Altered Gesture and Speech Production in ASD Detract from In-Person Communicative Quality

Speech and language patterns in autism: Towards natural language processing as a research and clinical tool

Speech and language differences have long been described as important characteristics of autism spectrum disorder (ASD). Linguistic abnormalities range from prosodic differences in pitch, intensity, and rate of speech, to language idiosyncrasies and difficulties with pragmatics and reciprocal conversation. Heterogeneity of findings and a reliance on qualitative, subjective ratings, however, limit a full understanding of linguistic phenotypes in autism. This review summarizes evidence of both speech and language differences in ASD. We also describe recent advances in linguistic research, aided by automated methods and software like natural language processing (NLP) and speech analytic software. Such approaches allow for objective, quantitative measurement of speech and language patterns that may be more tractable and unbiased. Future research integrating both speech and language features and capturing "natural language" samples may yield a more comprehensive understanding of language differences in autism, offering potential implications for diagnosis, intervention, and research.

Examining Phenotypical Heterogeneity and its Underlying Factors in Gesture Skills of Chinese Autistic Children: Clustering Analysis

PURPOSE

The heterogeneity of autism is well documented, but few studies have studied the heterogeneity of gesture production ability in autistic children. The present study aimed to identify subgroups of autistic children who displayed heterogeneous gesture production abilities and explore the underlying factors, including autism characteristics, intellectual ability, and language ability, that were associated with the heterogeneity.

METHODS

A total of 65 Chinese autistic children (mean age = 5;3) participated. Their autism characteristics and intellectual ability were assessed by standardized measurements. Language output and gesture production were captured from a parent-child interaction task.

RESULTS

We conducted a hierarchical cluster analysis and identified four distinct clusters. Cluster 1 and Cluster 2 both had low gesture production whereas Cluster 3 and Cluster 4 had high gesture production. Both Clusters 1 and 2 had relatively strong autism characteristics, in comparison to Clusters 3 and 4.

CONCLUSIONS

Our findings revealed that children with stronger autism characteristics may gesture less often than those with weaker characteristics. However, the relationship between language ability and intellectual ability and gesture production was not clear. These findings shed light on the directions of intervention on gesture production for autistic children, especially those with stronger autism characteristics.

The Development of Gesture Skills in Chinese Autistic Children: The Predictive Roles of Age and Language Ability

PURPOSE

Gesture delay in autistic infants and toddlers has been widely reported. The developmental trajectory of gesture production during early childhood is understudied. Thus, little is known about the possible changes of gesture production over time. The present study aimed to document the development of gesture production in autistic children and examine whether child-based factors (chronological age and initial language skills) predicted gesture development.

METHOD

A total of 33 Chinese-speaking autistic children (Mage = 56.39 months, SD = 8.54 months) played with their parents at four time points over a 9-month period. Their speech was transcribed, and their gestures were coded from parent-child interaction. Multilevel modeling analysis was used to investigate the development of gesture and its associated factors.

RESULTS

The total number of gestures produced by autistic children decreased over time. Among different factors, children's initial age significantly and negatively predicted children's gesture production, while initial language positively predicted children's gesture production.

CONCLUSIONS

Gesture delay persists in preschool age. The decline in gesture production was associated with children's age and initial language ability. These findings shed light on the difficulties surrounding gesture use in autistic children.

Can Natural Speech Prosody Distinguish Autism Spectrum Disorders? A Meta-Analysis

Natural speech plays a pivotal role in communication and interactions between human beings. The prosody of natural speech, due to its high ecological validity and sensitivity, has been acoustically analyzed and more recently utilized in machine learning to identify individuals with autism spectrum disorders (ASDs). In this meta-analysis, we evaluated the findings of empirical studies on acoustic analysis and machine learning techniques to provide statistically supporting evidence for adopting natural speech prosody for ASD detection. Using a random-effects model, the results observed moderate-to-large pooled effect sizes for pitch-related parameters in distinguishing individuals with ASD from their typically developing (TD) counterparts. Specifically, the standardized mean difference (SMD) values for pitch mean, pitch range, pitch standard deviation, and pitch variability were 0.3528, 0.6744, 0.5735, and 0.5137, respectively. However, the differences between the two groups in temporal features could be unreliable, as the SMD values for duration and speech rate were only 0.0738 and -0.0547. Moderator analysis indicated task types were unlikely to influence the final results, whereas age groups showed a moderating role in pooling pitch range differences. Furthermore, promising accuracy rates on ASD identification were shown in our analysis of multivariate machine learning studies, indicating averaged sensitivity and specificity of 75.51% and 80.31%, respectively. In conclusion, these findings shed light on the efficacy of natural prosody in identifying ASD and offer insights for future investigations in this line of research.

Sex differences in the temporal dynamics of autistic children's natural conversations

BACKGROUND

Autistic girls are underdiagnosed compared to autistic boys, even when they experience similar clinical impact. Research suggests that girls present with distinct symptom profiles across a variety of domains, such as language, which may contribute to their underdiagnosis. In this study, we examine sex differences in the temporal dynamics of natural conversations between naïve adult confederates and school-aged children with or without autism, with the goal of improving our understanding of conversational behavior in autistic girls and ultimately improving identification.

METHODS

Forty-five school-aged children with autism (29 boys and 16 girls) and 47 non-autistic/neurotypical (NT) children (23 boys and 24 girls) engaged in a 5-min "get-to-know-you" conversation with a young adult confederate that was unaware of children's diagnostic status. Groups were matched on IQ estimates. Recordings were time-aligned and orthographically transcribed by trained annotators. Several speech and pause measures were calculated. Groups were compared using analysis of covariance models, controlling for age.

RESULTS

Autistic girls used significantly more words than autistic boys, and produced longer speech segments than all other groups. Autistic boys spoke more slowly than NT children, whereas autistic girls did not differ from NT children in total word counts or speaking rate. Autistic boys interrupted confederates' speech less often and produced longer between-turn pauses (i.e., responded more slowly when it was their turn) compared to other children. Within-turn pause duration did not differ by group.

LIMITATIONS

Our sample included verbally fluent children and adolescents aged 6-15 years, so our study results may not replicate in samples of younger children, adults, and individuals who are not verbally fluent. The results of this relatively small study, while compelling, should be interpreted with caution and replicated in a larger sample.

CONCLUSION

This study investigated the temporal dynamics of everyday conversations and demonstrated that autistic girls and boys have distinct natural language profiles. Specifying differences in verbal communication lays the groundwork for the development of sensitive screening and diagnostic tools to more accurately identify autistic girls, and could inform future personalized interventions that improve short- and long-term social communication outcomes for all autistic children.

Conversational adaptation in children and teens with autism: Differences in talkativeness across contexts

Successful social communication is complex; it relies on effectively deploying and continuously revising one's behavior to fit the needs of a given conversation, partner, and context. For example, a skilled conversationalist may instinctively become less talkative with a quiet partner and more talkative with a chattier one. Prior research suggests that behavioral flexibility across social contexts can be a particular challenge for individuals with autism spectrum condition (ASC), and that difficulty adapting to the changing needs of a conversation contributes to communicative breakdowns and poor social outcomes. In this study, we examine whether reduced conversational adaptation, as measured by talkativeness, differentiates 48 verbally fluent children and teens with ASC from 50 neurotypical (NT) peers matched on age, intelligence quotient, and sex ratio. Participants completed the Contextual Assessment of Social Skills with two novel conversation partners. The first acted interested in the conversation and talked more (Interested condition), while the second acted bored and talked less (Bored condition). Results revealed that NT participants emulated their conversation partner's behavior by being more talkative in the Interested condition as compared to the Bored condition (z = 9.92, p < 0.001). In contrast, the ASC group did not differentially adapt their behavior to the Bored versus Interested context, instead remaining consistently talkative in both (p = 0.88). The results of this study have implications for understanding social communication and behavioral adaptation in ASC, and may be valuable for clinicians interested in improving conversational competence in verbally fluent individuals with autism. LAY SUMMARY: Social communication-including everyday conversations-can be challenging for individuals on the autism spectrum. In successful conversations, people tend to adjust aspects of their language to be more similar to their partners'. In this study, we found that children and teens with autism did not change their own talkativeness in response to a social partner who was more or less talkative, whereas neurotypical peers did. These findings have clinical implications for improving conversational competence in verbally fluent individuals with autism.

How do autistic adults use syntactic and prosodic cues to manage spoken discourse?

Discourse studies investigating differences in the socio-communicative profiles of autistic (ASD) and neurotypical (NT) individuals have mostly relied on orthographic transcriptions, without taking prosodic information into account. However, atypical prosody is ubiquitous in ASD and a more accurate representation of their discourse abilities should also include prosodic cues. This exploratory study addresses this gap by segmenting the spoken discourse of 12 ASD and NT adults using the framework of Basic Discourse Units (BDUs). BDUs result from the mapping of syntactic boundaries on prosodic units, which can coincide in different ways and are associated with different discourse strategies. We hypothesized that the discourse of ASD adults would display more atypical strategies than NT adults, reflecting a 'pedantic' style and more difficulties in managing ongoing discourse. While ASD adults did not produce more discourse units associated with didactic or pedantic strategies than NT adults, they did produce less units associated with strategies of interactional regulation. This study provides initial evidence that multidimensional linguistic units, such as BDUs can help differentiate speech delivery strategies of ASD adults from those of their NT peers, even based on simple prosodic cues like silent pauses.

The interaction of fine motor, gesture, and structural language skills: The case of autism spectrum disorder

Motor skill differences have been consistently reported in individuals with ASD. Associations between motor skill and social communication skills have been reported in both typical development (TD) and autism spectrum disorder (ASD). The current study extends these findings to characterize performance on a fine motor imitation task, probing skills as a predictor of social and communicative functioning, and co-speech gesture use. These research questions were addressed by a secondary analysis of data collected during a previous study characterizing a cohort of individuals who were diagnosed with ASD in early childhood but lost the autism diagnosis (LAD) by the time of adolescence. Fine motor imitation skills were compared between 14 individuals with LAD, 15 individuals with autism spectrum disorder (ASD), and 12 typically developing (TD) individuals. LAD and TD groups had more advanced fine motor imitation skills than the ASD group, and abilities were significantly associated with ASD symptoms and amount of gesture use (though there was a counterintuitive interaction between group and fine motor skill in the LAD and TD groups only, in which lower motor skills predicted more ASD symptoms; this relationship was of a small effect size and is likely driven by the compressed range of fine motor skills in these two groups). Findings suggest that fine motor skills normalize along with social communication skills and restricted and repetitive behaviors and interests in individuals who lose the ASD diagnosis, and that individuals with better fine motor abilities produce more co-speech gesture.

Brain mRNA Expression Associated with Cortical Volume Alterations in Autism Spectrum Disorder

Numerous studies report abnormal cerebral cortex volume (CCV) in autism spectrum disorder (ASD); however, genes related to CCV abnormalities in ASD remain largely unknown. Here, we identify genes associated with CCV alterations in ASD by performing spatial correlations between the gene expression of 6 donated brains and neuroimaging data from 1,404 ASD patients and 1,499 controls. Based on spatial correlations between gene expression and CCV differences from two independent meta-analyses and between gene expression and individual CCV distributions of 404 patients and 496 controls, we identify 417 genes associated with both CCV differences and individual CCV distributions. These genes are enriched for genetic association signals and genes downregulated in the ASD post-mortem brain. The expression patterns of these genes are correlated with brain activation patterns of language-related neural processes frequently impaired in ASD. These findings highlight a model whereby genetic risk impacts gene expression (downregulated), which leads to CCV alterations in ASD.

How do minimally verbal children and adolescents with autism spectrum disorder use communicative gestures to complement their spoken language abilities?

BACKGROUND AND AIMS

Prior work has examined how children and adolescents with autism spectrum disorder who are minimally verbal use their spoken language abilities during interactions with others. However, social communication includes other aspects beyond speech. To our knowledge, no studies have examined how minimally verbal children and adolescents with autism spectrum disorder are using their gestural communication during social interactions. Such work can provide important insights into how gestures may complement their spoken language abilities.

METHODS

Fifty minimally verbal children and adolescents with autism spectrum disorder participated (M _age = 12.41 years; 38 males). Gestural communication was coded from the Autism Diagnostic Observation Schedule. Children (n = 25) and adolescents (n = 25) were compared on their production of gestures, gesture-speech combinations, and communicative functions. Communicative functions were also assessed by the type of communication modality: gesture, speech, and gesture-speech to examine the range of communicative functions across different modalities of communication. To explore the role gestures may play the relation between speech utterances and gestural production was investigated.

RESULTS

Analyses revealed that (1) minimally verbal children and adolescents with autism spectrum disorder did not differ in their total number of gestures. The most frequently produced gesture across children and adolescents was a reach gesture, followed by a point gesture (deictic gesture), and then conventional gestures. However, adolescents produced more gesture-speech combinations (reinforcing gesture-speech combinations) and displayed a wider range of communicative functions. (2) Overlap was found in the types of communicative functions expressed across different communication modalities. However, requests were conveyed via gesture more frequently compared to speech or gesture-speech. In contrast, dis/agree/acknowledging and responding to a question posed by the conversational partner was expressed more frequently via speech compared to gesture or gesture-speech. (3) The total number of gestures was negatively associated with total speech utterances after controlling for chronological age, receptive communication ability, and nonverbal IQ.

CONCLUSIONS

Adolescents may be employing different communication strategies to maintain the conversational exchange and to further clarify the message they want to convey to the conversational partner. Although overlap occurred in communicative functions across gesture, speech, and gesture-speech, nuanced differences emerged in how often they were expressed across different modalities of communication. Given their speech production abilities, gestures may play a compensatory role for some individuals with autism spectrum disorder who are minimally verbal.

IMPLICATIONS

Findings underscore the importance of assessing multiple modalities of communication to provide a fuller picture of their social communication abilities. Our results identified specific communicative strengths and areas for growth that can be targeted and expanded upon within gesture and speech to optimize social communication development.

N400 amplitude, latency, and variability reflect temporal integration of beat gesture and pitch accent during language processing

This study examines how across-trial (average) and trial-by-trial (variability in) amplitude and latency of the N400 event-related potential (ERP) reflect temporal integration of pitch accent and beat gesture. Thirty native English speakers viewed videos of a talker producing sentences with beat gesture co-occurring with a pitch accented focus word (synchronous), beat gesture co-occurring with the onset of a subsequent non-focused word (asynchronous), or the absence of beat gesture (no beat). Across trials, increased amplitude and earlier latency were observed when beat gesture was temporally asynchronous with pitch accenting than when it was temporally synchronous with pitch accenting or absent. Moreover, temporal asynchrony of beat gesture relative to pitch accent increased trial-by-trial variability of N400 amplitude and latency and influenced the relationship between across-trial and trial-by-trial N400 latency. These results indicate that across-trial and trial-by-trial amplitude and latency of the N400 ERP reflect temporal integration of beat gesture and pitch accent during language comprehension, supporting extension of the integrated systems hypothesis of gesture-speech processing and neural noise theories to focus processing in typical adult populations.

Gesture Development, Caregiver Responsiveness, and Language and Diagnostic Outcomes in Infants at High and Low Risk for Autism

We investigated gesture production in infants at high and low risk for autism spectrum disorder (ASD) and caregiver responsiveness between 12 and 24 months of age and assessed the extent to which early gesture predicts later language and ASD outcomes. Participants included 55 high-risk infants, 21 of whom later met criteria for ASD, 34 low-risk infants, and their caregivers. Results indicated that (a) infants with ASD outcomes used fewer gestures and a lower proportion of developmentally advanced gesture-speech combinations; (b) caregivers of all the infants provided similar rates of contingent responses to their infants' gestures; and (c) gesture production at 12 months predicted subsequent receptive language and ASD outcomes within the high-risk group.

Gestures in Storytelling by Preschool Chinese-Speaking Children With and Without Autism

Previous findings on gestural impairment in autism are inconsistent, while scant evidence came from Chinese-speaking individuals. In the present study, preschool Chinese-speaking children with typical development and with autism were asked to generate stories from a set of wordless Cartoon pictures. Two groups were matched in chronological age and language developmental age. Their speech and gestures were coded. Compared to children with typical development, children with autism produced fewer gestures and showed lower gesture rate. Besides, children with autism produced fewer emblems and fewer supplementary gestures compared to their TD peers. Unlike children with typical development, children with autism tend to produce emblems for reinforcing, rather than supplementing information not conveyed in speech. Results showed the impairments in integrating the cross-modal semantic information in children with autism.

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.

Quantification of speech and synchrony in the conversation of adults with autism spectrum disorder

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder characterized by impairments in social reciprocity and communication together with restricted interest and stereotyped behaviors. The Autism Diagnostic Observation Schedule (ADOS) is considered a ‘gold standard’ instrument for diagnosis of ASD and mainly depends on subjective assessments made by trained clinicians. To develop a quantitative and objective surrogate marker for ASD symptoms, we investigated speech features including F₀, speech rate, speaking time, and turn-taking gaps, extracted from footage recorded during a semi-structured socially interactive situation from ADOS. We calculated not only the statistic values in a whole session of the ADOS activity but also conducted a block analysis, computing the statistical values of the prosodic features in each 8s sliding window. The block analysis identified whether participants changed volume or pitch according to the flow of the conversation. We also measured the synchrony between the participant and the ADOS administrator. Participants with high-functioning ASD showed significantly longer turn-taking gaps and a greater proportion of pause time, less variability and less synchronous changes in blockwise mean of intensity compared with those with typical development (TD) (p<0.05 corrected). In addition, the ASD group had significantly wider distribution than the TD group in the within-participant variability of blockwise mean of log F₀ (p<0.05 corrected). The clinical diagnosis could be discriminated using the speech features with 89% accuracy. The features of turn-taking and pausing were significantly correlated with deficits of ASD in reciprocity (p<0.05 corrected). Additionally, regression analysis provided 1.35 of mean absolute error in the prediction of deficits in reciprocity, to which the synchrony of intensity especially contributed. The findings suggest that considering variance of speech features, interaction and synchrony with conversation partner are critical to characterize atypical features in the conversation of people with ASD.

Atypicalities of Gesture Form and Function in Autistic Adults

While well-represented on clinical measures, co-speech gesture production has never been formally studied in autistic adults. Twenty-one verbally fluent autistic adults and 21 typically developing controls engaged in a controlled conversational task. Group differences were observed in both semantic/pragmatic and motoric features of spontaneously produced co-speech gestures. Autistic adults prioritized different functions of co-speech gesture. Specifically, they used gesture more than controls to facilitate conversational turn-taking, demonstrating a novel nonverbal strategy for regulating conversational dynamics. Autistic adults were more likely to gesture unilaterally than bilaterally, a motoric feature of gesture that was individually associated with autism symptoms. Co-speech gestures may provide a link between nonverbal communication symptoms and known differences in motor performance in autism.

Selection bias on intellectual ability in autism research: a cross-sectional review and meta-analysis

Background

Current global estimates suggest the proportion of the population with autism spectrum disorder (ASD) who have intellectual disability (ID) is approximately 50%. Our objective was to ascertain the existence of selection bias due to under-inclusion of populations with ID across all fields of autism research. A sub-goal was to evaluate inconsistencies in reporting of findings.

Methods

This review covers all original research published in 2016 in autism-specific journals with an impact factor greater than 3. Across 301 included studies, 100,245 participants had ASD. A random effects meta-analysis was used to estimate the proportion of participants without ID. Selection bias was defined as where more than 75% of participants did not have ID.

Results

Meta-analysis estimated 94% of all participants identified as being on the autism spectrum in the studies reviewed did not have ID (95% CI 0.91–0.97). Eight out of ten studies demonstrated selection bias against participants with ID. The reporting of participant characteristics was generally poor: information about participants’ intellectual ability was absent in 38% of studies (n = 114). Where there was selection bias on ID, only 31% of studies mentioned lack of generalisability as a limitation.

Conclusions

We found selection bias against ID throughout all fields of autism research. We recommend transparent reporting about ID and strategies for inclusion for this much marginalised group.

Electronic supplementary material

The online version of this article (10.1186/s13229-019-0260-x) contains supplementary material, which is available to authorized users.

Metaperception in Adolescents With and Without Autism Spectrum Disorder

This study compared how adolescents with and without autism spectrum disorder (ASD) evaluated unfamiliar peers (i.e., perceptions), as well as how adolescents believed they were evaluated by peers (i.e., metaperceptions). The Perceptions and Metaperceptions Questionnaire was designed to quantify perceptions and metaperceptions following a live interaction. For all adolescents, more positive perceptions of the peer were associated with more positive metaperceptions. Adolescents with ASD exhibited more accurate metaperceptions than did typically developing adolescents. More positive perceptions and metaperceptions were associated with higher levels of observed social competence across groups. Findings extend our understanding of typically and atypically developing adolescents' impressions of unfamiliar peers and their ability to discern what peers think of them.

Perspectives on gesture from autism spectrum disorder: Alterations in timing and function

The target article highlights the utility of new technology to study sign language and gesture. Research in special populations – specifically, individuals with autism spectrum disorder, ASD – may further illuminate sign/gesture similarities and differences and lead to a deeper understanding of the mechanisms of growth and change. Even verbally fluent speakers with ASD display distinctive qualities in sign and gesture.

Aberrant Oscillatory Synchrony Is Biased Toward Specific Frequencies and Processing Domains in the Autistic Brain

BACKGROUND

Prevailing theories suggest that autism spectrum disorder (ASD) results from impaired brain communication, causing aberrant synchrony among neuronal populations. However, it remains debated whether synchrony abnormalities are among local or long-range circuits, are circuit specific or are generalized, reflect hypersynchrony or reflect hyposynchrony, and are frequency band-specific or are distributed across the frequency spectrum.

METHODS

To help clarify these unresolved questions, we recorded spontaneous magnetoencephalography data and used a data-driven, whole-brain analysis of frequency-specific interregional synchrony in higher-functioning adolescents and adults, with 17 ASD and 18 control subjects matched on age, IQ, and sex, and equal for motion.

RESULTS

Individuals with ASD showed local hypersynchrony in the theta band (4-7 Hz) in the lateral occipitotemporal cortex. Long-range hyposynchrony was seen in the alpha band (10-13 Hz), which was most prominent in neural circuitry underpinning social processing. The magnitude of this alpha band hyposynchrony was correlated with social symptom severity.

CONCLUSIONS

These results suggest that although ASD is associated with both decreased long-range synchrony and increased posterior local synchrony, with each effect limited to a specific frequency band, impairments in social functioning may be most related to decreased alpha band synchronization between critical nodes of the social processing network.

I tawt i taw a puddy tat: Gestures in canary row narrations by high-functioning youth with autism spectrum disorder

This study examined whether individuals with autism spectrum disorder (ASD) produce co-speech gestures similarly to typically developing (TD) peers. Participants were 20 youth ages 10-18 years with high-functioning ASD and 21 TD controls matched on age, gender, verbal IQ, and handedness. Gestures were elicited using a classic narrative-retelling task, in which participants watched a Tweety and Sylvester cartoon and retold the cartoon to a confederate. Analyses compared gesture rate, type, and viewpoint (character, observer, dual) across groups. Communicative utility of gestures was measured via naïve coder ratings of whether a movement was a gesture, and the clarity of a gesture's meaning. The ASD group produced shorter narratives and fewer total gestures than the TD group. Accounting for narrative length, the ASD group produced fewer gestures per clause than the TD group; however, proportions of gesture types (iconic, deictic, beat, metaphoric, emblems) did not differ. Most notably, the ASD group's gestures were rated as less clearly gestures in terms of timing and well formedness, with lower certainty ratings for gesture meaning. Gesture clarity and gesture meaning scores were related to diagnostic measures of gesture competence in ASD. Findings suggest that although fluent children and adolescents with ASD use the same type of gestures as controls, their gestures are more difficult to understand, which has significant implications for their communicative abilities more broadly. Autism Res 2017, 10: 1353-1363. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.