Autism research : official journal of the International Society for Autism Research最新文献

Despite widespread use of caregiver-child interactions (CCX) to evaluate outcomes in autism interventions, little research has examined the dependability of this measure. This study applied generalizability theory to determine optimal conditions for dependable assessment of child communication and caregiver implementation of communication intervention strategies. Twenty caregiver-child dyads participated in structured interactions across six daily activities on two occasions. Young autistic child communication was measured via tele-health using the Individual Growth and Development Indicators (IGDI) and caregiver implementation using the Naturalistic Developmental Behavioral Intervention Fidelity (NDBI-Fi) scale. Both measures demonstrated strong generalizability when multiple observations were conducted, but significantly lower dependability with single observations. For child communication, three to five activities across two occasions provided optimal dependability (Φ = 0.69-0.82). For caregiver implementation, either four activities on one occasion (Φ = 0.80) or two activities across two occasions (Φ = 0.81) yielded dependable estimates. The greatest sources of error variance were person-by-occasion (54%-59%) and person-by-activity interactions (20%-28%), with all six activities contributing similarly to measurement error. Results indicate that researchers should prioritize collecting multiple CCX observations across different activities and occasions when sampling via telehealth. For optimal feasibility and generalizability, we recommend two observations of 3-4 play-based activities to balance measurement precision with participant burden and intervention relevance.

Autistic individuals exhibit altered perceptual and visuomotor behaviors, potentially due to reduced cortical specialization. The current study focuses on handedness, a robust marker of cerebral specialization, which is less right-biased in autism. Previous studies have typically assessed handedness via questionnaires or simple manual tasks that do not characterize the dynamic, on-going nature of real-life actions. To address this gap, autistic and non-autistic right-handed adults recreated LEGO models from blocks placed on a standardized tabletop, enabling analysis of dynamic, real-world visuomotor behaviors. Autistic participants displayed a lower proportion of right-hand grasps and fewer contralateral movements (i.e., crossing the body midline) with their right hand. Additionally, we observed differences in 3D space utilization, such that autistic participants exhibited a stronger preference for blocks placed closer to their hands. Finally, autistic participants were slower, and their movement trajectories were more idiosyncratic when compared with non-autistic participants. These results reveal reduced hand specialization and profound visuomotor control differences in autism, highlighting potential clinical utility for early, objective autism markers.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition shaped by both genetic and environmental factors. While genetic studies have identified monogenic and polygenic contributions to ASD, growing evidence suggests that environmental exposures can modulate genetic susceptibility. Among these, bisphenol A (BPA), a widely studied endocrine-disrupting chemical, has drawn attention due to its ability to cross the blood-brain barrier and placenta. BPA can influence neurodevelopment through epigenetic modifications, mitochondrial dysfunction, and oxidative stress. Elevated BPA levels have been detected in serum and urine of individuals with ASD, correlating with altered gene expression in brain regions critical for cognition and behavior. Experimental models indicate that BPA exposure disrupts neuronal viability, synaptic connectivity, and neurotransmitter regulation, potentially exacerbating ASD-like phenotypes in genetically predisposed individuals. This review explores the interaction between genetic risk factors and environmental toxins, particularly BPA, in ASD pathogenesis. By integrating findings from epidemiological studies, molecular analyses, and animal models, we highlight the need for further research into gene-environment interactions to refine ASD risk assessment and therapeutic strategies.

Cross-sectional research documents atypical age-related development of white matter in autism spectrum disorder (ASD). However, little is known about the developmental changes in white matter microstructural properties in ASD. This study aims to investigate developmental changes in white matter tract microstructural properties in ASD using a longitudinal follow-up design and normative model analysis, and to examine clinical correlates of these changes. We assessed 75 autistic individuals (aged 15.3 ± 4.2 years) with diffusion spectrum imaging at baseline and 4.7 ± 1.9 years later. To measure the magnitude of deviation from the norm, we calculated z-scores for fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) for each of 76 tracts based on a norm established in 680 typically developing individuals. Callosal fibers connecting the temporal poles, hippocampus, and amygdala in ASD individuals showed higher AD, RD, and MD at both time points. Several tracts showed significantly greater increases in FA z-scores from baseline to follow-up, including the right superior longitudinal fasciculus, precentral thalamic radiation, frontal aslant tract, right corticospinal tracts, left arcuate fasciculus, callosal fibers connecting genu, and bilateral thalamic radiation, implying a pattern of greater deviation from the norm at Time 2 than Time 1. Higher autistic severity or social deficits at baseline were related to greater increasing rates in the diffusion metrics of callosal fibers connecting the precuneus (AD, RD, and MD), corticospinal tract (AD), right geniculate fibers (AD and MD), and right medial lemniscus (AD and MD) from baseline to follow-up. Using the normative model method to analyze longitudinal data on white matter microstructures, our findings support persistent alterations in callosal fibers and developmental alterations of several tracts in ASD, which were associated with baseline autistic severity.

Preliminary studies suggest there are differences in the facial expressions produced by autistic and non-autistic individuals. However, it is unclear what specifically is different, whether such differences remain after controlling for facial morphology and alexithymia, and whether production differences relate to perception differences. Therefore, we (1) comprehensively compared the spatiotemporal and kinematic properties of autistic and non-autistic expressions after controlling these factors, and (2) examined the contribution of production-related variables to emotion perception. We used facial motion capture to record 2448 cued and 2448 spoken expressions of anger, happiness, and sadness from autistic and matched non-autistic adults. Subsequently, we extracted the activation and jerkiness of numerous facial landmarks across time, generating over 265 million datapoints. Participants also completed an emotion recognition task. Autistic participants relied more on the mouth, and less on the eyebrows, to signal anger than their non-autistic peers. For happiness, autistic participants showed a less exaggerated smile that also did not "reach the eyes." For sadness, autistic participants tended to produce a downturned expression by raising their upper lip more than their non-autistic peers. Alexithymia predicted less differentiated angry and happy expressions. For non-autistic individuals, those who produced more precise spoken expressions had greater emotion recognition accuracy. No production-related factors contributed to autistic emotion recognition. This mismatch could explain why autistic people find it difficult to recognize non-autistic expressions, and vice versa; autistic and non-autistic faces may be essentially "speaking a different language" when conveying emotion.

At least one third of autistic people have limited or no speech. Most nonspeaking autistic people are never provided alternatives that would enable the full range of expression that speech allows, significantly limiting their access to educational, social, and employment opportunities. In this commentary, we argue that assisted methods to teach nonspeaking autistic people to type-long dismissed because the assistant could influence the text they produce during training-warrant fresh study. Although these teaching methods developed in practice rather than research, the practice (including the range of support the assistant provides in the motor, sensory, and attentional domains) is aligned with contemporary research about nonspeaking autistic people's strengths and challenges. We suggest that past research showing that influence can occur during training has been over-interpreted to mean that influence always occurs and that nonspeaking autistic people instructed using assisted methods never learn to type independently. In fact, other research shows that influence does not always occur, and there are independent typers who attribute their skill to the range of assistance they received during training. We believe it is time to revisit assisted methods to teach typing in order to understand their potential, as well as their limits, including how successful learners became independent and for whom these methods would be a good match. These efforts have the potential to result in greater access to effective communication and better quality of life for more nonspeaking autistic people.