarizes and elaborates a theory of Developmental Functional Modules (DFMs) and discusses how maturational gradients in the DFMs explain age typical vocalizations as well as the transitions between successive stages or other static forms. Maturational gradients are based on biological processes that effect the reconfiguration and remodeling of the respiratory, laryngeal, and craniofacial systems during infancy. From a dynamic systems perspective, DFMs are part of a complex system with multiple degrees of freedom that can achieve stable performance with relatively few control variables by relying on principles such as synergies, self-organization, nonlinear performance, and movement variability.

Isolation-Induced Ultrasonic Vocalization in Environmental and Genetic Mice Models of Autism

Studies in rodent models suggest that calls emitted by isolated pups serve as an early behavioral manifestation of communication deficits and autistic like behavior. Previous studies in our labs showed that gestational exposure to the pesticide chlorpyrifos (CPF) and the Mthfr-knock-out mice are associated with impaired social preference and restricted or repetitive behavior. To extend these studies, we examine how pup communication via ultrasonic vocalizations is altered in these ASD models. We implemented an unsupervised hierarchical clustering method based on the spectral properties of the syllables in order to exploit syllable classification to homogeneous categories while avoiding over-categorization. Comparative exploration of the spectral and temporal aspects of syllables emitted by pups in two ASD models point to the following: (1) Most clusters showed a significant effect of the ASD factor on the start and end frequencies and bandwidth and (2) The highest percent change due to the ASD factor was on the bandwidth and duration. In addition, we found sex differences in the spectral and temporal properties of the calls in both control groups as well as an interaction between sex and the gene/environment factor. Considering the basal differences in the characteristics of syllables emitted by pups of the C57Bl/6 and Balb/c strains used as a background in the two models, we suggest that the above spectral-temporal parameters start frequency, bandwidth, and duration are the most sensitive USV features that may represent developmental changes in ASD models.

Early Vocal Development in Tuberous Sclerosis Complex

BACKGROUND

Our goal was to assess for the first time early vocalizations as precursors to speech in audio-video recordings of infants with tuberous sclerosis complex (TSC).

METHODS

We randomly selected 40 infants with TSC from the TSC Autism Center of Excellence Research Network dataset. Using human observers, we analyzed 74 audio-video recordings within a flexible software-based coding environment. During the recordings, infants were engaged in developmental testing. We determined syllables per minute (volubility), the number of consonant-vowel combinations, such as 'ba' (canonical babbling), and the canonical babbling ratio (canonical syllables/total syllables) and compared the data with two groups of typically developing (TD) infants. One comparison group's data had come from a laboratory setting, while the other's had come from all-day Language Environment Analysis recordings at home.

RESULTS

Compared with TD infants in laboratory and all-day Language Environment Analysis recordings, entry into the canonical babbling stage was delayed in the majority of infants with TSC, and the canonical babbling ratio was low (TD mean = 0.346, SE = 0.19; TSC mean = 0.117, SE = 0.023). Volubility level in infants with TSC was less than half that of TD infants (TD mean = 9.82, SE = 5.78; TSC mean = 3.99, SE = 2.16).

CONCLUSIONS

Entry into the canonical stage and other precursors of speech development were delayed in infants with TSC and may signal poor language and developmental outcomes. Future studies are planned to assess prediction of language and developmental outcomes using these measures in a larger sample and in more precisely comparable recording circumstances.

Early Vocal Development in Tuberous Sclerosis Complex

BACKGROUND

Our goal was to assess for the first time early vocalizations as precursors to speech in audio-video recordings of infants with tuberous sclerosis complex (TSC).

METHODS

We randomly selected 40 infants with TSC from the TSC Autism Center of Excellence Research Network dataset. Using human observers, we analyzed 74 audio-video recordings within a flexible software-based coding environment. During the recordings, infants were engaged in developmental testing. We determined syllables per minute (volubility), the number of consonant-vowel combinations, such as 'ba' (canonical babbling), and the canonical babbling ratio (canonical syllables/total syllables) and compared the data with two groups of typically developing (TD) infants. One comparison group's data had come from a laboratory setting, while the other's had come from all-day Language Environment Analysis recordings at home.

RESULTS

Compared with TD infants in laboratory and all-day Language Environment Analysis recordings, entry into the canonical babbling stage was delayed in the majority of infants with TSC, and the canonical babbling ratio was low (TD mean = 0.346, SE = 0.19; TSC mean = 0.117, SE = 0.023). Volubility level in infants with TSC was less than half that of TD infants (TD mean = 9.82, SE = 5.78; TSC mean = 3.99, SE = 2.16).

CONCLUSIONS

Entry into the canonical stage and other precursors of speech development were delayed in infants with TSC and may signal poor language and developmental outcomes. Future studies are planned to assess prediction of language and developmental outcomes using these measures in a larger sample and in more precisely comparable recording circumstances.

Longitudinal Study of Vocal Development and Language Environments in Infants With Cleft Palate

OBJECTIVE

This study investigated vocalization and language environment longitudinally in infants with cleft palate (CP) based on day-long audio recordings collected in their natural environments.

DESIGN

Language Environment Analysis (LENA) data from all-day recordings at home were collected at 3-month intervals for infants from 4-6 to 16-18 months of age. The recordings were analyzed using experimentally blinded human coding as well as LENA automated analysis.

PARTICIPANTS

Ten infants with CP (± cleft lip) and 10 age-matched infants without CP.

MAIN OUTCOME MEASURES

Several measurements were obtained from the LENA automated analysis software. In addition, human coded measurements of vocalization and language environment, including the true canonical babbling ratio and the infant-directed speech ratio, were analyzed for each time point of data collection for each infant. Statistical analyses were performed to conduct group and age comparisons for each measure of vocalization and language environment.

RESULTS

No group differences emerged in number of syllables produced. Infants with CP exhibited late onset and fewer productions of canonical syllables compared to infants without CP. Infants with CP did not show significant differences from infants without CP in measures related to language environment across ages.

CONCLUSION

This study provides detailed information through naturalistic all-day home recordings about vocal development and early language environments in infants with CP before and after palatal repair. Clinical implications for early intervention are discussed.

Effectiveness of Responsivity Intervention Strategies on Prelinguistic and Language Outcomes for Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Group and Single Case Studies

We conducted a systematic review to identify randomized controlled trials (RCTs) and single case research design (SCRD) studies of children with autism spectrum disorder that evaluate the effectiveness of responsivity intervention techniques for improving prelinguistic and/or language outcomes. Mean effect sizes were moderate and large for RCTs (33 studies; g = 0.36, 95% CI [0.21, 0.51]) and SCRD (34 studies; between-case standardized mean difference = 1.20, 95% CI [0.87, 1.54]) studies, respectively. Visual analysis (37 studies) revealed strong evidence of a functional relation for 45% of the opportunities and no evidence for 53%. Analyses of moderator effects and study quality are presented. Findings provide support for responsivity intervention strategies with more robust support for context-bound outcomes than more generalized outcomes.

Canonical babbling ratio - Concurrent and predictive evaluation of the 0.15 criterion

INTRODUCTION

Canonical babbling ratio (CBR) is a commonly used measure to quantify canonical babbling (CB), and 0.15 is the commonly accepted criterion for the canonical babbling stage. However, this has not been thoroughly investigated. The aim of this study was to evaluate the validity of this criterion using concurrent and predictive comparisons.

METHODS

Longitudinal data from 50 children recruited in different clinical projects were used. At 10 months of age, CBR was calculated based on counted utterances from audio-video recorded parent-child interactions. The videos were also assessed by CB observation, where an observer made an overall judgement on whether the child was in the canonical babbling stage or not. For the concurrent evaluation, CBR was compared to CB observation as a reference test, using area under the curve (AUC). The criterion resulting in the best combination of sensitivity and specificity was identified using positive likelihood ratios. In the predictive comparisons CBR was analyzed as a predictor of speech/language difficulties at 30-36 months. Participants presenting with difficulties in consonant production and/or parent-reported vocabulary were considered to have speech/language difficulties. Sensitivity and specificity were compared for CBR using the 0.15 criterion and the new criterion identified in this study.

RESULTS

An AUC of 0.87 indicated that CBR is a valid measure of canonical babbling in 10-month-old children. The best combination of sensitivity and specificity was found at a criterion of 0.14 (sensitivity 0.96, specificity 0.70). In the predictive comparison, CBR with a 0.14 or 0.15 criterion revealed the same sensitivity (0.71) but 0.14 showed a slightly better specificity (0.52 versus 0.42).

CONCLUSIONS

CBR is a valid measure of CB (at 10 months). However, when using CBR to classify children's babbling as canonical or non-canonical, researchers need to carefully consider the implications of the chosen criterion.

Vocal development in a large-scale crosslinguistic corpus

This study evaluates whether early vocalizations develop in similar ways in children across diverse cultural contexts. We analyze data from daylong audio recordings of 49 children (1-36 months) from five different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations contained canonical transitions or not (e.g., "ba" vs. "ee"). Results revealed that the proportion of clips reported to contain canonical transitions increased with age. Furthermore, this proportion exceeded 0.15 by around 7 months, replicating and extending previous findings on canonical vocalization development but using data from the natural environments of a culturally and linguistically diverse sample. This work explores how crowdsourcing can be used to annotate corpora, helping establish developmental milestones relevant to multiple languages and cultures. Lower inter-annotator reliability on the crowdsourcing platform, relative to more traditional in-lab expert annotators, means that a larger number of unique annotators and/or annotations are required, and that crowdsourcing may not be a suitable method for more fine-grained annotation decisions. Audio clips used for this project are compiled into a large-scale infant vocalization corpus that is available for other researchers to use in future work.

Should Echolalia Be Considered a Phonic Stereotypy? A Narrative Review

The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) defines echolalia as a pathological, parrotlike, and apparently senseless repetition (echoing) of a word or phrase just uttered by another person and classifies this condition among the “restrictive and repetitive behaviours” of Autism Spectrum Disorder (ASD). The authors reviewed the existing literature on echolalia and its role in the development of children with ASD. Current conceptualizations include echolalia among repetitive behaviors and stereotypies and thus interpret this symptom as lacking any communicative significance, with negative effects on learning and sensory processing. Echoic behaviors, however, have been described in neurotypical infants and children as having a substantial effect on the consequent development of language and communication. Relevant research has documented a functional role of echolalia in ASD children as well since it facilitates the acquisition of verbal competencies and affords a higher degree of semantic generalization. This developmental function could be restricted to specific contexts. Considering echolalia as stereotypy and treating it as a disturbing symptom could impair the development of ASD-specific learning and communication processes. In light of this evidence, the authors propose a different conceptualization of echolalia and suggest that this symptom be considered among atypical communication patterns in children with ASD, with implications for treatment and prognosis.

Abnormal Behavior and Cortical Connectivity Deficits in Mice Lacking Usp9x

Genetic association studies have identified many factors associated with neurodevelopmental disorders such as autism spectrum disorder (ASD). However, the way these genes shape neuroanatomical structure and connectivity is poorly understood. Recent research has focused on proteins that act as points of convergence for multiple factors, as these may provide greater insight into understanding the biology of neurodevelopmental disorders. USP9X, a deubiquitylating enzyme that regulates the stability of many ASD-related proteins, is one such point of convergence. Loss of function variants in human USP9X lead to brain malformations, which manifest as a neurodevelopmental syndrome that frequently includes ASD, but the underlying structural and connectomic abnormalities giving rise to patient symptoms is unknown. Here, we analyzed forebrain-specific Usp9x knockout mice (Usp9x-/y) to address this knowledge gap. Usp9x-/y mice displayed abnormal communication and social interaction behaviors. Moreover, the absence of Usp9x culminated in reductions to the size of multiple brain regions. Diffusion tensor magnetic resonance imaging revealed deficits in all three major forebrain commissures, as well as long-range hypoconnectivity between cortical and subcortical regions. These data identify USP9X as a key regulator of brain formation and function, and provide insights into the neurodevelopmental syndrome arising as a consequence of USP9X mutations in patients.

Adding a fourth rater to three had little impact in pre-linguistic outcome classification

The consequence of differing levels of agreement across raters is rarely studied. Subsequently, knowledge is limited on how number of raters affects the outcome. The present study aimed to examine the impact on pre-linguistic outcome classifications of 12-month-old infants when using four raters compared to three. Thirty experienced Speech and Language Therapists (SLTs) from five countries assessed 20 minute video recordings of four 12-month-old infants during a play session with a parent. One recording was assessed twice. A naturalistic listening method in real time was used. This involved: (1) assessing, each syllable as canonical or non-canonical, and (2) following the recording, assessing if the infant was babbling canonically and listing the syllables the infant produced with command. The impact that four raters had on outcome, compared to three, was explored by classifying the outcome based on all possible combinations of three raters and determining the frequency that the outcome assessment changed when a fourth assessor was added. Results revealed that adding a fourth rater had a minimal impact on canonical babbling ratio assessment. Presence/absence of canonical babbling and size of consonant inventory showed a negligible impact on three out of four recordings, whereas the size of syllable inventory and presence/absence of canonical babbling was minimally affected in one recording by adding a fourth rater. In conclusion, adding a forth rater in assessment of pre-linguistic utterances in 12-month-old infants with naturalistic assessment in real time does not affect outcome classifications considerably. Thus, using three raters, as opposed to four, is recommended.

Functionally Flexible Signaling and the Origin of Language

At the earliest break of ancient hominins from their primate relatives in vocal communication, we propose a selection pressure on vocal fitness signaling by hominin infants. Exploratory vocalizations, not tied to expression of distress or immediate need, could have helped persuade parents of the wellness and viability of the infants who produced them. We hypothesize that hominin parents invested more in infants who produced such signals of fitness plentifully, neglecting or abandoning them less often than infants who produced the sounds less frequently. Selection for such exploratory vocalization provided a critically important inclination and capability relevant to language, we reason, because the system that encouraged spontaneous vocalization also made vocalization functionally flexible to an extent that has not been observed in any other animal. Although this vocal flexibility did not by itself create language, it provided an essential foundation upon which language would evolve through a variety of additional steps. In evaluating this speculation, we consider presumable barriers to evolving language that are thought to be implications of Darwinian Theory. It has been claimed that communication always involves sender self-interest and that self-interest leads to deceit, which is countered through clever detection by receivers. The constant battle of senders and receivers has been thought to pose an insuperable challenge to honest communication, which has been viewed as a requirement of language. To make communication honest, it has been proposed that stable signaling requires costly handicaps for the sender, and since language cannot entail high cost, the reasoning has suggested an insurmountable obstacle to the evolution of language. We think this presumed honesty barrier is an illusion that can be revealed by recognition of the fact that language is not inherently honest and in light of the distinction between illocutionary force and semantics. Our paper also considers barriers to the evolution of language (not having to do with honesty) that we think may have actually played important roles in preventing species other than humans from evolving language.

Emerging behavioral and neuroimaging biomarkers for early and accurate characterization of autism spectrum disorders: a systematic review

The possibility of early treatment and a better outcome is the direct product of early identification and characterization of any pathological condition. Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in social communication, restricted, and repetitive patterns of behavior. In recent times, various tools and methods have been developed for the early identification and characterization of ASD features as early as 6 months of age. Thorough and exhaustive research has been done to identify biomarkers in ASD using noninvasive neuroimaging and various molecular methods. By employing advanced assessment tools such as MRI and behavioral assessment methods for accurate characterization of the ASD features and may facilitate pre-emptive interventional and targeted therapy programs. However, the application of advanced quantitative MRI methods is still confined to investigational/laboratory settings, and the clinical implication of these imaging methods in personalized medicine is still in infancy. Longitudinal research studies in neurodevelopmental disorders are the need of the hour for accurate characterization of brain-behavioral changes that could be monitored over a period of time. These findings would be more reliable and consistent with translating into the clinics. This review article aims to focus on the recent advancement of early biomarkers for the characterization of ASD features at a younger age using behavioral and quantitative MRI methods.

Früherkennung von Entwicklungsstörungen: Kanonisches Lallen (k)‌ein diagnostischer Marker‍(!)?

Zusammenfassung. Theoretischer Hintergrund: Forschungsergebnisse zum frühen Spracherwerb bei Kindern mit spät erkannten Entwicklungsstörungen sind inkonsistent und angesichts unterschiedlicher Forschungsparadigmen und Definitionen nur bedingt vergleichbar. Fragestellung: Ziel dieser Übersichtsarbeit ist es, das Potenzial früher verbaler Fähigkeiten, vor allem des kanonischen Lallens, als Marker zur Früherkennung von Autismus-Spektrum-Störung, Rett-Syndrom und Fragilem-X-Syndrom zu beschreiben. Methode: Übersichtsarbeit über retrospektive und prospektive Studien zu frühen verbalen Fähigkeiten in der Prodromalphase dieser Störungsbilder. Ergebnisse: Einige Kinder mit spät erkannten Entwicklungsstörungen erwerben das kanonische Lallen nach dem kritischen Zeitfenster von 6 bis 10 Monaten und/oder haben oft qualitative Veränderungen in ihren Lautäußerungen. Diskussion und Schlussfolgerung: Eine abweichende Entwicklung des kanonischen Lallens kann auf spätere atypische Entwicklung hinweisen. Als funktioneller Marker für die spezifische Früherkennung von Entwicklungsstörungen scheint dieser Erwerbsmeilenstein jedoch nicht geeignet. Linguistische und signalbasierte Detailanalysen frühkindlicher Vokalisationen könnten zukünftig einen entscheidenden Beitrag hierzu leisten.

Efficient Collection and Representation of Preverbal Data in Typical and Atypical Development

Human preverbal development refers to the period of steadily increasing vocal capacities until the emergence of a child’s first meaningful words. Over the last decades, research has intensively focused on preverbal behavior in typical development. Preverbal vocal patterns have been phonetically classified and acoustically characterized. More recently, specific preverbal phenomena were discussed to play a role as early indicators of atypical development. Recent advancements in audio signal processing and machine learning have allowed for novel approaches in preverbal behavior analysis including automatic vocalization-based differentiation of typically and atypically developing individuals. In this paper, we give a methodological overview of current strategies for collecting and acoustically representing preverbal data for intelligent audio analysis paradigms. Efficiency in the context of data collection and data representation is discussed. Following current research trends, we set a special focus on challenges that arise when dealing with preverbal data of individuals with late detected developmental disorders, such as autism spectrum disorder or Rett syndrome.

The role of caregiver speech in supporting language development in infants and toddlers with autism spectrum disorder

Parents play an essential role in supporting child development by providing a safe home, proper nutrition, and rich educational opportunities. In this article we focus on the role of caregiver speech in supporting development of young children with autism spectrum disorder (ASD). We review studies from typically developing children and children with autism showing that rich and responsive caregiver speech supports language development. Autism intervention studies that target caregiver speech are reviewed as are recent scientific advances from studies of typical development. The strengths and weakness of different techniques for collecting language data from caregivers and children are reviewed, and natural language samples are recommended as best practice for language research in autism. We conclude that caregivers play a powerful role in shaping their children's development and encourage researchers to adapt parent-mediated intervention studies to acknowledge individual differences in parents by using a personalized medicine approach.

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.

Assessment of prelinguistic vocalizations in real time: a comparison with phonetic transcription and assessment of inter-coder-reliability

This study investigated reliability of naturalistic listening in real time (NLRT) compared to phonetic transcription. Speech pathology students with brief training in NLRT assessed prelinguistic syllable inventory size and specific syllable types in typically developing infants. A second study also examined inter-coder reliability for canonical babbling, canonical babbling ratio and presence of oral stops in syllable inventory of infants with cleft palate, by means of NLRT. In study 1, ten students independently assessed prelinguistic samples of five 12-month-old typically developing infants using NLRT and phonetic transcription. Coders assessed syllable inventory size as more than twice as large using phonetic transcription as NLRT. Results showed a strong correlation between NLRT and phonetic transcription (syllables with more than five occurrences) for syllable inventory size (r = .60; p < .001). The methods showed similar results for inter-coder reliability of specific syllable types. In study 2, three other students assessed prelinguistic samples of twenty-eight 12-month-old infants with cleft palate by means of NLRT. Results revealed perfect inter-coder agreement for presence/absence of canonical babbling, strong correlations between the three coders' assessment of syllable inventory size (average r = .83; p < .001), but more inter-coder variability for agreement of specific syllable types. In conclusion, NLRT is a reliable method for assessing prelinguistic measures in infants with and without cleft palate with inter-coder agreement levels comparable to phonetic transcription for specific syllable types.

A retrospective video analysis of canonical babbling and volubility in infants later diagnosed with childhood apraxia of speech

Canonical babbling and volubility are common indicators of infant vocal development. If either indicator falls below values found in typical infants, it may be an early signal of a developmental disorder. The aim of this retrospective investigation was to examine home videos for the frequency of canonical babbles, age of canonical babbling onset, and overall volubility of eight infants later diagnosed with childhood apraxia of speech and compare these data to that of six typically developing infants as well as four infants later diagnosed with a speech sound disorder. Results revealed the infants later identified with childhood apraxia of speech used fewer canonical babbles, had later onset of canonical babbling, and fewer syllables per minute (volubility) than the comparison groups. These results suggest that infants later diagnosed with childhood apraxia of speech may be less adept in vocal exploration and in the production of canonical babbles, perhaps due to fewer opportunities for mapping articulatory movement with auditory speech sound outcomes.

Retrospective video analysis of the early speech sound development of infants and toddlers later diagnosed with lateralisation errors

Purpose: Although lateralisation errors (LEs) are a common speech sound disorder, no studies have examined their early development. The purpose of this exploratory small-scale investigation was to compare the early (birth-24 months) speech sound development between children later diagnosed with LEs and typically developing children.Method: This was a between-group case-controlled design with six monolingual English-speaking participants. Participants were White, non-Hispanic girls with at least one college-educated parent. As children, three had been diagnosed with lateralisation speech sound errors and three demonstrated typical speech sound development. Participants' parents provided home video-recordings of the participants as infants/toddlers between birth and age 2. These videos were then analysed for the amount, type and diversity of sounds, and canonical babbling onset.Result: There was no statistically significant between-group difference in the volubility (i.e. combined frequency of non-resonant and resonant utterances) or in the age at which [s] or [z] emerged. However, infants/toddlers who were later diagnosed with LEs showed reduced frequency/minute in production of resonant utterances and consonants (including [s, z]), used fewer different consonants/minute, and used fewer syllable shapes/minute compared to typically developing infants/toddlers. At 7-12 months, none of the infants/toddlers later diagnosed with LEs, but all participants in the comparison group had reached the canonical babbling stage.Conclusion: Children who have LEs may have had a less robust speech sound system as infants/toddlers than their typically developing peers. However, these findings must be considered with caution due to the significant limitations of this investigation.