Level of Attention to Motherese Speech as an Early Marker of Autism Spectrum Disorder

Abstract

ImportanceCaregivers have long captured the attention of their infants by speaking in motherese, a playful speech style characterized by heightened affect. Reduced attention to motherese in toddlers with autism spectrum disorder (ASD) may be a contributor to downstream language and social challenges and could be diagnostically revealing.ObjectiveTo investigate whether attention toward motherese speech can be used as a diagnostic classifier of ASD and is associated with language and social ability.Design, Setting, and ParticipantsThis diagnostic study included toddlers aged 12 to 48 months, spanning ASD and non-ASD diagnostic groups, at a research center. Data were collected from February 2018 to April 2021 and analyzed from April 2021 to March 2022.ExposuresGaze-contingent eye-tracking test.Main Outcomes and MeasuresUsing gaze-contingent eye tracking wherein the location of a toddler’s fixation triggered a specific movie file, toddlers participated in 1 or more 1-minute eye-tracking tests designed to quantify attention to motherese speech, including motherese vs traffic (ie, noisy vehicles on a highway) and motherese vs techno (ie, abstract shapes with music). Toddlers were also diagnostically and psychometrically evaluated by psychologists. Levels of fixation within motherese and nonmotherese movies and mean number of saccades per second were calculated. Receiver operating characteristic (ROC) curves were used to evaluate optimal fixation cutoff values and associated sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Within the ASD group, toddlers were stratified based on low, middle, or high levels of interest in motherese speech, and associations with social and language abilities were examined.ResultsA total of 653 toddlers were included (mean [SD] age, 26.45 [8.37] months; 480 males [73.51%]). Unlike toddlers without ASD, who almost uniformly attended to motherese speech with a median level of 82.25% and 80.75% across the 2 tests, among toddlers with ASD, there was a wide range, spanning 0% to 100%. Both the traffic and techno paradigms were effective diagnostic classifiers, with large between-group effect sizes (eg, ASD vs typical development: Cohen d, 1.0 in the techno paradigm). Across both paradigms, a cutoff value of 30% or less fixation on motherese resulted in an area under the ROC curve (AUC) of 0.733 (95% CI, 0.693-0.773) and 0.761 (95% CI, 0.717-0.804), respectively; specificity of 98% (95% CI, 95%-99%) and 96% (95% CI, 92%-98%), respectively; and PPV of 94% (95% CI, 86%-98%). Reflective of heterogeneity and expected subtypes in ASD, sensitivity was lower at 18% (95% CI, 14%-22%) and 29% (95% CI, 24%-34%), respectively. Combining metrics increased the AUC to 0.841 (95% CI, 0.805-0.877). Toddlers with ASD who showed the lowest levels of attention to motherese speech had weaker social and language abilities.Conclusions and RelevanceIn this diagnostic study, a subset of toddlers showed low levels of attention toward motherese speech. When a cutoff level of 30% or less fixation on motherese speech was used, toddlers in this range were diagnostically classified as having ASD with high accuracy. Insight into which toddlers show unusually low levels of attention to motherese may be beneficial not only for early ASD diagnosis and prognosis but also as a possible therapeutic target.

Editorial: Horizons of autism spectrum disorder and attention deficit hyperactivity disorder in clinical practice

“…Early identification and screening for ASD are crucial for improving the prognosis of autistic children through evidence-based early intervention ( 3 ). The early clinical symptoms of ASD can be typically manifested as dysfunctions in eye contact, pointing by forefinger, response to name calling, communication, and inappropriate object use or abnormal sensory or perceptual in toddlers.…”

When Can Causal-Analytic Methods Inform Design-Based Research?

“…The work of Pierce et al characterizes the associations between adverse events experienced in childhood and disrupted social-psychological development and diminished opportunities for educational flourishing. In this large-scale, longitudinal, retrospective observational cohort study, Pierce et al use data available from Swedish registries to evaluate evidence for the (causally interpretable) adjusted association of adverse events experienced in childhood with the development of anxiety and depression (ie, common mental disorders) and average performance in school in a cohort of more than 160 000 Swedish children followed up from birth until their twenty-first birthday.…”

“…The work of Pierce et al characterizes the associations between adverse events experienced in childhood and disrupted social-psychological development and diminished opportunities for educational flourishing. In this large-scale, longitudinal, retrospective observational cohort study, Pierce et al use data available from Swedish registries to evaluate evidence for the (causally interpretable) adjusted association of adverse events experienced in childhood with the development of anxiety and depression (ie, common mental disorders) and average performance in school in a cohort of more than 160 000 Swedish children followed up from birth until their twenty-first birthday. By using the g-computation framework, a suite of statistical methods for the analysis of observational study data, to estimate associations while adjusting for possibly complex time-varying confounding, the authors uncover significant evidence of a protective association between preventing adverse events and the prevalence of common mental disorders (a reduction of 2.6%, from an observed 10.2% to an expected 7.6%) as well as a positive association with educational attainment (an expected increase of 0.149 SDs for grades).…”

“…Two key issues that arise in the work of Pierce et al merit further discussion: the use of analytic methods to evaluate the possible effects of hypothetical interventions that are not themselves well defined, and the promises and pitfalls of research findings derived from observational studies relative to those extracted from randomized clinical trials. In their analysis of the Swedish registry data, these authors consider how the associations—or, under well-studied assumptions, the causal effects—of “preventing childhood adversity could provide notable improvements in the rates of common mental disorders.” While informative, an important next step in any impactful analysis would be to formulate a set of well-specified interventions that could be carried out in practice and frame an analysis in terms of such well-defined counterfactual contrasts.…”

“…Two key issues that arise in the work of Pierce et al merit further discussion: the use of analytic methods to evaluate the possible effects of hypothetical interventions that are not themselves well defined, and the promises and pitfalls of research findings derived from observational studies relative to those extracted from randomized clinical trials. In their analysis of the Swedish registry data, these authors consider how the associations—or, under well-studied assumptions, the causal effects—of “preventing childhood adversity could provide notable improvements in the rates of common mental disorders.” While informative, an important next step in any impactful analysis would be to formulate a set of well-specified interventions that could be carried out in practice and frame an analysis in terms of such well-defined counterfactual contrasts. For example, the authors found that preventing parental separation provided for the greatest improvement, yet such a vague intervention constitutes not only a violation of the consistency rule in causal inference but also fails to suggest a plausible intervention (eg, marriage counseling to prevent parental separation), which may yet fail in practice; thus, one is left to interpret the substantive results of this hypothetical analysis in terms of implausible interventions (eg, marriage counseling that can never fail).…”