Mechanisms by which Early Eye Gaze to the Mouth During Multisensory Speech Influences Expressive Communication Development in Infant Siblings of Children with and without Autism

Sensitivity to temporal synchrony and selective attention in audiovisual speech in infants at elevated likelihood for autism: A preliminary longitudinal study

Autism Spectrum Disorder is a highly heritable condition characterized by sociocommunicative difficulties, frequently entailing language atypicalities that extend to infants with a familial history of autism. The developmental mechanisms underlying these difficulties remain unknown. Detecting temporal synchrony between the lip movements and the auditory speech of a talking face and selectively attending to the mouth support typical early language acquisition. This preliminary eye-tracking study investigated whether these two fundamental mechanisms atypically function in infant siblings. We longitudinally tracked the trajectories of infants at elevated and low-likelihood for autism in these two abilities at 4, 8, and 12 months (n = 29). We presented two talking faces (synchronous and asynchronous) while recording infants' gaze to the talker's eyes and mouth. We found that infants detected temporal asynchronies in talking faces at 12 months regardless of group. However, compared to their typically developing peers, infants with an elevated likelihood of autism showed reduced attention to the mouth at the end of the first year and no variations in their interest to this area across time. Our findings provide preliminary evidence on a potentially atypical trajectory of reduced mouth-looking in audiovisual speech during the first year in infant siblings, with potential cascading consequences for language development, thus contributing to domain-general accounts of emerging autism.

Longitudinal Relations Between Early Sensory Responsiveness and Later Communication in Infants with Autistic and Non-autistic Siblings

Early differences in sensory responsiveness may contribute to difficulties with communication among autistic children; however, this theory has not been longitudinally assessed in infants at increased familial versus general population-level likelihood for autism (Sibs-autism vs. Sibs-NA) using a comprehensive battery of sensory responsiveness and communication. In a sample of 40 infants (20 Sibs-autism, of whom six were later diagnosed with autism; 20 Sibs-NA), we tested (a) associations between sensory responsiveness at 12-18 months and communication 9 months later and (b) evaluated whether such associations were moderated by sibling group, autism diagnosis, or age. We found negative zero-order correlations between sensory responsiveness (i.e., caregiver reported hyperresponsiveness and hyporesponsiveness; an observational measure of hyperresponsiveness) and later communication. Additionally, caregiver reported sensory seeking was negatively associated with later expressive communication only in Sibs-NA. Limitations include our relatively small sample size of infants diagnosed with autism. Implications for future research are discussed.

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.

A Randomized Controlled Trial for Audiovisual Multisensory Perception in Autistic Youth

Differences in audiovisual integration are commonly observed in autism. Temporal binding windows (TBWs) of audiovisual speech can be trained (i.e., narrowed) in non-autistic adults; this study evaluated a computer-based perceptual training in autistic youth and assessed whether treatment outcomes varied according to individual characteristics. Thirty autistic youth aged 8-21 were randomly assigned to a brief perceptual training (n = 15) or a control condition (n = 15). At post-test, the perceptual training group did not differ, on average, on TBWs for trained and untrained stimuli and perception of the McGurk illusion compared to the control group. The training benefited youth with higher language and nonverbal IQ scores; the training caused widened TBWs in youth with co-occurring cognitive and language impairments.

The Processing of Audiovisual Speech Is Linked with Vocabulary in Autistic and Nonautistic Children: An ERP Study

Explaining individual differences in vocabulary in autism is critical, as understanding and using words to communicate are key predictors of long-term outcomes for autistic individuals. Differences in audiovisual speech processing may explain variability in vocabulary in autism. The efficiency of audiovisual speech processing can be indexed via amplitude suppression, wherein the amplitude of the event-related potential (ERP) is reduced at the P2 component in response to audiovisual speech compared to auditory-only speech. This study used electroencephalography (EEG) to measure P2 amplitudes in response to auditory-only and audiovisual speech and norm-referenced, standardized assessments to measure vocabulary in 25 autistic and 25 nonautistic children to determine whether amplitude suppression (a) differs or (b) explains variability in vocabulary in autistic and nonautistic children. A series of regression analyses evaluated associations between amplitude suppression and vocabulary scores. Both groups demonstrated P2 amplitude suppression, on average, in response to audiovisual speech relative to auditory-only speech. Between-group differences in mean amplitude suppression were nonsignificant. Individual differences in amplitude suppression were positively associated with expressive vocabulary through receptive vocabulary, as evidenced by a significant indirect effect observed across groups. The results suggest that efficiency of audiovisual speech processing may explain variance in vocabulary in autism.

Associations Between Caregiver Stress and Language Outcomes in Infants With Autistic and Non-Autistic Siblings: An Exploratory Study

PURPOSE

Caregivers of autistic children present with high stress levels, which have been associated with poorer child outcomes in several domains, including language development. However, prior to this study, it was unknown whether elevated caregiver stress was associated with language development in infant siblings of autistic children (Sibs-autism), who are at increased likelihood of receiving a future diagnosis of autism and/or language impairment compared to infant siblings of non-autistic children. This study explored the degree to which, as well as the mechanisms by which, caregiver stress was linked with later language outcomes of Sibs-autism and infant siblings of non-autistic children (Sibs-NA).

METHOD

Participants were 50 infants (28 Sibs-autism; 22 Sibs-NA) aged 12-18 months at the first time point in this study (Time 1). Infants were seen again 9 months later, at 21-27 months of age (Time 2). Caregiver stress was measured via a validated self-report measure at Time 1. Caregiver language input, the putative mechanism by which caregiver stress may influence later language outcomes, was collected via two daylong recordings from digital recording (Language ENvironment Analysis) devices worn by the child at this same time point. Child language outcomes were measured via standardized and caregiver report measures at Time 2.

RESULTS

Several models testing hypothesized indirect effects of caregiver stress on later child language outcomes through caregiver language input were statistically significant. Specifically, significant indirect effects suggest that (a) caregivers with increased stress tend to speak less to their infants, and (b) this reduced language input tends to covary with reduced child language outcomes later in life for Sibs-autism and Sibs-NA.

CONCLUSIONS

This study provides new insights into links between caregiver stress, caregiver language input, and language outcomes in Sibs-autism and Sibs-NA. Further work is necessary to understand how to best support caregivers and optimize the language learning environments for infants.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21714368.

Infant looking preferences towards dynamic faces: A systematic review

Although the pattern of visual attention towards the region of the eyes is now well-established for infants at an early stage of development, less is known about the extent to which the mouth attracts an infant's attention. Even less is known about the extent to which these specific looking behaviours towards different regions of the talking face (i.e., the eyes or the mouth) may impact on or account for aspects of language development. The aim of the present systematic review is to synthesize and analyse (i) which factors might determine different looking patterns in infants during audio-visual tasks using dynamic faces and (ii) how these patterns have been studied in relation to aspects of the baby's development. Four bibliographic databases were explored, and the records were selected following specified inclusion criteria. The search led to the identification of 19 papers (October 2021). Some studies have tried to clarify the role played by audio-visual support in speech perception and early production based on directly related factors such as the age or language background of the participants, while others have tested the child's competence in terms of linguistic or social skills. Several hypotheses have been advanced to explain the selective attention phenomenon. The results of the selected studies have led to different lines of interpretation. Some suggestions for future research are outlined.