Early behavioral features associated with autism spectrum disorder (ASD) are frequently examined within separate motor, sensory, and social domains rather than as interacting components of a developing neurobiological system. In this article, we present a hypothesis-driven conceptual framework proposing that variation in developmental timing and coordination across neural, motor, and interpersonal systems may contribute to differences in early social developmental trajectories. Drawing on evidence from fetal, infant, and early childhood development, we consider how hemispheric specialization, interhemispheric coordination, oscillatory synchronization, corticalization of motor control, and dyadic interaction timing may jointly influence the emergence of motor organization and social engagement. From this perspective, persistent primitive reflex expression, atypical motor asymmetry, increased motor variability, and differences in dyadic synchrony are discussed as candidate developmental indicators that may reflect broader variation in neural timing and coordination. Within this framework, we further consider how genetic, neurobiological, and environmental factors associated with ASD risk may converge on developmental timing processes expressed through neural communication, motor regulation, and social interaction. Rather than proposing a deterministic causal sequence, the present account examines how variation in motor-social interaction may influence opportunities for social learning through recurrent cycles of action, perception, prediction, and caregiver feedback. We advance a set of empirically testable developmental hypotheses linking neural timing measures, motor organization indices, reflex integration profiles, and dyadic interaction metrics within prospective longitudinal research designs. Specifically, the framework predicts that variation in early neural timing and coordination will be associated with differences in motor organization and motor-social coupling, which may in turn relate to later social developmental outcomes. By emphasizing developmental timing, coordination, and reciprocal interaction across neural, motor, and interpersonal systems, this conceptual framework is intended not as a causal account of ASD, but a hypothesis-generating developmental model that organizes existing evidence while generating explicit, empirically testable predictions regarding relationships among neural timing, motor organization, and early social interaction.

Visual-evoked potential plasticity (VEPP) is a noninvasive form of cortical neuroplasticity elicited by repeated presentation of high-contrast visual stimuli. In rodent models, stimulus-specific response potentiation (SSRP) effects accumulate across days; however, it remains unclear whether repeated exposure across days influences the magnitude or specificity of potentiation in humans. In addition, visual cortical plasticity may not be determined by experience alone: voluntary attentional deployment selects which inputs are prioritized, and may thereby determine how much a given amount of sensory experience alters cortical excitability. Here, we examined whether covert spatial attention and repeated exposure across days modulate VEPP strength using high-density electroencephalography (EEG) in neurotypical adults. An established VEP modulation paradigm was modified to use steady-state visual evoked potential (SSVEP) stimuli, which we refer to as steady-state visual response potentiation (SSVRP). Pre- and post-induction amplitudes were measured using frequency-tagged (6 and 7.5 Hz) bilateral hemifield contrast-sweep checkerboard steady-state visual evoked potentials (SSVEPs). A 10-min, high-contrast, 2 Hz sign-reversing induction stimulus was presented exclusively to the left hemifield, with the right serving as control. Across two experimental sessions, participants attended either toward or away from the potentiated hemifield during induction. Notably, attention enhanced SSVRP in the first session day but not the second session day, reflecting a significant interaction between attention and session day. Potentiation was significantly greater on the second session day, independent of attention condition. Of note, potentiation occurred in both hemifields despite the potentiating stimulus only being presented in the left hemifield. Our results tentatively suggest that spatial attention and experience jointly modulate human visual cortical plasticity.

Chronotype and sleep problems are common in autism spectrum disorder (ASD), but their genetic relationship remains uncertain. We integrated published cross-trait LD score regression (LDSC), brain eQTL-based summary-data-based Mendelian randomization (SMR), SNP-based two-sample MR, two-step mediation MR, secondary parallel SMR, and Bayesian colocalization using UK Biobank chronotype GWASs, the iPSYCH/Psychiatric Genomics Consortium ASD GWAS, and GTEx v8 brain eQTLs. The published LDSC estimate was negative for morningness-coded chronotype and ASD (rG = -0.199). Primary ASD-outcome SMR identified 50 gene-tissue pairs representing 24 genes at the exploratory multi-SNP PSMR < 0.001 threshold; none met Bonferroni significance. Fifteen candidates occurred in the LD-rich 17q21.31 inversion and are not independent gene discoveries. Secondary eveningness-outcome SMR tested all 24 candidates in matched tissues; 22 had PSMR < 0.05, but GTEx reuse made this descriptive. At 17q21.31, the prespecified p12 = 1 × 10⁻⁵ favored distinct variants (PP.H3 = 0.785) over one shared variant (PP.H4 = 0.126). H3 dominance strengthened at p12 = 1 × 10⁻⁶ and reversed only at the permissive p12 = 1 × 10⁻⁴, equal to p1 and p2. Eveningness-oriented IVW MR was positive (β = 0.270, P = 0.008), whereas robust estimators were attenuated; no mediation was detected through sleep duration or insomnia complaints. These analyses prioritize exploratory regional associations without proving shared causality or mechanism.

The etiology of pediatric autism spectrum disorder (ASD) has been increasingly linked to alterations in the gut-brain axis, highlighting the intricate bidirectional communication between gut microbiota and central nervous system. The molecular mechanisms of this communication are poorly understood. Here we investigated whether ASD-associated gut microbiota could exhibit altered inflammatory molecular outputs by integrating chemistry-driven profiling of fecal lipopolysaccharides (LPS), functional bacterial proteomics, and neuroimmune cellular assays. Structural analyses revealed that LPS from non-autistic healthy donors (NASD) displayed highly conserved carbohydrate and lipid A signatures dominated by hypo-acylated mono-phosphorylated species typically associated with immunomodulatory Bacteroides-derived LPS. In contrast, LPS from ASD children exhibited increased structural heterogeneity. These molecular alterations were functionally reflected in human HMC3 microglial cells, where ASD-derived fecal LPS induced stronger IL-6 and IL-8 release compared with NASD-derived LPS, indicating enhanced neuroinflammatory potential. Functional proteomic profiling disclosed broadly comparable microbial compositions but marked metabolic divergence. These findings suggest that gut microbiota in ASD children are associated with a functionally heterogeneous microbial ecosystem characterized by altered immunostimulatory molecular outputs despite the absence of massive taxonomic shifts, with potential relevance for neuroimmune dysregulation.

Rejection Sensitivity Dysphoria (RSD) is an intense, deep rooted feeling of embarrassment, anxiety and failure that can be all-consuming and deeply impactful. RSD is common in neurodivergent learners, particularly those with autism and ADHD. It is essential that medical educators' feedback strategies recognize and support those with RSD, so that distress may be reduced and these learners can rightfully flourish in medical training. Moreover, by adopting a relational and inclusive approach to feedback, other learners will also benefit, particularly those who are anxious, highly self-critical or perfectionist. This paper supports educators to understand and recognize RSD before discussing approaches to adapting feedback. Addressing a mismatch between learner needs and the feedback process or environment is key. Utilizing alternative feedback models, prioritizing rapport, providing written feedback and supporting learners to manage their emotional dysregulation are practical strategies.

Precise and up-to-date information about animal location and identity allows us to better quantify individual behaviors in studies of neural activity, cognition, and animal health. In socially housed laboratory animals, identification is usually defined by observation or invasive markers, making the data collection time-consuming, variable across experimenters, and disruptive to animals. We established an automatic pipeline for real-time identification of common marmosets in captivity using a close-view camera. It uses the supervised deep-learning YOLOv8 model to localize individuals, detect faces, and classify identities. Moreover, we use recognition of uniquely color-coded collar beads to improve detection accuracy among visually similar individuals. Across adult and juvenile marmosets, our system automatically identifies marmosets with >82.9% precision and >91.5% recall, achieving human-level performance. This pipeline is designed to be easy to use and generalizable across non-human primate species, ages, and recording hardware, providing rapid and automatic identity recognition from real-time video.

Depression remains underdiagnosed in non- and minimally speaking (NMS) autistic adults, despite caregiver concerns suggesting high rates of mood-related difficulties, as such this study evaluates the validity, reliability, and feasibility of three established caregiver-report depression measures (Anxiety, Depression, and Mood Scale-ADAMS; Glasgow Depression Scale-Caregiver Supplement-GDS-CS; Mood, Interest, and Pleasure Questionnaire-MIPQ) with 160 caregivers of NMS autistic adults. Participants completed surveys, and a subset engaged in cognitive interviews to assess content validity and usability. Psychometric analyses included confirmatory factor analyses, internal consistency estimation, and exploratory cut-off scores based on parent-reported concern about depression. Results indicated that the GDS-CS had the strongest support, showing acceptable model fit, fair reliability, and high caregiver acceptability. The ADAMS also demonstrated strong psychometric properties and feasibility, with the added benefit of capturing related symptoms such as anxiety. The MIPQ, while designed for individuals with limited language, showed poor model fit and lower caregiver usability. Findings support the use of the GDS-CS and ADAMS as promising tools for screening depression in NMS autistic adults and highlight the need for further validation and tailored mental health assessment approaches for this underserved population.Lay AbstractSome autistic people do not use speech to communicate, even when they become adults. These individuals are called minimally speaking (or nonspeaking; NMS). Many parents think their NMS autistic adult children may be depressed, but few have a diagnosis from a doctor. One reason for this is that most ways doctors check for depression ask about feelings using spoken words. This does not work well for people who do not speak. This study asked 160 parents of minimally speaking autistic adults to fill out three surveys that may help identify depression. The surveys were the ADAMS, the GDS-CS, and the MIPQ. The parents answered questions about how their adult children behave, how often certain things happen, and whether they think their child is depressed. Some parents also talked in interviews about how easy or hard the surveys were to understand and complete. The results showed that two of the surveys, the ADAMS and the GDS-CS, worked pretty well and were quick to fill out. Parents said the GDS-CS was the easiest to understand. The third survey, the MIPQ, was harder for parents to use and did not work as well. This study shows that it is possible to screen for depression in autistic adults who do not speak by asking caregivers the right kinds of questions. It also shows that more research is needed to make sure these tools work for everyone. Doctors and caregivers can use these tools to find people who may be feeling depressed and need more help. This is an important step toward making sure all autistic adults, including those who don't speak, get the mental health care they need.