Cognitive set shifting deficits and their relationship to repetitive behaviors in autism spectrum disorder

Multilingualism impacts children's executive function and core autism symptoms

Autism spectrum disorder (ASD) is associated with marked heterogeneity in executive function (EF) abilities. EF components including inhibition and shifting are related to ASD core symptoms such as perspective taking, social communication, and repetitive behavior. Recent research suggests that multilingualism may have a beneficial impact on EF abilities, especially in children with ASD. However, there remains a lack of comprehensive understanding regarding the relationships between multilingualism, EF, and core symptoms in children with ASD. Here, we examined these associations in 7-12-year-old children with and without ASD (N = 116; 53 ASD, Mean age = 9.94 years). Results suggest that multilingual children have stronger parent-reported inhibition, shifting, and perspective-taking skills than monolingual children. Furthermore, we found a significant interaction between diagnosis and multilingual status on inhibition, such that the effects of multilingualism were stronger for children with ASD than typically developing (TD) children. Finally, we found indirect effects of multilingualism on perspective taking, social communication, and repetitive behaviors mediated by EF skills. These results demonstrate the supportive influences multilingual experience might have on bolstering EF and reducing ASD-related symptoms.

Executive function deficits in attention-deficit/hyperactivity disorder and autism spectrum disorder

Executive function deficits have been reported in both autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). However, little is known regarding which, if any, of these impairments are unique vs. shared in children with ADHD versus ASD. In this Review, we provide an overview of the current literature with a critical eye toward diagnostic, measurement, and third-variable considerations that should be leveraged to provide more definitive answers. We conclude that the field's understanding of ASD and ADHD executive function profiles is highly limited because most research on one disorder has failed to account for their co-occurrence and the presence of symptoms of the other disorder; a vast majority of studies have relied on traditional neuropsychological tests and/or informant-rated executive function scales that have poor specificity and construct validity; and most studies have been unable to account for the well-documented between-person heterogeneity within and across disorders. Currently, the most parsimonious conclusion is that children with ADHD and/or ASD tend to perform moderately worse than neurotypical children on a broad range of neuropsychological tests. However, the extent to which these difficulties are unique vs. shared, or attributable to impairments in specific executive functions subcomponents, remains largely unknown. We end with focused recommendations for future research that we believe will advance this important line of inquiry.

Refining our Understanding of Anxiety in Autistic Youth: Examining the Role of Behavioral Inflexibility

Prior research has demonstrated that cognitive inflexibility is associated with anxiety in autistic individuals. Everyday patterns of behavioral inflexibility (e.g. observable inflexible behavior in the context of the need to change or adapt and that is manifested in real-world everyday settings) is common in autism and can be distinguished from performance on discrete cognitive tasks that tap flexible attention, learning, or decision-making. The purpose of this study was to extend this prior work on inflexibility in autism but with measures specifically developed with input from stakeholders (caregivers and clinicians) for autistic youth designed to measure everyday behavioral inflexibility (BI). We characterized anxiety in a large sample of autistic (N = 145) and non-autistic youth (N = 91), ages 3 to 17 years, using the Parent Rated Anxiety Scale for Autism Spectrum Disorder (PRAS-ASD). Further, we sought to understand how BI, measured via the Behavioral Inflexibility Scale (BIS), predicted anxiety compared to other variables known to increase anxiety in youth (chronological age, IQ, autism diagnosis, assigned sex at birth). Autistic youth had higher parent-related anxiety and BI compared to non-autistic youth. BI was the strongest predictor of anxiety scores, irrespective of diagnosis. Overall, our findings highlight the importance of BI to the understanding of anxiety in autistic youth.

Probing cognitive flexibility in Shank2-deficient mice: Effects of D-cycloserine and NMDAR signaling hub dynamics

Neurodevelopmental disorders such as autism spectrum disorder (ASD) have a heterogeneous etiology but are largely associated with genetic factors. Robust evidence from recent human genetic studies has linked mutations in the Shank2 gene to idiopathic ASD. Modeling these Shank2 mutations in animal models recapitulates behavioral changes, e.g. impaired social interaction and repetitive behavior of ASD patients. Shank2-deficient mice exhibit NMDA receptor (NMDAR) hypofunction and associated behavioral deficits. Of note, NMDARs are strongly implicated in cognitive flexibility. Their hypofunction, e.g. observed in schizophrenia, or their pharmacological inhibition leads to impaired cognitive flexibility. However, the association between Shank2 mutations and cognitive flexibility is poorly understood. Using Shank2-deficient mice, we explored the role of Shank2 in cognitive flexibility measured by the attentional set shifting task (ASST) and whether ASST performance in Shank2-deficient mice can be modulated by treatment with the partial NMDAR agonist D-cycloserine (DCS). Furthermore, we investigated the effects of Shank2 deficiency, ASST training, and DCS treatment on the expression level of NMDAR signaling hub components in the orbitofrontal cortex (OFC), including NMDAR subunits (GluN2A, GluN2B, GluN2C), phosphoglycerate dehydrogenase and serine racemase. Surprisingly, Shank2 deficiency did not affect ASST performance or alter the expression of the investigated NMDAR signaling hub components. Importantly, however, DCS significantly improved ASST performance, demonstrating that positive NMDAR modulation facilitates cognitive flexibility. Furthermore, DCS increased the expression of GluN2A in the OFC, but not that of other NMDAR signaling hub components. Our findings highlight the potential of DCS as a pharmacological intervention to improve cognitive flexibility impairments downstream of NMDAR modulation and substantiate the key role of NMDAR in cognitive flexibility.

Examining the relationship between functional connectivity and broader autistic traits in non-autistic children

In the current study, we used functional near-infrared spectroscopy (fNIRS) to examine functional connectivity (FC) in relation to measures of cognitive flexibility and autistic features in non-autistic children. Previous research suggests that disruptions in FC between brain regions may underlie the cognitive and behavioral traits of autism. Moreover, research has identified a broader autistic phenotype (BAP), which refers to a set of behavioral traits that fall along a continuum of behaviors typical for autism but which do not cross a clinically relevant threshold. Thus, by examining FC in relation to the BAP in non-autistic children, we can better understand the spectrum of behaviors related to this condition and their neural basis. Results indicated age-related differences in performance across three measures of cognitive flexibility, as expected given the rapid development of this skill within this time period. Additionally, results showed that across the flexibility tasks, measures of autistic traits were associated with weaker FC along the executive control network, though task performance was not associated with FC. These results suggest that behavioral scores may be less sensitive than neural measures to autistic traits. Further, these results corroborate the use of broader autistic traits and the BAP to better understand disruptions to neural function associated with autism.

Relationships between Sensory Processing and Executive Functions in Children with Combined ASD and ADHD Compared to Typically Developing and Single Disorder Groups

The prevalence of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) is increasing, with a tendency for co-occurrence. Some studies indicate a connection between atypical sensory processing and executive function. This study aims to explore the distinctive etiology of executive function deficits in children with ASD+ADHD by investigating the relationship between sensory processing and executive function, comparing children with ASD, ASD+ADHD, ADHD, and typically developing children (TD).

METHOD

Sensory Profile 2 (SP-2) and Behavior Rating Inventory of Executive Function 2 (BRIEF-2) were measured in 120 school-aged children. The results of the above scales were compared across these four groups, and correlation and regression analyses between BRIEF2 and SP2 were conducted.

RESULTS

Our research revealed varying levels of atypical sensory processing and executive function anomalies across the three neurodevelopmental disorder groups compared to the TD group. The ASD+ADHD group showed particularly significant differences. The heightened emotional problems observed in ASD+ADHD children may be associated with more prominent atypical sensory processing. Variance analysis of inhibitory function revealed differences between ASD+ADHD and ADHD children, suggesting distinct etiological mechanisms for attention issues between ASD+ADHD and ADHD.

CONCLUSIONS

ASD+ADHD represents a phenotype distinct from both ASD and ADHD. Special consideration should be given to interventions for children with ASD+ADHD. The results of this study may offer a new perspective on understanding the occurrence of ASD+ADHD and potential individualized intervention methods.

Repetitive Behaviors in Autism and Obsessive-Compulsive Disorder: A Systematic Review

PURPOSE

Obsessive-compulsive disorder (OCD) and autism are characterized by the presence of repetitive behaviors. Differentiating between repetitive behaviors attributable to a diagnosis of autism, and those attributable to OCD, poses challenges for differential and co-occurring diagnosis. Differentiation is important to inform appropriate supports and interventions for phenotypically similar but functionally distinct behaviors. In this systematic review, the quantitative literature was examined to explore the similarities and differences in repetitive behaviors (including restricted and repetitive behaviors and interests, and obsessive-compulsive behaviors) in autistic individuals and those with OCD, and those with co-occurring diagnoses, in terms of: (1) expression, (2) content, and (3) associated factors.

METHODS

Thirty-one studies were identified that compared repetitive behaviors in autistic individuals, individuals with OCD, or individuals with both diagnoses.

RESULTS

The results suggest considerable overlap in the intensity and content of repetitive behaviors between groups. The findings of this review highlight that research aimed specifically at understanding similarities and differences in repetitive behaviors between autistic individuals and individuals with OCD is limited and frequently only compare at total score or composite measure levels.

CONCLUSION

Further research into differences in the presentation of repetitive behaviors at a subscale and item level is required to inform clearer differentiation of specific behaviors in autism versus OCD. Understanding and more accurately differentiating is essential for efficient diagnosis, effective treatment, and better outcomes.

Magnitude representation of preschool children with autism spectrum condition

LAY ABSTRACT

The mathematical abilities of children with autism spectrum condition have been understudied. Magnitude representation (e.g. presenting the number of a collection of objects) is a fundamental numerical ability presented since early infancy and is correlated with children's later learning of formal mathematics. It remains unclear about whether children with autism spectrum condition differ from their peers without autism spectrum condition in precision of magnitude representations. This study compared preschool children with and without autism spectrum condition in their precision of magnitude representation with an approximate number comparison task, in which children compared two sets of dots without counting and chose the set with more dots. Children with autism spectrum condition exhibited the lower numerical comparison accuracy (i.e. the weaker magnitude representation) than their peers without autism spectrum condition. This difference existed even when multiple general cognitive abilities (working memory, inhibitory control, and nonverbal intelligence) and language abilities were statistically controlled. Moreover, the individual difference of the numerical comparison accuracy was larger in children with autism spectrum condition than without autism spectrum condition. These findings suggest that children with autism spectrum condition are at risk of weaker magnitude representation from an early age, emphasizing the need for specialized mathematics education or interventions to support their learning. In addition, the large variance in the precision of their magnitude representation suggests that individualized mathematics interventions are needed for children with autism spectrum condition.

A meta-analysis of cognitive flexibility in autism spectrum disorder

Cognitive flexibility is a fundamental process that underlies adaptive behaviour in response to environmental change. Studies examining the profile of cognitive flexibility in autism spectrum disorder (ASD) have reported inconsistent findings. To address whether difficulties with cognitive flexibility are characteristic of autism, we conducted a random-effects meta-analysis and employed subgroup analyses and meta-regression to assess the impact of relevant moderator variables such as task, outcomes, and age. Fifty-nine studies were included and comprised of 2122 autistic individuals without intellectual disabilities and 2036 neurotypical controls, with an age range of 4 to 85 years. The results showed that autistic individuals have greater difficulties with cognitive flexibility, with an overall statistically significant small to moderate effect size. Subgroup analyses revealed a significant difference between task outcomes, with perseverative errors obtaining the largest effect size. In summary, the present meta-analysis highlights the existence of cognitive flexibility difficulties in autistic people, in the absence of learning disabilities, but also that this profile is characterised by substantial heterogeneity. Potential contributing factors are discussed.

Endophenotype trait domains for advancing gene discovery in autism spectrum disorder

Autism spectrum disorder (ASD) is associated with a diverse range of etiological processes, including both genetic and non-genetic causes. For a plurality of individuals with ASD, it is likely that the primary causes involve multiple common inherited variants that individually account for only small levels of variation in phenotypic outcomes. This genetic landscape creates a major challenge for detecting small but important pathogenic effects associated with ASD. To address similar challenges, separate fields of medicine have identified endophenotypes, or discrete, quantitative traits that reflect genetic likelihood for a particular clinical condition and leveraged the study of these traits to map polygenic mechanisms and advance more personalized therapeutic strategies for complex diseases. Endophenotypes represent a distinct class of biomarkers useful for understanding genetic contributions to psychiatric and developmental disorders because they are embedded within the causal chain between genotype and clinical phenotype, and they are more proximal to the action of the gene(s) than behavioral traits. Despite their demonstrated power for guiding new understanding of complex genetic structures of clinical conditions, few endophenotypes associated with ASD have been identified and integrated into family genetic studies. In this review, we argue that advancing knowledge of the complex pathogenic processes that contribute to ASD can be accelerated by refocusing attention toward identifying endophenotypic traits reflective of inherited mechanisms. This pivot requires renewed emphasis on study designs with measurement of familial co-variation including infant sibling studies, family trio and quad designs, and analysis of monozygotic and dizygotic twin concordance for select trait dimensions. We also emphasize that clarification of endophenotypic traits necessarily will involve integration of transdiagnostic approaches as candidate traits likely reflect liability for multiple clinical conditions and often are agnostic to diagnostic boundaries. Multiple candidate endophenotypes associated with ASD likelihood are described, and we propose a new focus on the analysis of "endophenotype trait domains" (ETDs), or traits measured across multiple levels (e.g., molecular, cellular, neural system, neuropsychological) along the causal pathway from genes to behavior. To inform our central argument for research efforts toward ETD discovery, we first provide a brief review of the concept of endophenotypes and their application to psychiatry. Next, we highlight key criteria for determining the value of candidate endophenotypes, including unique considerations for the study of ASD. Descriptions of different study designs for assessing endophenotypes in ASD research then are offered, including analysis of how select patterns of results may help prioritize candidate traits in future research. We also present multiple candidate ETDs that collectively cover a breadth of clinical phenomena associated with ASD, including social, language/communication, cognitive control, and sensorimotor processes. These ETDs are described because they represent promising targets for gene discovery related to clinical autistic traits, and they serve as models for analysis of separate candidate domains that may inform understanding of inherited etiological processes associated with ASD as well as overlapping neurodevelopmental disorders.

Exploring the role of autistic traits and eating disorder psychopathology on mentalising ability in the general population

BACKGROUND

This study evaluated the role of overlapping traits and characteristics related to autism spectrum disorder (autism) and anorexia nervosa (AN) in the general population, and the impact of these traits on mentalising ability.

METHODS

A sample of young adults (N = 306), aged 18-25 years, was recruited to complete an online study that consisted of 4 measures: the Autism-Spectrum Quotient, Eating Disorder Examination Questionnaire, the Mentalization Scale, and the Reading the Mind in the Eyes task.

RESULTS

Higher levels of autistic traits, particularly difficulty with attention switching, were associated with increased eating disorder psychopathology. Overall, autistic traits and eating disorder psychopathology were related among females, but not males. Difficulty with attention switching, however, was related to eating disorder psychopathology among both females and males. Autistic traits also appear to have a greater role in mentalising ability than does eating disorder psychopathology.

CONCLUSION

The role of attention switching in overlapping traits of autism and eating disorder psychopathology needs to be more comprehensively evaluated by future research, as does the role of biological sex. Expanded knowledge in this field will help to better understand and evaluate symptoms at presentation, leading to clearer diagnoses and potentially better treatment outcomes.

Atypical cognitive training-induced learning and brain plasticity and their relation to insistence on sameness in children with autism

Children with autism spectrum disorders (ASDs) often display atypical learning styles; however, little is known regarding learning-related brain plasticity and its relation to clinical phenotypic features. Here, we investigate cognitive learning and neural plasticity using functional brain imaging and a novel numerical problem-solving training protocol. Children with ASD showed comparable learning relative to typically developing children but were less likely to shift from rule-based to memory-based strategy. While learning gains in typically developing children were associated with greater plasticity of neural representations in the medial temporal lobe and intraparietal sulcus, learning in children with ASD was associated with more stable neural representations. Crucially, the relation between learning and plasticity of neural representations was moderated by insistence on sameness, a core phenotypic feature of ASD. Our study uncovers atypical cognitive and neural mechanisms underlying learning in children with ASD, and informs pedagogical strategies for nurturing cognitive abilities in childhood autism.

Human generalization of internal representations through prototype learning with goal-directed attention

The world is overabundant with feature-rich information obscuring the latent causes of experience. How do people approximate the complexities of the external world with simplified internal representations that generalize to novel examples or situations? Theories suggest that internal representations could be determined by decision boundaries that discriminate between alternatives, or by distance measurements against prototypes and individual exemplars. Each provide advantages and drawbacks for generalization. We therefore developed theoretical models that leverage both discriminative and distance components to form internal representations via action-reward feedback. We then developed three latent-state learning tasks to test how humans use goal-oriented discrimination attention and prototypes/exemplar representations. The majority of participants attended to both goal-relevant discriminative features and the covariance of features within a prototype. A minority of participants relied only on the discriminative feature. Behaviour of all participants could be captured by parameterizing a model combining prototype representations with goal-oriented discriminative attention.

Atypical cognitive training-induced learning and brain plasticity and their relation to insistence on sameness in children with autism

Children with autism spectrum disorders (ASD) often display atypical learning styles, however little is known regarding learning-related brain plasticity and its relation to clinical phenotypic features. Here, we investigate cognitive learning and neural plasticity using functional brain imaging and a novel numerical problem-solving training protocol. Children with ASD showed comparable learning relative to typically developing children but were less likely to shift from rule-based to memory-based strategy. Critically, while learning gains in typically developing children were associated with greater plasticity of neural representations in the medial temporal lobe and intraparietal sulcus, learning in children with ASD was associated with more stable neural representations. Crucially, the relation between learning and plasticity of neural representations was moderated by insistence on sameness, a core phenotypic feature of ASD. Our study uncovers atypical cognitive and neural mechanisms underlying learning in children with ASD, and informs pedagogical strategies for nurturing cognitive abilities in childhood autism.

The Executive Function Account of Repetitive Behavior: Evidence From Rubinstein-Taybi Syndrome

In this study, we focus on Rubinstein-Taybi syndrome (RTS) to explore the associations between executive function deficits and repetitive behaviors. Thirty individuals with RTS completed direct assessments of inhibition, working memory and set-shifting. Informants completed repetitive behavior and executive function questionnaires. Repetitive questions were associated with poorer inhibition and working memory. Stereotypy was associated with poorer inhibition. Adherence to routines was associated with poorer set-shifting, but only on the parental report measure. No other associations were evident. There is evidence of an association between specific repetitive behaviors and executive functioning in RTS, suggesting executive dysfunction may underpin behavioral difference in RTS. The findings point towards specific associations that are of interest for further research across populations in which repetitive behaviors are present.

Male DAT Val559 Mice Exhibit Compulsive Behavior under Devalued Reward Conditions Accompanied by Cellular and Pharmacological Changes

Identified across multiple psychiatric disorders, the dopamine (DA) transporter (DAT) Ala559Val substitution triggers non-vesicular, anomalous DA efflux (ADE), perturbing DA neurotransmission and behavior. We have shown that DAT Val559 mice display a waiting impulsivity and changes in cognitive performance associated with enhanced reward motivation. Here, utilizing a within-subject, lever-pressing paradigm designed to bias the formation of goal-directed or habitual behavior, we demonstrate that DAT Val559 mice modulate their nose poke behavior appropriately to match context, but demonstrate a perseverative checking behavior. Although DAT Val559 mice display no issues with the cognitive flexibility required to acquire and re-learn a visual pairwise discrimination task, devaluation of reward evoked habitual reward seeking in DAT Val559 mutants in operant tasks regardless of reinforcement schedule. The direct DA agonist apomorphine also elicits locomotor stereotypies in DAT Val559, but not WT mice. Our observation that dendritic spine density is increased in the dorsal medial striatum (DMS) of DAT Val559 mice speaks to an imbalance in striatal circuitry that might underlie the propensity of DAT Val559 mutants to exhibit compulsive behaviors when reward is devalued. Thus, DAT Val559 mice represent a model for dissection of how altered DA signaling perturbs circuits that normally balance habitual and goal-directed behaviors.

What affects gestural learning in children with and without Autism? The role of prior knowledge and imitation

The present study examined whether prior knowledge to the learning target and imitation during learning affected learning outcomes in preschool children with autism spectrum disorder (ASD, N = 22) compared to their typically developing (TD, N = 15) peers. Children's gestural skills in recognizing and producing the target gestures before and after the training, as well as their imitative behavior during the training were coded. Results showed that consistent prior knowledge benefited gestural learning in both groups. Besides, only children with ASD were hindered by inconsistent prior knowledge. Notably, the effect of imitation was not significant in the ASD group. In conclusion, the learning process in children with ASD may differ from those with typical development, suggesting special-designed interventions are required.

Brief report: replication of the psychometric characteristics of the behavioral inflexibility scale in an independent sample

The Behavioral Inflexibility Scale (BIS) is a recently developed measure of behavioral inflexibility, defined as rigid patterns of behavior that contrast with the need to be flexible when the situation calls for it. In this study, we sought to replicate previous findings on the psychometric properties of the BIS in a community sample. Data for this study were collected using in-person assessments of 163 autistic and 95 non-autistic children ages 3-17 and included the BIS, measures of social-communication ability and repetitive behaviors, and an assessment of cognitive ability. Our findings replicate the psychometric properties of the BIS, indicating that the measure is a valid measure of behavioral inflexibility in ASD.

Abnormal Prefrontal Functional Connectivity Is Associated with Inflexible Information Processing in Patients with Autism Spectrum Disorder (ASD): An fNIRS Study

Individuals with autism spectrum disorder (ASD) are characterized by impairments in flexibly acquiring and maintaining new information, as well as in applying learned information for problem solving. However, the neural mechanism underpinning such impairments remains unclear. This study investigated the flexibility in the acquisition and application of visual information in ASD (aged 14−21) when they performed the Wisconsin Card Sorting Test (WCST). Behavioral data including response accuracy and latency, and prefrontal hemodynamic data measured by functional near-infrared spectroscopy (fNIRS), were collected when individuals performed WCST. Canonical general linear model and functional connectivity analyses were performed to examine the prefrontal activation and synchronization patterns, respectively. Results showed that although ASD individuals (n = 29) achieved comparable accuracy rates when compared with age- and intelligence quotient (IQ)-matched typically developing (TD; n = 26) individuals (F1,53 = 3.15, p = 0.082), ASD individuals needed significantly more time to acquire and apply WCST card sorting rules (F1,53 = 17.92, p < 0.001). Moreover, ASD individuals showed significantly lower prefrontal functional connectivity than TD individuals during WCST (F1,42 = 9.99, p = 0.003). The hypoconnectivity in ASD individuals was highly significant in the right lateral PFC in the acquisition condition (p = 0.005) and in the bilateral lateral PFC in the application condition (ps = 0.006). Furthermore, slower WCST reaction time was correlated with lower bilateral lateral PFC functional connectivity only in the application condition (ps = 0.003) but not the acquisition condition. Impairment in information acquisition and application is evident in ASD individuals and is mediated by processing speed, which is associated with lower functional connectivity in the bilateral lateral PFC when these individuals apply learned rules to solve novel problems.

Gray matter volume alteration is associated with insistence on sameness and cognitive flexibility in autistic youth

Restricted and repetitive behaviors (RRBs) are hallmark characteristics of autism spectrum disorder (ASD). Previous studies suggest that insistence on sameness (IS) characterized as higher-order RRBs may be a promising subgrouping variable for ASD. Cognitive inflexibility may underpin IS behaviors. However, the neuroanatomical correlates of IS and associated cognitive functions remain unclear. We analyzed data from 140 autistic youth and 124 typically developing (TD) youth (mean age = 15.8 years). Autistic youth were stratified by median-split based on three current IS items in the autism diagnostic interview-revised into two groups (high, HIS, n = 70, and low, LIS, n = 70). Differences in cognitive flexibility were assessed by the Cambridge neuropsychological test automated battery (CANTAB). T1-weighted brain structural images were analyzed using voxel-based morphometry (VBM) to identify differences in gray matter (GM) volume among the three groups. GM volume of regions showing group differences was then correlated with cognitive flexibility. The HIS group showed decreased GM volumes in the left supramarginal gyrus compared to the LIS group and increased GM volumes in the vermis VIII and left cerebellar lobule VIII compared to TD individuals. We did not find significant correlations between regional GM volumes and extra-dimensional shift errors. IS may be a unique RRB component and a potentially valuable stratifier of ASD. However, the neurocognitive underpinnings require further clarification. LAY SUMMARY: The present study found parietal, temporal and cerebellar gray matter volume alterations in autistic youth with greater insistence on sameness. The findings suggest that insistence on sameness may be a useful feature to parse the heterogeneity of the autism spectrum yet further research investigating the underlying neurocognitive mechanism is warranted.

Repetitive Restricted Behaviors in Autism Spectrum Disorder: From Mechanism to Development of Therapeutics

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by deficits in social communication, social interaction, and repetitive restricted behaviors (RRBs). It is usually detected in early childhood. RRBs are behavioral patterns characterized by repetition, inflexibility, invariance, inappropriateness, and frequent lack of obvious function or specific purpose. To date, the classification of RRBs is contentious. Understanding the potential mechanisms of RRBs in children with ASD, such as neural connectivity disorders and abnormal immune functions, will contribute to finding new therapeutic targets. Although behavioral intervention remains the most effective and safe strategy for RRBs treatment, some promising drugs and new treatment options (e.g., supplementary and cell therapy) have shown positive effects on RRBs in recent studies. In this review, we summarize the latest advances of RRBs from mechanistic to therapeutic approaches and propose potential future directions in research on RRBs.

Cholinergic neurons in the pedunculopontine nucleus guide reversal learning by signaling the changing reward contingency

Cognitive flexibility enables effective switching between mental processes to generate appropriate responses. Cholinergic neurons (CNs) within the pedunculopontine nucleus (PPN) are associated with many functions, but their contribution to cognitive flexibility remains poorly understood. Here we measure PPN cholinergic activities using calcium indicators during the attentional set-shifting task. We find that PPN CNs exhibit increasing activities correlated with rewards during each stage and error trials in reversal stages, indicating sensitivity to rule switching. Inhibition of PPN cholinergic activity selectively impairs reversal learning, which improves with PPN CN activation. Activation of PPN CNs projecting to the substantia nigra pars compacta, mediodorsal thalamus, and parafascicular nucleus in a time-locked manner with reward improves reversal learning. Therefore, PPN CNs may encode not only reward signals but also the information of changing reward contingency that contributes to guiding reversal learning through output projections to multiple nuclei that participate in flexibility.

Atypical Neural Responses of Cognitive Flexibility in Parents of Children With Autism Spectrum Disorder

Impaired cognitive flexibility has been repeatedly demonstrated in autism spectrum disorder (ASD). There is strong evidence for genetic involvement in ASD. First-degree relatives of individuals with ASD may show mild deficits in cognitive inflexibility. The present study investigated cognitive flexibility and its neuroelectrophysiological mechanisms in first-degree relatives of individuals with ASD to assess its potential familiality. Forty-five biological parents of individuals/children with ASD (pASD) and thirty-one biological parents of typically developing individuals/children (pTD), matched by gender, age, and IQ, were enrolled. The broad autism phenotype questionnaire (BAPQ) and cognitive flexibility inventory (CFI) were used to quantitatively assess autistic traits and cognitive flexibility in daily life, respectively. The task-switching paradigm was used to evaluate the behavioral flexibility in a structured assessment situation. Event-related potentials (ERPs) induced by this paradigm were also collected. Results showed that compared with the pTD group, the pASD group had lower CFI scores (t = −2.756, p < 0.01), while both groups showed an equivalent “switch cost” in the task-switching task (p > 0.05). Compared with the pTD group, the pASD group induced greater N2 amplitude at F3, F4, Fz, and C4 (F = 3.223, p < 0.05), while P3 amplitude and latency did not differ between the two groups. In addition, there was a significant negative correlation between the CFI total scores and BAPQ total scores in the pASD group (r = −0.734, p < 0.01). After controlling for age and IQ, the N2 amplitude in the frontal lobe of pASD was negatively correlated with the CFI total scores under the repetition sequence (r = −0.304, p = 0.053). These results indicated that pASD had deficit in cognitive flexibility at the self-reported and neurological levels. The cognitive flexibility difficulties of parents of children with ASD were related to autistic traits. These findings support that cognitive flexibility is most likely a neurocognitive endophenotype of ASD, which is worthy of further investigation.

Exposure to family stressful life events in autistic children: Longitudinal associations with mental health and the moderating role of cognitive flexibility

Mental health problems are prevalent in autistic youth, but the underpinning mechanisms are not well explored. In neurotypical youth, stressful life events are an established risk factor for mental health problems. This study tested longitudinal bidirectional associations between family-level stressful life events and mental health problems and whether these were moderated by cognitive flexibility, in a cohort of autistic children (N = 247). Family-stressful life events, assessed using the parent-reported Family Inventory of Life Events and Changes, and mental health problems, assessed using the teacher-reported Child Behavior Checklist Internalizing and Externalizing Symptoms subscales, were measured at multiple points between 7 and 11 years. Analyses showed no significant pathways from internalizing or externalizing symptoms to family-stressful life events or from family-stressful life events to internalizing or externalizing symptoms. There was some evidence of moderation by cognitive flexibility; the family-stressful life events to internalizing symptoms pathway was non-significant in the group with typical shifting ability but significant in the group with clinically significant shifting problems. Information about family-level stressful life event exposure and cognitive flexibility may be helpful in identifying autistic youth who may be at higher risk of developing mental health problems. Established risk factors for mental health problems in neurotypical populations are relevant for understanding mental health in autistic youth.

Understanding the psycho-social context for a new early intervention for resistance to change that aims to strike a beneficial balance between structure and flexibility

BACKGROUND

Emotional and behavioural problems linked to changes to expectations - resistance to change - are linked to disability in neurodevelopmental disorders, including autism spectrum disorder (ASD), Prader-Willi (PWS) and fragile X syndromes (FXS). Structuring routines is best practice for minimising current resistance to change. But complete structure is impractical and flexibility in early life may actually reduce later resistance by supporting cognitive development. We aimed to examine the psycho-social context of families with children at risk of developing resistance to change so as to identify design requirements for an intervention that strikes a beneficial balance between structure and flexibility.

METHODS

Thirty-six caregivers of children aged 4-12 years (17 ASD, 15 PWS, and 4 FXS) took part in an interview designed collaboratively with 12 professional stakeholders.

RESULTS

Children need to feel like they are in control of flexibility but they also need support in choice making, understanding plans (using individually tailored visuals) and anxiety reduction. Caregivers need an accessible approach that they have full control over, and which they can tailor for their child. Caregivers also need clear guidance, education and support around structure and flexibility.

CONCLUSIONS

We propose a digital approach which addresses the needs identified. It tackles the most perplexing challenge by presenting flexibility to children in the context of a game that children can feel they have full control over, whilst caregivers can maintain control in reality. Furthermore, individualised support for children and caregivers would be enabled.

Advancing the Personalization of Assessment and Intervention in Autistic Adolescents and Young Adults by Targeting Self-Determination and Executive Processes

As autistic adolescents and young adults navigate the transition to adulthood, there is a need to partner with them to identify strengths and needed supports to enable goal-directed actions. This article conceptually integrates research on self-determination, defined by Causal Agency Theory, and executive processes in autism to provide direction for future research and practice. We describe how integrating research on self-determination and executive processes could enable autistic adolescents and young adults to be engaged in the process of assessing executive processes and self-determination. We discuss how this can better inform personalization of supports for self-determination interventions by focusing on support needs related to executive processes, including inhibitory control and cognitive flexibility, from a strengths-based perspective. We discuss how this can enable self-determination interventions that promote outcomes aligned with the values of the autistic community.

Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders

BACKGROUND

Autism Spectrum Disorder (ASD) is considered a neurodevelopmental condition that is characterized by alterations in social interaction and communication, as well as patterns of restrictive and repetitive behaviors (RRBs). RRBs are defined as broad behaviors that comprise stereotypies, insistence on sameness, and attachment to objects or routines. RRBs can be divided into lower-level behaviors (motor, sensory, and object-manipulation behaviors) and higher-level behaviors (restrictive interests, insistence on sameness, and repetitive language). According to the DSM-5, the grade of severity in ASD partially depends on the frequency of RRBs and their consequences for disrupting the life of patients, affecting their adaptive skills, and increasing the need for parental support.

METHODS

We conducted a systematic review to examine the biopsychological correlates of the symptomatic domains of RRBs according to the type of RRBs (lower- or higher-level). We searched for articles from the National Library of Medicine (PubMed) using the terms: autism spectrum disorders, ASD, and autism-related to executive functions, inhibitory control, inflexibility, cognitive flexibility, hyper or hypo connectivity, and behavioral approaches. For describing the pathophysiological mechanism of ASD, we also included animal models and followed PRISMA guidelines.

RESULTS

One hundred and thirty-one articles were analyzed to explain the etiology, continuance, and clinical evolution of these behaviors observed in ASD patients throughout life.

CONCLUSIONS

Biopsychological correlates involved in the origin of RRBs include alterations in a) neurotransmission system, b) brain volume, c) inadequate levels of growth factors, d) hypo- or hyper-neural connectivity, e) impairments in behavioral inhibition, cognitive flexibility, and monitoring and f) non-stimulating environments. Understanding these lower- and higher-level of RRBs can help professionals to improve or design novel therapeutic strategies.

Behavioral Inflexibility Across Two Neurogenetic Conditions: Down Syndrome and Fragile X Syndrome

Behavioral inflexibility (BI) has been highlighted to occur across genetic and neurodevelopmental disorders. This study characterized BI in two common neurogenetic conditions: Fragile X syndrome (FXS) and Down syndrome (DS). Caregivers of children with FXS (N = 56; with ASD = 28; FXS only = 28) and DS (N = 146) completed the Behavioral Inflexibility Scale (BIS) via an online survey. Total BIS scores were higher in FXS+ASD than both FXS only and DS (p <.001). Most endorsed items were similar across the three groups, but scores were higher in the FXS+ASD group. In all groups, BI associated with other clinical variables (receptive behaviors, anxiety, social communication). The current data suggest that BI is variable across neurogenetic conditions and higher in individuals with comorbid ASD.

The Monash Autism-ADHD genetics and neurodevelopment (MAGNET) project design and methodologies: a dimensional approach to understanding neurobiological and genetic aetiology

Background

ASD and ADHD are prevalent neurodevelopmental disorders that frequently co-occur and have strong evidence for a degree of shared genetic aetiology. Behavioural and neurocognitive heterogeneity in ASD and ADHD has hampered attempts to map the underlying genetics and neurobiology, predict intervention response, and improve diagnostic accuracy. Moving away from categorical conceptualisations of psychopathology to a dimensional approach is anticipated to facilitate discovery of data-driven clusters and enhance our understanding of the neurobiological and genetic aetiology of these conditions. The Monash Autism-ADHD genetics and neurodevelopment (MAGNET) project is one of the first large-scale, family-based studies to take a truly transdiagnostic approach to ASD and ADHD. Using a comprehensive phenotyping protocol capturing dimensional traits central to ASD and ADHD, the MAGNET project aims to identify data-driven clusters across ADHD-ASD spectra using deep phenotyping of symptoms and behaviours; investigate the degree of familiality for different dimensional ASD-ADHD phenotypes and clusters; and map the neurocognitive, brain imaging, and genetic correlates of these data-driven symptom-based clusters.

Methods

The MAGNET project will recruit 1,200 families with children who are either typically developing, or who display elevated ASD, ADHD, or ASD-ADHD traits, in addition to affected and unaffected biological siblings of probands, and parents. All children will be comprehensively phenotyped for behavioural symptoms, comorbidities, neurocognitive and neuroimaging traits and genetics.

Conclusion

The MAGNET project will be the first large-scale family study to take a transdiagnostic approach to ASD-ADHD, utilising deep phenotyping across behavioural, neurocognitive, brain imaging and genetic measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-021-00457-3.

Drug development for Autism Spectrum Disorder (ASD): Progress, challenges, and future directions

In 2017, facing lack of progress and failures encountered in targeted drug development for Autism Spectrum Disorder (ASD) and related neurodevelopmental disorders, the ISCTM with the ECNP created the ASD Working Group charged to identify barriers to progress and recommending research strategies for the field to gain traction. Working Group international academic, regulatory and industry representatives held multiple in-person meetings, teleconferences, and subgroup communications to gather a wide range of perspectives on lessons learned from extant studies, current challenges, and paths for fundamental advances in ASD therapeutics. This overview delineates the barriers identified, and outlines major goals for next generation biomedical intervention development in ASD. Current challenges for ASD research are many: heterogeneity, lack of validated biomarkers, need for improved endpoints, prioritizing molecular targets, comorbidities, and more. The Working Group emphasized cautious but unwavering optimism for therapeutic progress for ASD core features given advances in the basic neuroscience of ASD and related disorders. Leveraging genetic data, intermediate phenotypes, digital phenotyping, big database discovery, refined endpoints, and earlier intervention, the prospects for breakthrough treatments are substantial. Recommendations include new priorities for expanded research funding to overcome challenges in translational clinical ASD therapeutic research.

Brief Report: An Exploration of Cognitive Flexibility of Autistic Adolescents with Low Intelligence Using the Wisconsin Card Sorting Task

Cognitive flexibility (CF) is the ability to shift between concepts or rules. Difficulty with CF is associated with autism (i.e., ASD) as it contributes to repetitive behaviours. However, little is known about CF skills of autistic adolescents with low intelligence. This study uses the Wisconsin Card Sorting Task (WCST) to assess the CF of 36 adolescents, all with a Weschler full-scale IQ between 50 and 85, 14 of whom had an ASD diagnosis. The results indicated no statistically significant differences in WCST performance between those with and without ASD. It was also found that performance IQ significantly contributed to the WCST performance in the ASD group only, suggesting an autism-specific role of non-verbal cognitive functioning in CF.

Brief Report: A Preliminary Study of the Relationship between Repetitive Behaviors and Concurrent Executive Function Demands in Children with Autism Spectrum Disorder

The present study evaluated the hypothesis that the strength of the relationship between executive function (EF) and repetitive behaviors and restricted interests (RBRI) symptomatology is moderated by the degree to which concurrent demands are placed on multiple aspects of EF. An eye movement task was used to evaluate inhibition and task switching ability (both together and in isolation) in a sample of 22 children with autism spectrum disorder (ASD). The Repetitive Behavior Scale-Revised (RBS-R) was used to assess the severity of RBRI symptoms. Results provide preliminary support for the aforementioned hypothesis. RBS-R scores were significantly correlated with task performance when simultaneous demands were placed on switching and inhibition; however, no such relationship was found for inhibition-only or switching-only task conditions.

Measuring the Functional Impact of Behavioral Inflexibility in Children with Autism Using the Behavioral Inflexibility Scale: Clinical Interview (BIS-CI)

For individuals with autism spectrum disorder (ASD), behavioral inflexibility can affect multiple domains of functioning and family life. The objective of this study was to develop and validate a clinical interview version of the Behavioral Inflexibility Scale. Trained interviewers conducted interviews with parents of 144 children with ASD and 70 typically developing children (ages: 3-17 years). Using exploratory factor analysis, the Behavioral Inflexibility Scale-Clinical Interview (BIS-CI) was found to be unidimensional. Reliability data indicated the measure was internally consistent (α = 0.80), achieved excellent inter-rater reliability (ICC = 0.97) and test-retest reliability (ICC = 0.87). These findings demonstrate that the BIS-CI is a reliable and valid measure to determine the functional impact of behavioral inflexibility.

The Multi-Targeting Ligand ST-2223 with Histamine H3 Receptor and Dopamine D2/D3 Receptor Antagonist Properties Mitigates Autism-Like Repetitive Behaviors and Brain Oxidative Stress in Mice

Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by social and communicative impairments, as well as repetitive and restricted behaviors (RRBs). With the limited effectiveness of current pharmacotherapies in treating repetitive behaviors, the present study determined the effects of acute systemic treatment of the novel multi-targeting ligand ST-2223, with incorporated histamine H₃ receptor (H₃R) and dopamine D₂/D₃ receptor affinity properties, on ASD-related RRBs in a male Black and Tan BRachyury (BTBR) mouse model of ASD. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly mitigated the increase in marble burying and self-grooming, and improved reduced spontaneous alternation in BTBR mice (all p < 0.05). Similarly, reference drugs memantine (MEM, 5 mg/kg, i.p.) and aripiprazole (ARP, 1 mg/kg, i.p.), reversed abnormally high levels of several RRBs in BTBR (p < 0.05). Moreover, ST-2223 palliated the disturbed anxiety levels observed in an open field test (all p < 0.05), but did not restore the hyperactivity parameters, whereas MEM failed to restore mouse anxiety and hyperactivity. In addition, ST-2223 (5 mg/kg, i.p.) mitigated oxidative stress status by decreasing the elevated levels of malondialdehyde (MDA), and increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in different brain parts of treated BTBR mice (all p < 0.05). These preliminary in vivo findings demonstrate the ameliorative effects of ST-2223 on RRBs in a mouse model of ASD, suggesting its pharmacological prospective to rescue core ASD-related behaviors. Further confirmatory investigations on its effects on various brain neurotransmitters, e.g., dopamine and histamine, in different brain regions are still warranted to corroborate and expand these initial data.

Executive Function Skills Are Linked to Restricted and Repetitive Behaviors: Three Correlational Meta Analyses

There is a consensus on the centrality of restricted and repetitive behaviors (RRBs) in the diagnosis of Autism Spectrum Disorder (ASD), yet the origins of these behaviors are still debated. We reconsider whether executive function (EF) accounts of RRBs should be revisited. EF deficits and high levels of RRBs are often pronounced in individuals with ASD and are also prevalent in young typically developing children. Despite this, the evidence is mixed, and there has been no systematic attempt to evaluate the relationship across studies and between task batteries. We examine recent evidence, and in three highly powered random-effects analyses (N = 2964), examine the strength of the association between RRB levels and performance on set shifting, inhibitory control, and parental-report based EF batteries. The analyses confirm significant associations between high levels of the behaviors and poor EF skills. Moreover, the associations remained stable across typical development and in individuals with ASD and across different types of EF measures. These meta-analyses consolidate recent evidence identifying that cognitive mechanisms correlate with high RRBs that are seen in individuals with ASD, as well as in typical development. We propose that the EF account may be critical for guiding future interventions in ASD research. LAY SUMMARY: Restricted and repetitive behaviors (RRBs) are diagnostic criteria for Autism yet also common in typical development, and if they persist over time some can have a negative impact on learning and social acceptance. The present meta-analyses found that high levels of RRBs related to poor performance on set-shifting and inhibitory control tasks, as well as high ratings on parental report scales. Future studies should create interventions that aim to improve these skills as they may help manage challenging RRBs.

Valproic acid treated female Long-Evans rats are impaired on attentional set-shifting

Autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by social deficits, communication impairments, restrictive behaviors, and cognitive flexibility deficits. The valproic acid (VPA) model of autism has been widely used to examine changes in rodent behavior and neurobiology to better understand ASD. This study examined social and anxiety behavior as well as cognitive flexibility in VPA and control offspring. Results for social behavior were consistent with prior studies showing reduced sociability in VPA rats and increased self-grooming, which may be viewed as a repetitive behavior. VPA rats also had deficits in performing the set-shifting task, with female VPA rats demonstrating greater impairment compared to female control rats and male VPA rats. These results support the hypothesis that females diagnosed with ASD may suffer from different symptoms and present a unique behavioral profile compared to males with ASD. Female VPA rats were also less likely to form an attentional set; offering evidence that the VPA model of autism is encompassing executive function deficits similar to those observed in humans with ASD.

Modeling flexible behavior in childhood to adulthood shows age-dependent learning mechanisms and less optimal learning in autism in each age group

Flexible behavior is critical for everyday decision-making and has been implicated in restricted, repetitive behaviors (RRB) in autism spectrum disorder (ASD). However, how flexible behavior changes developmentally in ASD remains largely unknown. Here, we used a developmental approach and examined flexible behavior on a probabilistic reversal learning task in 572 children, adolescents, and adults (ASD N = 321; typical development [TD] N = 251). Using computational modeling, we quantified latent variables that index mechanisms underlying perseveration and feedback sensitivity. We then assessed these variables in relation to diagnosis, developmental stage, core autism symptomatology, and associated psychiatric symptoms. Autistic individuals showed on average more perseveration and less feedback sensitivity than TD individuals, and, across cases and controls, older age groups showed more feedback sensitivity than younger age groups. Computational modeling revealed that dominant learning mechanisms underpinning flexible behavior differed across developmental stages and reduced flexible behavior in ASD was driven by less optimal learning on average within each age group. In autistic children, perseverative errors were positively related to anxiety symptoms, and in autistic adults, perseveration (indexed by both task errors and model parameter estimates) was positively related to RRB. These findings provide novel insights into reduced flexible behavior in relation to clinical symptoms in ASD.

Late attentional processes potentially compensate for early perceptual multisensory integration deficits in children with autism: evidence from evoked potentials

Sensory processing deficits and altered long-range connectivity putatively underlie Multisensory Integration (MSI) deficits in Autism Spectrum Disorder (ASD). The present study set out to investigate non-social MSI stimuli and their electrophysiological correlates in young neurotypical adolescents and adolescents with ASD. We report robust MSI effects at behavioural and electrophysiological levels. Both groups demonstrated normal behavioural MSI. However, at the neurophysiological level, the ASD group showed less MSI-related reduction of the visual P100 latency, greater MSI-related slowing of the auditory P200 and an overall temporally delayed and spatially constrained onset of MSI. Given the task design and patient sample, and the age of our participants, we argue that electro-cortical indices of MSI deficits in ASD: (a) can be detected in early-adolescent ASD, (b) occur at early stages of perceptual processing, (c) can possibly be compensated by later attentional processes, (d) thus leading to normal MSI at the behavioural level.

Simultaneous Blockade of Histamine H3 Receptors and Inhibition of Acetylcholine Esterase Alleviate Autistic-Like Behaviors in BTBR T+ tf/J Mouse Model of Autism

Autism spectrum disorder (ASD) is a heterogenous neurodevelopmental disorder defined by persistent deficits in social interaction and the presence of patterns of repetitive and restricted behaviors. The central neurotransmitters histamine (HA) and acetylcholine (ACh) play pleiotropic roles in physiological brain functions that include the maintenance of wakefulness, depression, schizophrenia, epilepsy, anxiety and narcolepsy, all of which are found to be comorbid with ASD. Therefore, the palliative effects of subchronic systemic treatment using the multiple-active test compound E100 with high H₃R antagonist affinity and AChE inhibitory effect on ASD-like behaviors in male BTBR T+tf/J (BTBR) mice as an idiopathic ASD model were assessed. E100 (5, 10 and 15 mg/kg, i.p.) dose-dependently palliated social deficits of BTBR mice and significantly alleviated the repetitive/compulsive behaviors of tested animals. Moreover, E100 modulated disturbed anxiety levels, but failed to modulate hyperactivity parameters, whereas the reference AChE inhibitor donepezil (DOZ, one milligram per kilogram) significantly obliterated the increased hyperactivity measures of tested mice. Furthermore, E100 mitigated the increased levels of AChE activity in BTBR mice with observed effects comparable to that of DOZ and significantly reduced the number of activated microglial cells compared to the saline-treated BTBR mice. In addition, the E100-provided effects on ASD-like parameters, AChE activity, and activated microglial cells were entirely reversed by co-administration of the H₃R agonist (R)-α-methylhistamine (RAM). These initial overall results observed in an idiopathic ASD mice model show that E100 (5 mg/kg) alleviated the assessed behavioral deficits and demonstrate that simultaneous targeting of brain histaminergic and cholinergic neurotransmissions is crucial for palliation of ASD-like features, albeit further in vivo assessments on its effects on brain levels of ACh as well as HA are still needed.

The Dual-Active Histamine H3 Receptor Antagonist and Acetylcholine Esterase Inhibitor E100 Alleviates Autistic-Like Behaviors and Oxidative Stress in Valproic Acid Induced Autism in Mice

The histamine H3 receptor (H3R) functions as auto- and hetero-receptors, regulating the release of brain histamine (HA) and acetylcholine (ACh), respectively. The enzyme acetylcholine esterase (AChE) is involved in the metabolism of brain ACh. Both brain HA and ACh are implicated in several cognitive disorders like Alzheimer’s disease, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with autistic spectrum disorder (ASD). Therefore, the novel dual-active ligand E100 with high H3R antagonist affinity (hH3R: K_i = 203 nM) and balanced AChE inhibitory effect (EeAChE: IC₅₀ = 2 µM and EqBuChE: IC₅₀ = 2 µM) was investigated on autistic-like sociability, repetitive/compulsive behaviour, anxiety, and oxidative stress in male C57BL/6 mice model of ASD induced by prenatal exposure to valproic acid (VPA, 500 mg/kg, intraperitoneal (i.p.)). Subchronic systemic administration with E100 (5, 10, and 15 mg/kg, i.p.) significantly and dose-dependently attenuated sociability deficits of autistic (VPA) mice in three-chamber behaviour (TCB) test (all p < 0.05). Moreover, E100 significantly improved repetitive and compulsive behaviors by reducing the increased percentage of marbles buried in marble-burying behaviour (MBB) (all p < 0.05). Furthermore, pre-treatment with E100 (10 and 15 mg/kg, i.p.) corrected decreased anxiety levels (p < 0.05), however, failed to restore hyperactivity observed in elevated plus maze (EPM) test. In addition, E100 (10 mg/kg, i.p.) mitigated oxidative stress status by increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), and decreasing the elevated levels of malondialdehyde (MDA) in the cerebellar tissues (all p < 0.05). Additionally, E100 (10 mg/kg, i.p.) significantly reduced the elevated levels of AChE activity in VPA mice (p < 0.05). These results demonstrate the promising effects of E100 on in-vivo VPA-induced ASD-like features in mice, and provide evidence that a potent dual-active H3R antagonist and AChE inhibitor (AChEI) is a potential drug candidate for future therapeutic management of autistic-like behaviours.

MECP2 Duplication Causes Aberrant GABA Pathways, Circuits and Behaviors in Transgenic Monkeys: Neural Mappings to Patients with Autism

MECP2 gain-of-function and loss-of-function in genetically engineered monkeys recapitulates typical phenotypes in patients with autism, yet where MECP2 mutation affects the monkey brain and whether/how it relates to autism pathology remain unknown. Here we report a combination of gene-circuit-behavior analyses including MECP2 coexpression network, locomotive and cognitive behaviors, and EEG and fMRI findings in 5 MECP2 overexpressed monkeys (Macaca fascicularis; 3 females) and 20 wild-type monkeys (Macaca fascicularis; 11 females). Whole-genome expression analysis revealed MECP2 coexpressed genes significantly enriched in GABA-related signaling pathways, whereby reduced β-synchronization within fronto-parieto-occipital networks was associated with abnormal locomotive behaviors. Meanwhile, MECP2-induced hyperconnectivity in prefrontal and cingulate networks accounted for regressive deficits in reversal learning tasks. Furthermore, we stratified a cohort of 49 patients with autism and 72 healthy controls of 1112 subjects using functional connectivity patterns, and identified dysconnectivity profiles similar to those in monkeys. By establishing a circuit-based construct link between genetically defined models and stratified patients, these results pave new avenues to deconstruct clinical heterogeneity and advance accurate diagnosis in psychiatric disorders.SIGNIFICANCE STATEMENT Autism spectrum disorder (ASD) is a complex disorder with co-occurring symptoms caused by multiple genetic variations and brain circuit abnormalities. To dissect the gene-circuit-behavior causal chain underlying ASD, animal models are established by manipulating causative genes such as MECP2 However, it is unknown whether such models have captured any circuit-level pathology in ASD patients, as demonstrated by human brain imaging studies. Here, we use transgenic macaques to examine the causal effect of MECP2 overexpression on gene coexpression, brain circuits, and behaviors. For the first time, we demonstrate that the circuit abnormalities linked to MECP2 and autism-like traits in the monkeys can be mapped to a homogeneous ASD subgroup, thereby offering a new strategy to deconstruct clinical heterogeneity in ASD.

Metacognition and behavioral regulation predict distinct aspects of social functioning in autism spectrum disorder

Executive function (EF) deficits are common in autism spectrum disorder (ASD), and previous studies suggest that EF may influence or predict social functioning. Thus, EF is a potential treatment target in this population. However, the nature of how specific metacognition and behavioral regulation components of EF may differentially impact social function remains unclear. The goal of the current study was to examine the relationships between sub-components of EF (e.g., working memory, shifting, inhibition, etc.) and social functioning as measured by parent ratings on the Behavior Rating Inventory of Executive Functioning (BRIEF) and the Social Responsiveness Scale (SRS), while controlling for the influence of age, sex, and IQ. A second goal was to examine whether BRIEF scores were predictive of clinician-rated measures of ASD symptoms. Behavioral data were acquired from the Autism Brain Imaging Data Exchange-II database and included 106 children with ASD (ages 5-13). Based on analysis of parent ratings, self-monitoring skills predicted social awareness; shifting ability predicted social cognition; working memory and monitoring skills predicted social communication; initiation predicted social motivation; and shifting ability predicted restrictive and repetitive behaviors among children with ASD. Parent ratings on the BRIEF did not predict clinician-rated measures of ASD symptoms; this requires further study. Overall, the current findings indicate that metacognition and behavioral regulation both contribute to social functioning in ASD, although they each have distinct patterns of influence on different aspects of social functioning. These findings have promising implications for tailoring social interventions for ASD that target specific EF skills.

Parents report fewer executive functioning problems and repetitive behaviors in young dual-language speakers with autism

More dual language learners (DLLs) are being identified early with autism spectrum disorder (ASD). However, many families are still being advised against dual language exposure, despite a lack of evidence of negative impacts on language development in ASD. Research in typically developing children has noted advantages for bilinguals in domains such as executive functioning and social skills, but less is known about the effects in ASD. The present study evaluated differences in executive functioning and social communication in young children (n = 55) with ASD. Dual-language learners with ASD had significantly fewer parent reported executive functioning problems and repetitive behaviors; parent-reported social communication skills were generally comparable across groups. Our findings indicate that the bilingual advantage in executive functioning may extend to children with neurodevelopmental conditions.

Development of the Behavioral Inflexibility Scale for Children with Autism Spectrum Disorder and Other Developmental Disabilities

Behavior inflexibility (BI) refers to rigid patterns of behavior that contrast with the need to be adaptable to changing environmental demands. We developed a parent-reported outcome measure of BI for children with autism spectrum disorder (ASD) and other developmental disabilities with a multi-step iterative process. A pool of 62 candidate items was generated through expert panel feedback, review of existing scales and focus groups. A consensus process was used to generate the final 38 items. Parents of 943 children (age range, 3-18 years; average, 11.4 years; 79% boys) with ASD completed an online survey. One hundred thirty-three parents rated their child twice within 3 weeks (average = 16.5 days). A series of factor analyses suggested that the 38 items measured a single construct. Scores had a weak correlation with level of functioning (-0.12) and did not differ based on sex. Scores had a negligible correlation with age (-0.07), although measurement invariance was not supported. The mean total score for the Behavioral Inflexibility Scale (BIS) was normally distributed. Internal consistency was α = 0.97 and temporal stability was r = 0.92. Correlations with parent ratings on the subscales of the Repetitive Behavior Scale-Revised varied from 0.48 to 0.89. The correlation with parent ratings on the Social Communication Questionnaire total score was 0.52. Our data show that BI in children with ASD ranges significantly from mild to severe and that the 38-item BIS is valid and reliable. Autism Res 2020, 13: 489-499. © 2020 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: We developed a parent-completed rating scale of behavior inflexibility (BI) for children with developmental disabilities using a multistep process. The Behavioral Inflexibility Scale (BIS) contains 38 questions rated on a 6-point scale. Parents of 943 children with autism spectrum disorder (ASD) completed an online survey. We examined associations between the BIS and other scales and demographic variables. The BIS is valid and reliable. BI in children with ASD ranges from mild to severe.

Building functional connectivity neuromarkers of behavioral self-regulation across children with and without Autism Spectrum Disorder

Behavioral self-regulation develops rapidly during childhood and struggles in this area can have lifelong negative outcomes. Challenges with self-regulation are common to several neurodevelopmental conditions, including Autism Spectrum Disorder (ASD). Little is known about the neural expression of behavioral regulation in children with and without neurodevelopmental conditions.

We examined whole-brain brain functional correlations (FC) and behavioral regulation through connectome predictive modelling (CPM). CPM is a data-driven protocol for developing predictive models of brain–behavior relationships and assessing their potential as ‘neuromarkers’ using cross-validation. The data stems from the ABIDE II and comprises 276 children with and without ASD (8–13 years).

We identified networks whose FC predicted individual differences in behavioral regulation. These network models predicted novel individuals’ inhibition and shifting from FC data in both a leave-one-out, and split halves, cross-validation. We observed commonalities and differences, with inhibition relying on more posterior networks, shifting relying on more anterior networks, and both involving regions of the DMN.

Our findings substantially add to our knowledge on the neural expressions of inhibition and shifting across children with and without a neurodevelopmental condition. Given the numerous behavioral issues that can be quantified dimensionally, refinement of whole-brain neuromarker techniques may prove useful in the future.

Familiality of behavioral flexibility and response inhibition deficits in autism spectrum disorder (ASD)

Background

Diminished cognitive control, including reduced behavioral flexibility and behavioral response inhibition, has been repeatedly documented in autism spectrum disorder (ASD). We evaluated behavioral flexibility and response inhibition in probands and their parents using a family trio design to determine the extent to which these cognitive control impairments represent familial traits associated with ASD.

Methods

We examined 66 individuals with ASD (probands), 135 unaffected biological parents, and 76 typically developing controls. Participants completed a probabilistic reversal learning task (PRL) and a stop-signal task (SST) to assess behavioral flexibility and response inhibition respectively. Rates of PRL and SST errors were examined across groups, within families, and in relation to clinical and subclinical traits of ASD. Based on prior findings that subclinical broader autism phenotypic (BAP) traits may co-segregate within families and reflect heritable risk factors, we also examined whether cognitive control deficits were more prominent in families in which parents showed BAP features (BAP+).

Results

Probands and parents each showed increased rates of PRL and SST errors relative to controls. Error rates across tasks were not related. SST error rates inter-correlated among probands and their parents. PRL errors were more severe in BAP+ parents and their children relative to BAP- parents and their children. For probands of BAP+ parents, PRL and SST error rates were associated with more severe social-communication abnormalities and repetitive behaviors, respectively.

Conclusion

Reduced behavioral flexibility and response inhibition are present among probands and their unaffected parents, but represent unique familial deficits associated with ASD that track with separate clinical issues. Specifically, behavioral response inhibition impairments are familial in ASD and manifest independently from parental subclinical features. In contrast, behavioral flexibility deficits are selectively present in families with BAP characteristics, suggesting they co-segregate in families with parental subclinical social, communication, and rigid personality traits. Together, these findings provide evidence that behavioral flexibility and response inhibition impairments track differentially with ASD risk mechanisms and related behavioral traits.

Afobazole Alleviates Cognitive Rigidity in Experimental Model of Autism Spectrum Disorders

Afobazole (10 mg/kg) alleviated cognitive rigidity in BALB/c mice, a phenotypic model of autism spectrum disorders. It improved spatial memory and retraining in T-maze with drinking reinforcement and restored the retrieval of acquired skill during reversal learning in Morris water maze.