Hemispheric differences in language processing in autism spectrum disorders: A meta-analysis of neuroimaging studies.

Autism spectrum disorder (ASD) is frequently associated with communicative impairment, regardless of intelligence level or mental age. Impairment of prosodic processing in particular is a common feature of ASD. Despite extensive overlap in neural resources involved in prosody and music processing, music perception seems to be spared in this population. The present study is the first to investigate prosodic phrasing in ASD in both language and music, combining event-related brain potential (ERP) and behavioral methods. We tested phrase boundary processing in language and music in neuro-typical adults and high-functioning individuals with ASD. We targeted an ERP response associated with phrase boundary processing in both language and music – i.e., the Closure Positive Shift (CPS). While a language-CPS was observed in the neuro-typical group, for ASD participants a smaller response failed to reach statistical significance. In music, we found a boundary-onset music-CPS for both groups during pauses between musical phrases. Our results support the view of preserved processing of musical cues in ASD individuals, with a corresponding prosodic impairment. This suggests that, despite the existence of a domain-general processing mechanism (the CPS), key differences in the integration of features of language and music may lead to the prosodic impairment in ASD.

This study investigates the relationship between the perceived stress of parents with a child with (characteristics of) an autism spectrum disorder (ASD) and the degree of ASD characteristics within parents. Data from 222 children (mean age 7.8 years) and their primary caregivers, previously collected as part of the Social Spectrum Study, were analyzed. Linear regression analyses were used to investigate the association between experienced parenting stress and the influence of parents’ own ASD characteristics, taking into account relevant covariates. This study shows that the experienced parenting stress does not show a significant relationship with the ASD characteristics of parents when relevant covariates (such as own psychiatric problems, ASD characteristics of the child and the partner relationship) are added. This study finds indications that parenting stress in parents of children with ASD appears to be more strongly related to their general perceived psychopathology than to their specific ASD characteristics. Further replication is warranted, and we advise research into interventions for parents that possibly prevent (further) stress associated with raising a child with ASD (characteristics).

One of the few replicated functional brain differences between individuals with autism spectrum disorders (ASD) and neurotypical (NT) controls is reduced language lateralization. However, most prior reports relied on comparisons of group-level activation maps or functional markers that had not been validated at the individual-subject level, and/or used tasks that do not isolate language processing from other cognitive processes, complicating interpretation. Furthermore, few prior studies have examined functional responses in other brain networks, as needed to determine the spatial selectivity of the effect. Using functional magnetic resonance imaging (fMRI), we compared language lateralization between 28 adult ASD participants and carefully pairwise-matched controls, with the language regions defined individually using a well-validated language "localizer" task. Across two language comprehension paradigms, ASD participants showed less lateralized responses due to stronger right hemisphere activity. Furthermore, this effect did not stem from a ubiquitous reduction in lateralization of function across the brain: ASD participants did not differ from controls in the lateralization of two other large-scale networks-the Theory of Mind network and the Multiple Demand network. Finally, in an exploratory study, we tested whether reduced language lateralization may also be present in NT individuals with high autism-like traits. Indeed, autistic trait load in a large set of NT participants (n = 189) was associated with less lateralized language responses. These results suggest that reduced language lateralization is robustly associated with autism and, to some extent, with autism-like traits in the general population, and this lateralization reduction appears to be restricted to the language system. LAY SUMMARY: How do brains of individuals with autism spectrum disorders (ASD) differ from those of neurotypical (NT) controls? One of the most consistently reported differences is the reduction of lateralization during language processing in individuals with ASD. However, most prior studies have used methods that made this finding difficult to interpret, and perhaps even artifactual. Using robust individual-level markers of lateralization, we found that indeed, ASD individuals show reduced lateralization for language due to stronger right-hemisphere activity. We further show that this reduction is not due to a general reduction of lateralization of function across the brain. Finally, we show that greater autistic trait load is associated with less lateralized language responses in the NT population. These results suggest that reduced language lateralization is robustly associated with autism and, to some extent, with autism-like traits in the general population. Autism Res 2020, 13: 1746-1761. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

BackgroundIndividuals with Autism Spectrum Disorder (ASD) consistently exhibit difficulties in comprehending figurative language. While prior neuroimaging studies have identified discrepancies in brain activation between ASD individuals and neurotypical controls (NCs) during such tasks, the specific and consistent neural patterns underlying these deficits remain unclear.MethodsWe conducted an activation likelihood estimation (ALE) meta-analysis to identify consistent brain activation patterns associated with figurative language comprehension in ASD. A systematic literature search was performed across five databases (PubMed, Embase, Web of Science, CNKI, Wanfang) up to January 31, 2025. Six functional magnetic resonance imaging (fMRI) studies, comprising 95 individuals with ASD and 98 NCs, met the inclusion criteria.ResultsThe analysis revealed that during figurative language comprehension, both ASD and NCs consistently activated a core network involving the bilateral superior temporal gyrus (STG), transverse temporal gyrus, and right insula. A conjunction analysis confirmed the stability of these shared regions. Crucially, the meta-analysis of group differences (NCs > ASD) identified a significant cluster of hypoactivation in the ASD group within the left STG and middle temporal gyrus (MTG). No significant hyperactivation was found in the ASD group compared to NCs.ConclusionThis meta-analysis demonstrates that while individuals with ASD recruit typical language networks during figurative language comprehension, they exhibit a consistent pattern of reduced neural recruitment in the left STG and MTG. This hypoactivation may reflect a dual deficit encompassing reduced efficiency in semantic access/integration and impaired socio-linguistic integration, providing a neurobiological substrate for the pragmatic language difficulties characteristic of ASD.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD42023467185, CRD42023467185.

The aim of this study was to examine the relationship between emotion dysregulation and the core features of Autism Spectrum Disorder (ASD), which include social/communication deficits, restricted/repetitive behaviors, and sensory abnormalities. An 18-item Emotion Dysregulation Index was developed on the basis of expert ratings of the Child Behavior Checklist. Compared to typically developing controls, children and adolescents with ASD showed more emotion dysregulation and had significantly greater symptom severity on all scales. Within ASD participants, emotion dysregulation was related to all core features of the disorder, but the strongest association was with repetitive behaviors. These findings may facilitate the development of more effective therapeutic strategies targeting emotion dysregulation in order to optimize long-term outcomes for individuals with ASD.

Autism spectrum disorder (ASD) is a neurodevelopmental disability with global implication. Altered brain connectivity in the language network has frequently been reported in ASD patients using task-based functional magnetic resonance imaging (fMRI) compared to typically developing (TD) participants. Most of these studies have focused on a specific age group or mixed age groups with ASD. In the current study, we investigated age-related changes in functional connectivity related measure, degree centrality (DC), in the language network across three age groups with ASD (113 children, 113 adolescents and 103 adults) using resting-state fMRI data collected from the autism brain imaging data exchange repository. We identified regions with significant group-wise differences between ASD and TD groups for three age cohorts using DC based on graph theory. We found that both children and adolescents with ASD showed decreased DC in Broca’s area compared to age-matched TD groups. Adults with ASD showed decreased DC in Wernicke’s area compared to TD adults. We also observed increased DC in the left inferior parietal lobule (IPL) and left middle temporal gyrus (MTG) for children with ASD compared to TD children and for adults with ASD compared to TD adults, respectively. Overall, functional differences occurred in key language processing regions such as the left inferior frontal gyrus (IFG) and superior temporal gyrus (STG) related to language production and comprehension across three age cohorts. We explored correlations between DC values of our findings with autism diagnostic observation schedule (ADOS) scores related to severity of ASD symptoms in the ASD group. We found that DC values of the left IFG demonstrated negative correlations with ADOS scores in children and adolescents with ASD. The left STG showed significant negative correlations with ADOS scores in adults with ASD. These results might shed light on the language network regions that should be further explored for prognosis, diagnosis, and monitoring of ASD in three age groups.

Atypical lexicosemantic function of extrastriate cortex in autism spectrum disorder: Evidence from functional and effective connectivity

An integrative multi-omics approach identifies microbiome alterations linked to pathological and behavioral features in autism spectrum disorder

Autism spectrum disorder (ASD) is a lifelong heterogeneous neurodevelopmental condition that is associated with differences in brain anatomy and connectivity. Yet, the molecular and cellular mechanisms that underpin the atypical developmental of the brain in ASD remain poorly understood. Here, we review the findings of in vivo neuroimaging studies examining the time course of atypical brain development in ASD and relate the different neurodevelopmental stages that are atypical in ASD to the known neurobiological mechanisms that drive the maturation of the typically developing brain. In particular, we focus on the notion of 'early brain overgrowth' in ASD, which may lead to differences in the formation of the brain's micro- and macro-circuitry. Moreover, we attempt to link the in vivo reports describing differences in brain anatomy and connectivity on the macroscopic level to the increasing number of post-mortem studies examining the neural architecture of the brain in ASD on the microscopic level. In addition, we discuss future directions and outstanding questions in this particular field of research and highlight the need for establishing the link between micro- and macro-pathology in the same set of individuals with ASD based on advances in genetic, molecular and imaging techniques. In combination, these may proof to be invaluable for patient stratification and the development of novel pharmacotherapies in the future.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and repetitive behaviors. Children with ASD are statistically more likely to experience early adversity; however, little is known about the types of early adversity that place these children at risk, the role of parenting as a protective factor, and how this early life stress impacts cognitive outcomes. We assessed early adversity in 302 children (ASD=98) aged 6-16 years old, using parent-based report. To identify protective factors, we assessed parenting styles using parent surveys. Executive functions were assessed in the children using the WISC-V. Children with ASD had an increased incidence of familial stressors compared to the typically developing (TD) group. Positive parenting was associated with a significant decrease in the incidence of familial adverse events for both children with ASD and TD children. Examining the relationship between adversity and cognitive outcomes, in young children (6-11 years) with ASD, environmental stressors were associated with cognitive impairments. Findings suggest children with ASD may be at higher risk for familial adversity than their TD peers. However, all children benefit from positive parenting styles, which may mitigate the adverse effects of family-based early life stress. LAY SUMMARY: Some key features of Autism Spectrum Disorder (ASD) include difficulties with communication and social impairments. This means that children with ASD may be more likely to experience early adversity (stressful social interactions which take place during childhood) than children without ASD. Research in typically developing (TD) children has shown that experiencing more stressful events in childhood can cause changes in the brain, which can potentially impact the child's memory, reasoning, and decision-making skills later in life. However, there is evidence to suggest that having a nurturing relationship with a parent can offset some of the negative impacts of childhood adversity. In our study, we found that children with ASD are more likely to experience family-related stress compared to TD children. Having a positive relationship with a parent, however, was linked to experiencing this type of stress less often for all children, regardless of whether they were diagnosed with ASD. We also found that stressors related to environmental factors like financial instability were associated with lower cognitive abilities in children with ASD under 12 years of age. Understanding how these factors interact and differ in children with ASD can help to build stronger families and help children with ASD to thrive throughout their development.

Bone microarchitecture in adolescent boys with autism spectrum disorder

In his first description of Autism Spectrum Disorders (ASD), Kanner emphasized emotional impairments by characterizing children with ASD as indifferent to other people, self-absorbed, emotionally cold, distanced, and retracted. Thereafter, emotional impairments became regarded as part of the social impairments of ASD, and research mostly focused on understanding how individuals with ASD recognize visual expressions of emotions from faces and body postures. However, it still remains unclear how emotions are processed outside of the visual domain. This systematic review aims to fill this gap by focusing on impairments of emotional language processing in ASD. We systematically searched PubMed for papers published between 1990 and 2013 using standardized search terms. Studies show that people with ASD are able to correctly classify emotional language stimuli as emotionally positive or negative. However, processing of emotional language stimuli in ASD is associated with atypical patterns of attention and memory performance, as well as abnormal physiological and neural activity. Particularly, younger children with ASD have difficulties in acquiring and developing emotional concepts, and avoid using these in discourse. These emotional language impairments were not consistently associated with age, IQ, or level of development of language skills. We discuss how emotional language impairments fit with existing cognitive theories of ASD, such as central coherence, executive dysfunction, and weak Theory of Mind. We conclude that emotional impairments in ASD may be broader than just a mere consequence of social impairments, and should receive more attention in future research.

Inflexibility in Autism Spectrum Disorder: Need for certainty and atypical emotion processing share the blame

The brain represents the state of the world around us based upon a stream of ambiguous sensory data. This requires the integration of different sources of information, including information received from different sense modalities, and information drawn from past experience. Bayesian theories of perception provide an approach to characterising how systematic differences in the probabilistic integration of information in the brain may underlie the differences that occur between individuals in their perceptual experience. The present thesis explores how perceptual, motor and social aspects of autism spectrum disorder (ASD) may emerge from variation in the neurocognitive processes described by Bayesian theories. A focus is on the predictive processing model of brain function, which links Bayesian theories of perception to neural mechanisms. The thesis includes empirical studies that examine perceptual, sensorimotor and cognitive aspects of ASD. ASD and nonclinical autistic traits are first examined in the context of body perception; concerning, specifically, how the brain represents the state of the limbs based on visual, tactile and proprioceptive information, and how this sensory information is integrated with prior expectations regarding the body. These processes are investigated using a multisensory perceptual illusion: the rubber hand illusion. ASD is associated with a largely typical perceptual experience of this illusion, indicating intact multisensory integration in the context of body representation. A reduced influence of the illusion on motor function, however, supports a difference in ASD in the integration of expectations for limb position (influenced by the illusion) with conflicting sensory (proprioceptive) signals. The integration of incoming information with existing expectations about the environment is also examined in the context of statistical learning. A computerised task is developed to assess the integration of iterative feedback with prior information as participants predict the location of a noisy set of visual markers. The hypothesis tested is that features of ASD are associated with a persistently higher weighting of incoming information in driving inference, at the expense of expectations developed from recent experience; in this more cognitive context, these data provide evidence against this hypothesis, suggesting that a more context-dependent atypicality in information processing in ASD is more likely than that initially hypothesised. The thesis also develops theoretical and philosophically-relevant treatments of how the symptoms of ASD may emerge from differences in brain function characterised within a Bayesian framework. This includes drawing on recent theoretical developments regarding the role of volatility processing and action in maintaining optimal inference on the environment. In addition, models of Bayesian inference in the brain can be extended to the social domain. For instance, the process of representing the mental states of other people (i.e., theory of mind) can be cast in terms of implicit inference on the external causes of sensory signals. In light of these expanded models of predictive processing, the differences in information processing hypothesised to occur in ASD have implications not just for perception, but also for motor behaviours, social cognition and social interaction. The overall view that emerges is that diverse aspects of ASD may be captured in terms of how incoming sensory signals are integrated, in a probabilistic manner, with the brain’s hierarchical and multimodal model of its environment. A promising direction for this field is in developing this idea in the context of action (i.e., active inference) and more recent models of how the brain estimates the optimal weighting of sensory information. This area of research has the potential to provide a nuanced perspective on the neurocognitive basis of ASD and the relationship between sensory mechanisms and autistic behaviours.

Children with autism spectrum disorders (ASD) present deficits in regulation of their emotions which have a great impact on their mental health and well-being. There are several studies showing the connection between executive functions deficits and emotion dysregulation in the context of an ASD diagnosis. Our study aims to investigate which among the executive functions can predict the emotional dysregulation in children with ASD, if there is an association between the ASD specific characteristics and their ability to regulate their emotions and to identify if there are possible mediators of this relationship. To reach our objective, we enrolled 60 children with ASD (mean age 8.5 years) whose parents completed standardised measurements for executive functions, emotional dysregulation, and ASD characteristics. We found a positive association between ASD characteristics’ severity and emotional dysregulation, as well as some significant predictors among specific executive functions and emotional dysregulation. Moreover, executive functioning mediates the relationship between the ASD characteristics and emotion regulation. Our research provides a better understanding of the relationship between ASD characteristics, executive functions, and emotion regulation.