Altered connectivity and action model formation in autism is autism

Sensory Phenotypes in Autism: Making a Case for the Inclusion of Sensory Integration Functions

Sensory features are part of the diagnostic criteria for autism and include sensory hypo/hyper reactivity and unusual sensory interest; however, additional sensory differences, namely differences in sensory integration, have not been routinely explored. This study characterized sensory integration differences in a cohort of children (n = 93) with a confirmed diagnosis of autism (5-9 years) using a standardized, norm-referenced battery. Mean z scores, autism diagnostic scores, and IQ are reported. Participants showed substantial deficits in tactile perception, praxis, balance, visual perception, and visual-motor skills. Relationship with autism diagnostic test scores were weak or absent. Findings suggest additional sensory difficulties that are not typically assessed or considered when characterizing sensory features in autism. These data have implications for a greater understanding of the sensory features in the autism phenotype and the development of personalized treatments.

Connectivity differences between inferior frontal gyrus and mentalizing network in autism as compared to developmental coordination disorder and non-autistic youth

Prior studies have compared neural connectivity during mentalizing tasks in autism (ASD) to non-autistic individuals and found reduced connectivity between the inferior frontal gyrus (IFG) and mentalizing regions. However, given that the IFG is involved in motor processing, and about 80% of autistic individuals have motor-related difficulties, it is necessary to explore if these differences are specific to ASD or instead similar across other developmental motor disorders, such as developmental coordination disorder (DCD). Participants (29 ASD, 20 DCD, 31 typically developing [TD]; ages 8-17) completed a mentalizing task in the fMRI scanner, where they were asked to think about why someone was performing an action. Results indicated that the ASD group, as compared to both TD and DCD groups, showed significant functional connectivity differences when mentalizing about other's actions. The left IFG seed revealed ASD connectivity differences with the: bilateral temporoparietal junction (TPJ), left insular cortex, and bilateral dorsolateral prefrontal cortex (DLPFC). Connectivity differences using the right IFG seed revealed ASD differences in the: left insula, and right DLPFC. These results indicate that connectivity differences between the IFG, mentalizing regions, emotion and motor processing regions are specific to ASD and not a result of potentially co-occurring motor differences.

Autism-Related Differences in Cortical Activation When Observing, Producing, and Imitating Communicative Gestures: An fNIRS Study

Children with autism spectrum disorder (ASD) have difficulties in gestural communication during social interactions. However, the neural mechanisms involved in naturalistic gestural communication remain poorly understood. In this study, cortical activation patterns associated with gestural communication were examined in thirty-two children with and without ASD (mean age: 11.0 years, SE: 0.6 years). Functional near-infrared spectroscopy (fNIRS) was used to record cortical activation while children produced, observed, or imitated communicative gestures. Children with ASD demonstrated more spatial and temporal errors when performing and imitating communicative gestures. Although both typically developing (TD) children and children with ASD showed left-lateralized cortical activation during gesture production, children with ASD showed hyperactivation in the middle/inferior frontal gyrus (MIFG) during observation and imitation, and hypoactivation in the middle/superior temporal gyrus (MSTG) during gesture production compared to their TD peers. More importantly, children with ASD exhibited greater MSTG activation during imitation than during gesture production, suggesting that imitation could be an effective intervention strategy to engage cortical regions crucial for processing and producing gestures. Our study provides valuable insights into the neural mechanisms underlying gestural communication difficulties in ASD, while also identifying potential neurobiomarkers that could serve as objective measures for evaluating intervention effectiveness in children with ASD.

Measuring Dyspraxia in Autism using a Five-Minute Praxis Exam

Background

Difficulties with praxis, the ability to perform learned skilled movements, have been robustly demonstrated in autism spectrum disorder (autism). However, praxis assessment is not routinely included in autism characterization batteries, in part because it is traditionally time consuming to administer and score. We test whether dyspraxia in autism can be captured with a brief measure.

Method

Youth with autism (n = 41) and matched typically developing controls (n = 32), aged 8 to 16 years, completed a 5-minute praxis battery. The 19-item battery included four subtests: gesture to command, tool use, familiar imitation, and meaningless imitation. Video recordings were coded for error types and compared to participant characterization variables.

Results

Consistent with research using a lengthy battery, autistic youth made more errors overall, with a large effect size. Groups demonstrated similar distributions of error types, suggesting that dyspraxia in autism is not limited to a particular error form. In the autism group, praxis was associated with adaptive functioning, but not autism traits.

Conclusions

A shortened battery is sufficiently sensitive to praxis differences between autistic and typically developing youth, increasing the feasibility of including praxis within clinical assessments or larger research batteries aimed at testing relationships with downstream skills.

Altered Relationship between Functional Connectivity and Fiber-Bundle Structure in High-Functioning Male Adults with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder characterized by abnormalities in structure and function of the brain. However, how ASD affects the relationship between fiber-bundle microstructures and functional connectivity (FC) remains unclear. Here, we analyzed structural and functional images of 26 high-functioning adult males with ASD, alongside 26 age-, gender-, and full-scale IQ-matched typically developing controls (TDCs) from the BNI dataset in the ABIDE database. We utilized fixel-based analysis to extract microstructural information from fiber tracts, which was then used to predict FC using a multilinear model. Our results revealed that the structure-function relationships in both ASD and TDC cohorts were strongly aligned in the primary cortex but decoupled in the high-order cortex, and the ASD patients exhibited reduced structure-function relationships throughout the cortex compared to the TDCs. Furthermore, we observed that the disrupted relationships in ASD were primarily driven by alterations in FC rather than fiber-bundle microstructures. The structure-function relationships in the left superior parietal cortex, right precentral and inferior temporal cortices, and bilateral insula could predict individual differences in clinical symptoms of ASD patients. These findings underscore the significance of altered relationships between fiber-bundle microstructures and FC in the etiology of ASD.

Cortico-Cerebellar neurodynamics during social interaction in Autism Spectrum Disorders

BACKGROUND

Exploring neural network dynamics during social interaction could help to identify biomarkers of Autism Spectrum Disorders (ASD). A cerebellar involvement in autism has long been suspected and recent methodological advances now enable studying cerebellar functioning in a naturalistic setting. Here, we investigated the electrophysiological activity of the cerebro-cerebellar network during real-time social interaction in ASD. We focused our analysis on theta oscillations (3-8 Hz), which have been associated with large-scale coordination of distant brain areas and might contribute to interoception, motor control, and social event anticipation, all skills known to be altered in ASD.

METHODS

We combined the Human Dynamic Clamp, a paradigm for studying realistic social interactions using a virtual avatar, with high-density electroencephalography (HD-EEG). Using source reconstruction, we investigated power in the cortex and the cerebellum, along with coherence between the cerebellum and three cerebral-cortical areas, and compared our findings in a sample of participants with ASD (n = 107) and with typical development (TD) (n = 33). We developed an open-source pipeline to analyse neural dynamics at the source level from HD-EEG data.

RESULTS

Individuals with ASD showed a significant increase in theta band power over the cerebellum and the frontal and temporal cortices during social interaction compared to resting state, along with significant coherence increases between the cerebellum and the sensorimotor, frontal and parietal cortices. However, a phase-based connectivity measure did not support a strict activity increase in the cortico-cerebellar functional network. We did not find any significant differences between the ASD and the TD group.

CONCLUSIONS

This exploratory study uncovered increases in the theta band activity of participants with ASD during social interaction, pointing at the presence of neural interactions between the cerebellum and cerebral networks associated with social cognition. It also emphasizes the need for complementary functional connectivity measures to capture network-level alterations. Future work will focus on optimizing artifact correction to include more participants with TD and increase the statistical power of group-level contrasts.

Motor differences in autism during a human-robot imitative gesturing task

BACKGROUND

Difficulty with imitative gesturing is frequently observed as a clinical feature of autism. Current practices for assessment of imitative gesturing ability-behavioral observation and parent report-do not allow precise measurement of specific components of imitative gesturing performance, instead relying on subjective judgments. Advances in technology allow researchers to objectively quantify the nature of these movement differences, and to use less socially stressful interaction partners (e.g., robots). In this study, we aimed to quantify differences in imitative gesturing between autistic and neurotypical development during human-robot interaction.

METHODS

Thirty-five autistic (n = 19) and neurotypical (n = 16) participants imitated social gestures of an interactive robot (e.g., wave). The movements of the participants and the robot were recorded using an infrared motion-capture system with reflective markers on corresponding head and body locations. We used dynamic time warping to quantify the degree to which the participant's and robot's movement were aligned across the movement cycle and work contribution to determine how each joint angle was producing the movements.

FINDINGS

Results revealed differences between autistic and neurotypical participants in imitative accuracy and work contribution, primarily in the movements requiring unilateral extension of the arm. Autistic individuals imitated the robot less accurately and used less work at the shoulder compared to neurotypical individuals.

INTERPRETATION

These findings indicate differences in autistic participants' ability to imitate an interactive robot. These findings build on our understanding of the underlying motor control and sensorimotor integration mechanisms that support imitative gesturing in autism which may aid in identifying appropriate intervention targets.

fNIRS-Based Differences in Cortical Activation during Tool Use, Pantomimed Actions, and Meaningless Actions between Children with and without Autism Spectrum Disorder (ASD)

Children with autism spectrum disorder (ASD) have difficulties with tool use and pantomime actions. The current study utilized functional near-infrared spectroscopy (fNIRS) to examine the neural mechanisms underlying these gestural difficulties. Thirty-one children with and without ASD (age (mean ± SE) = 11.0 ± 0.6) completed a naturalistic peg-hammering task using an actual hammer (hammer condition), pantomiming hammering actions (pantomime condition), and performing meaningless actions with similar joint motions (meaningless condition). Children with ASD exhibited poor praxis performance (praxis error: TD = 17.9 ± 1.7; ASD = 27.0 ± 2.6, p < 0.01), which was significantly correlated with their cortical activation (R = 0.257 to 0.543). Both groups showed left-lateralized activation, but children with ASD demonstrated more bilateral activation during all gestural conditions. Compared to typically developing children, children with ASD showed hyperactivation of the inferior parietal lobe and hypoactivation of the middle/inferior frontal and middle/superior temporal regions. Our findings indicate intact technical reasoning (typical left-IPL activation) but atypical visuospatial and proprioceptive processing (hyperactivation of the right IPL) during tool use in children with ASD. These results have important implications for clinicians and researchers, who should focus on facilitating/reducing the burden of visuospatial and proprioceptive processing in children with ASD. Additionally, fNIRS-related biomarkers could be used for early identification through early object play/tool use and to examine neural effects following gesture-based interventions.

Strategies to Support Learning of Gross Motor Tasks in Children with Autism Spectrum Disorder: A Scoping Review

AIMS

Children with autism spectrum disorder (ASD) display motor difficulties that may impact social and communication interactions and participation in everyday activities. These difficulties may be related to a difference in the way they learn new skills. Therefore, strategies to support motor learning to optimize skill acquisition and retention may be beneficial. This scoping review described current motor learning strategies used to optimize acquisition, retention, transfer, and generalizability of motor tasks in children with ASD.

METHODS

Three databases were searched from inception through 2021. Studies were included if they involved participants with ASD ≤ 18 years old, evaluated learning of a novel gross motor task, manipulated a motor learning variable, and were written in English.

RESULTS

Twenty-two articles met eligibility criteria. Most articles examined strategies that manipulated the instruction of task, with few articles examining feedback or practice. Skill acquisition was the most represented motor learning outcome, with fewer studies examining retention, transfer, or generalizability.

CONCLUSIONS

Positive results in 95% of the articles suggest that the use of support strategies to optimize motor learning is feasible and beneficial for children with ASD, and that modifications to instruction, feedback, and practice schedules should be considered in motor interventions.

New Methods for Unraveling Imitation Accuracy Differences Between Children with Autism and Typically Developing Peers

This study applies methods used in sign language and gesture research to better understand reduced imitation accuracy (IA) of actions and gestures in children with autism spectrum disorder (ASD), and we addressed contrasting theories on IA in ASD and the role of objects and meanings in imitation. Eight male children with ASD with a mean chronological age (CA) of 86.76 months (SD = 10.74, range 70.5-104.4) and 22 male and female peers with typical development (TD) and a mean CA of 85.44 months (SD = 7.95, range 73.4-96.7) imitated videos of an adult performing actions with objects, representational gestures, conventional gestures and meaningless gestures. We measured accuracy as ability to effectively reproduce features (handshape, palm orientation, location, movement direction and type) and timing (speed) of observed actions/gestures, after ruling out cases of specular (i.e., mirror-like) versus anatomical imitation. Results highlighted significantly lower feature and timing accuracy in children with ASD with respect to the TD group across tasks, and these findings supported sensory-motor theories of IA in ASD. Our data also showed the different impact of objects and meanings within groups. Overall, these results suggest validity to our assessment method and suggested the importance of considering both discreet variables (i.e., variables describing action/gesture feature accuracy, e.g. handshape, movement direction) and continuous variables (i.e., kinematic variables, e.g. speed) in evaluating IA in autism.

Transcriptomic analysis of isolated and pooled human postmortem cerebellar Purkinje cells in autism spectrum disorders

At present, the neuronal mechanisms underlying the diagnosis of autism spectrum disorder (ASD) have not been established. However, studies from human postmortem ASD brains have consistently revealed disruptions in cerebellar circuitry, specifically reductions in Purkinje cell (PC) number and size. Alterations in cerebellar circuitry would have important implications for information processing within the cerebellum and affect a wide range of human motor and non-motor behaviors. Laser capture microdissection was performed to obtain pure PC populations from a cohort of postmortem control and ASD cases and transcriptional profiles were compared. The 427 differentially expressed genes were enriched for gene ontology biological processes related to developmental organization/connectivity, extracellular matrix organization, calcium ion response, immune function and PC signaling alterations. Given the complexity of PCs and their far-ranging roles in response to sensory stimuli and motor function regulation, understanding transcriptional differences in this subset of cerebellar cells in ASD may inform on convergent pathways that impact neuronal function.

Effect of Longitudinal Practice in Real and Virtual Environments on Motor Performance, Physical Activity and Enjoyment in People with Autism Spectrum Disorder: A Prospective Randomized Crossover Controlled Trial

(1) Background: People with ASD commonly present difficulty performing motor skills and a decline in physical activity (PA) level and low enjoyment of PA. We aimed to evaluate whether longitudinal practice of an activity in virtual and real environments improves motor performance and whether this improvement is transferred to a subsequent practice when changing the environment, promoting PA and providing enjoyment; (2) Methods: People with ASD, aged between 10 and 16 years, were included and distributed randomly into two opposite sequences. The participants performed a 10 session protocol, with five sessions practicing in each environment (virtual or real). Heart rate measurement was carried out and an enjoyment scale was applied; (3) Results: 22 participants concluded the protocol. Sequence A (virtual first) presented an improvement in accuracy and precision and transferred this when changing environment; they also had a greater change in heart rate reserve. The majority of participants reported "fun" and "great fun" levels for enjoyment; (4) Conclusions: The virtual reality activity presented a higher level of difficulty, with greater gains in terms of transference to the real environment. Considering PA, our task provided very light to light activity and the majority of participants enjoyed the task.

A Bibliometric and Visualization Analysis of Motor Learning in Preschoolers and Children over the Last 15 Years

Motor learning enables preschoolers and children to acquire fundamental skills that are critical to their development. The current study sought to conduct a bibliometric and visualization analysis to provide a comprehensive overview of motor-learning progress in preschoolers and children over the previous 15 years. The number of studies is constantly growing, with the United States and Australia, as well as other productive institutions and authors, at the leading edge. The dominant disciplines were Neurosciences and Neurology, Psychology, Rehabilitation, and Sport Sciences. The journals Developmental Medicine & Child Neurology, Human Movement Science, Physical Therapy, Neuropsychology, Journal of Motor Behavior, and Journal of Experimental Child Psychology have been the most productive and influential in this regard. The most common co-citations for clinical symptoms were for cerebral palsy, developmental coordination disorder, and autism. Research has focused on language impairment (speech disorders, explicit learning, and instructor-control feedback), as well as effective intervention strategies. Advances in brain mechanisms and diagnostic indicators, as well as new intervention and rehabilitation technologies (virtual reality, transcranial magnetic stimulation, and transcranial direct current stimulation), have shifted research frontiers and progress. The cognitive process is critical in intervention, rehabilitation, and new technology implementation and should not be overlooked. Overall, our broad overview identifies three major areas: brain mechanism research, clinical practice (intervention and rehabilitation), and new technology application.

Autism-spectrum traits in neurotypicals predict the embodiment of manipulation knowledge about object concepts: Evidence from eyetracking

Sensorimotor-based theories of cognition predict that even subtle developmental motor differences, such as those characterizing autism spectrum disorder (ASD), impact how we represent the meaning of manipulable objects (e.g., faucet). Here, we test 85 neurotypical participants, who varied widely on the Adult Autism Spectrum Quotient (AQ), a measure intended to capture variability in ASD characteristics in the general adult population (participant scores were all below the clinical threshold for autism). Participants completed a visual world eyetracking task designed to assess the activation of conceptual representations of manipulable objects. Participants heard words referring to manually manipulable objects (e.g., faucet) while we recorded their eye movements to arrays of four objects: the named object, a related object typically manipulated similarly (e.g., jar), and two unrelated objects. Consistent with prior work, we observed more looks to the related object than to the unrelated ones (i.e., a manipulation-relatedness effect). This effect likely reflects the overlapping conceptual representations of objects sharing manipulation characteristics (e.g., faucet and jar), due to embodied sensorimotor properties being part of their representations. Critically, we observed—among typically developed young adults—that as AQ scores increased, manipulation-relatedness effects decreased. In contrast, in a visual control condition, in which a target object was paired with related objects of a similar shape (e.g., snake and rope), relatedness effects increased with AQ scores. The results show that AQ scores can predict variation in how object-concept representations are activated for typically developed individuals. More speculatively, they are consistent with the hypothesis that in individuals with ASD, differences in object-concept representations emerge at least in part via differences in sensorimotor experience.

Are Essential Trace Elements Effective in Modulation of Mental Disorders? Update and Perspectives

The emergence of mental disorders is associated with several risk factors including genetic and environmental susceptibility. A group of nutrients serves an especially important role in a number of essential neurodevelopmental processes through brain areas promoting the high degree of brain metabolism during early life, although almost all nutrients are needed. These include macronutrients and micronutrients (e.g., iron, magnesium, zinc, copper, selenium). Numerous nutritional psychiatry trials have been performed to examine the correlation of many individual nutrients with mental health, such as essential trace elements. The increased accumulation or lack of such components will facilitate an alternative metabolic pathway that can lead to many diseases and conditions of neurodevelopment. Mental functions have biochemical bases, so the impairment of such neurochemical mechanisms due to lack of trace elements can have mental effects. In psychological conditions such as depression, anxiety, schizophrenia, and autism, scientific studies demonstrate the putative role of trace element deficiency. Therefore, given the critical roles played by essential trace elements in the neurodevelopment and mental health, the effect of these elements' intake on the modulation of psychological functioning is reviewed.

Moving Toward Understanding Autism: Visual-Motor Integration, Imitation, and Social Skill Development

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a behavioral phenotype characterized by impaired development of social-communicative skills and excessive repetitive and stereotyped behaviors. Despite high phenotypic heterogeneity in ASD, a meaningful subpopulation of children with ASD (∼90%) show significant general motor impairment. More focused studies on the nature of motor impairment in ASD reveal that children with ASD are particularly impaired on tasks such as ball catching and motor imitation that require efficient visual-motor integration (VMI). Motor computational approaches also provide evidence for VMI impairment showing that children with ASD form internal sensorimotor representations that bias proprioceptive over visual feedback. Impaired integration of visual information to form internal representations of others' and the external world may explain observed impairments on VMI tasks and motor imitation of others. Motor imitation is crucial for acquiring both social and motor skills, and impaired imitation skill may contribute to the observed core behavioral phenotype of ASD. The current review examines evidence supporting VMI impairment as a core feature of ASD that may contribute to both impaired motor imitation and social-communicative skill development. We propose that understanding the neurobiological mechanisms underlying VMI impairment in ASD may be key to discovery of therapeutics to address disability in children and adults with ASD.

Modulation of motor cortical excitability by continuous theta-burst stimulation in adults with autism spectrum disorder

OBJECTIVE

To test whether change in motor evoked potential (ΔMEP) induced by continuous theta-burst stimulation (cTBS) of motor cortex (M1) distinguishes adults with autism spectrum disorder (ASD) from neurotypicals, and to explore the contribution of two common polymorphisms related to neuroplasticity.

METHODS

44 adult neurotypical (NT) participants (age 21-65, 34 males) and 19 adults with ASD (age 21-58, 17 males) prospectively underwent M1 cTBS. Their data were combined with previously obtained results from 35 NT and 35 ASD adults.

RESULTS

ΔMEP at 15 minutes post-cTBS (T15) was a significant predictor of diagnosis (p = 0.04) in the present sample (n=63). T15 remained a significant predictor in a larger sample (n=91) and when partially imputed based on T10-T20 from a yet-greater sample (N=133). T15 also remained a significant predictor of diagnosis among brain-derived neurotrophic factor (BDNF) Met+ and apolipoprotein E (APOE) ε4- subjects (p's < 0.05), but not among Met- or ε4+ subjects (p's > 0.19).

CONCLUSIONS

ΔMEP at T15 post-cTBS is a significant biomarker for adults with ASD, and its utility is modulated by BDNF and APOE polymorphisms.

SIGNIFICANCE

M1 cTBS response is a physiologic biomarker for adults with ASD in large samples, and controlling for BDNF and APOE polymorphisms can improve its diagnostic utility.

Influence of Ideational Praxis on the Development of Play and Adaptive Behavior of Children with Autism Spectrum Disorder: A Comparative Analysis

BACKGROUND

Traditionally, assessment of praxis skills in children with ASD has focused on the evaluation of aspects related to the planning and execution of actions. This study aimed to evaluate the ideational abilities of children with ASD and analyze possible relationships with the development of play and adaptive behaviors.

METHODS

40 children between 4 to 6 years (TD = 20; ASD = 20) were evaluated with the Test of Ideational Praxis, the Revised Knox Preschool Play Scale, and the Adaptive Behavior Assessment System II.

RESULTS

Statistically significant relationships were obtained between ideational praxis and play skills development (r = 0.649; p = 0.01), adaptive leisure behavior (r = 0.338; p = 0.04) and social adaptive behavior (r = 0.319; p = 0.04). Results of multiple linear regression models found a linear relationship between ideational praxis and play development (p = 0.005) and adaptive leisure skills (p = 0.004), but not with social interaction skills (p > 0.05).

CONCLUSIONS

Objective evaluation with a specific ideational praxis assessment facilitates understanding of the ideational abilities and widens understanding of praxis skills and their impact on play and adaptive behaviors in children with ASD.

The social brain in female autism: a structural imaging study of twins

A female advantage in social cognition (SoC) might contribute to women's underrepresentation in autism spectrum disorder (ASD). The latter could be underpinned by sex differences in social brain structure. This study investigated the relationship between structural social brain networks and SoC in females and males in relation to ASD and autistic traits in twins. We used a co-twin design in 77 twin pairs (39 female) aged 12.5 to 31.0 years. Twin pairs were discordant or concordant for ASD or autistic traits, discordant or concordant for other neurodevelopmental disorders or concordant for neurotypical development. They underwent structural magnetic resonance imaging and were assessed for SoC using the naturalistic Movie for the Assessment of Social Cognition. Autistic traits predicted reduced SoC capacities predominantly in male twins, despite a comparable extent of autistic traits in each sex, although the association between SoC and autistic traits did not differ significantly between the sexes. Consistently, within-pair associations between SoC and social brain structure revealed that lower SoC ability was associated with increased cortical thickness of several brain regions, particularly in males. Our findings confirm the notion that sex differences in SoC in association with ASD are underpinned by sex differences in brain structure.

A Data Driven Approach Reveals That Anomalous Motor System Connectivity is Associated With the Severity of Core Autism Symptoms

This study examined whether disruptions in connectivity involving regions critical for learning, planning, and executing movements are relevant to core autism symptoms. Spatially constrained ICA was performed using resting-state fMRI from 419 children (autism spectrum disorder (ASD) = 105; typically developing (TD) = 314) to identify functional motor subdivisions. Comparing the spatial organization of each subdivision between groups, we found voxels that contributed significantly less to the right posterior cerebellar component in children with ASD versus TD (P <0.001). Next, we examined the effect of diagnosis on right posterior cerebellar connectivity with all other motor subdivisions. The model was significant (P = 0.014) revealing that right posterior cerebellar connectivity with bilateral dorsomedial primary motor cortex was, on average, stronger in children with ASD, while right posterior cerebellar connectivity with left-inferior parietal lobule (IPL), bilateral dorsolateral premotor cortex, and supplementary motor area was stronger in TD children (all P ≤0.02). We observed a diagnosis-by-connectivity interaction such that for children with ASD, elevated social-communicative and excessive repetitive-behavior symptom severity were both associated with right posterior cerebellar-left-IPL hypoconnectivity (P ≤0.001). Right posterior cerebellar and left-IPL are strongly implicated in visuomotor processing with dysfunction in this circuit possibly leading to anomalous development of skills, such as motor imitation, that are crucial for effective social-communication. LAY SUMMARY: This study examines whether communication between various brain regions involved in the control of movement are disrupted in children with autism spectrum disorder (ASD). We show communication between the right posterior cerebellum and left IPL, a circuit important for efficient visual-motor integration, is disrupted in children with ASD and associated with the severity of ASD symptoms. These results may explain observations of visual-motor integration impairments in children with ASD that are associated with ASD symptom severity.

MEG Theta during Lexico-Semantic and Executive Processing Is Altered in High-Functioning Adolescents with Autism

Neuroimaging studies have revealed atypical activation during language and executive tasks in individuals with autism spectrum disorders (ASD). However, the spatiotemporal stages of processing associated with these dysfunctions remain poorly understood. Using an anatomically constrained magnetoencephalography approach, we examined event-related theta oscillations during a double-duty lexical decision task that combined demands on lexico-semantic processing and executive functions. Relative to typically developing peers, high-functioning adolescents with ASD had lower performance accuracy on trials engaging selective semantic retrieval and cognitive control. They showed an early overall theta increase in the left fusiform cortex followed by greater activity in the left-lateralized temporal (starting at ~250 ms) and frontal cortical areas (after ~450 ms) known to contribute to language processing. During response preparation and execution, the ASD group exhibited elevated theta in the anterior cingulate cortex, indicative of greater engagement of cognitive control. Simultaneously increased activity in the ipsilateral motor cortex may reflect a less lateralized and suboptimally organized motor circuitry. Spanning early sensory-specific and late response selection stages, the higher event-related theta responsivity in ASD may indicate compensatory recruitment to offset inefficient lexico-semantic retrieval under cognitively demanding conditions. Together, these findings provide further support for atypical language and executive functions in high-functioning ASD.

Altered Inferior Parietal Functional Connectivity is Correlated with Praxis and Social Skill Performance in Children with Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) have difficulties perceiving and producing skilled gestures, or praxis. The inferior parietal lobule (IPL) is crucial to praxis acquisition and expression, yet how IPL connectivity contributes to autism-associated impairments in praxis as well as social-communicative skill remains unclear. Using resting-state functional magnetic resonance imaging, we applied independent component analysis to test how IPL connectivity relates to praxis and social-communicative skills in children with and without ASD. Across all children (with/without ASD), praxis positively correlated with connectivity of left posterior-IPL with the left dorsal premotor cortex and with the bilateral posterior/medial parietal cortex. Praxis also correlated with connectivity of right central-IPL connectivity with the left intraparietal sulcus and medial parietal lobe. Further, in children with ASD, poorer praxis and social-communicative skills both correlated with weaker right central-IPL connectivity with the left cerebellum, posterior cingulate, and right dorsal premotor cortex. Our findings suggest that IPL connectivity is linked to praxis development, that contributions arise bilaterally, and that right IPL connectivity is associated with impaired praxis and social-communicative skills in autism. The findings underscore the potential impact of IPL connectivity and impaired skill acquisition on the development of a range of social-communicative and motor functions during childhood, including autism-associated impairments.

Unique deficit in embodied simulation in autism: An fMRI study comparing autism and developmental coordination disorder

A deficit in pre‐cognitively mirroring other people's actions and experiences may be related to the social impairments observed in autism spectrum disorder (ASD). However, it is unclear whether such embodied simulation deficits are unique to ASD or instead are related to motor impairment, which is commonly comorbid with ASD. Here we aim to disentangle how, neurologically, motor impairments contribute to simulation deficits and identify unique neural signatures of ASD. We compare children with ASD (N = 30) to children with Developmental Coordination Disorder (DCD; N = 23) as well as a typically developing group (N = 33) during fMRI tasks in which children observe, imitate, and mentalize about other people's actions. Results indicate a unique neural signature in ASD: during action observation, only the ASD group shows hypoactivity in a region important for simulation (inferior frontal gyrus, pars opercularis, IFGop). However, during a motor production task (imitation), the IFGop is hypoactive for both ASD and DCD groups. For all tasks, we find correlations across groups with motor ability, even after controlling for age, IQ, and social impairment. Conversely, across groups, mentalizing ability is correlated with activity in the dorsomedial prefrontal cortex when controlling for motor ability. These findings help identify the unique neurobiological basis of ASD for aspects of social processing. Furthermore, as no previous fMRI studies correlated brain activity with motor impairment in ASD, these findings help explain prior conflicting reports in these simulation networks.

The multiple process model of goal-directed aiming/reaching: insights on limb control from various special populations

Several years ago, our research group forwarded a model of goal-directed reaching and aiming that describes the processes involved in the optimization of speed, accuracy, and energy expenditure Elliott et al. (Psychol Bull 136:1023-1044, 2010). One of the main features of the model is the distinction between early impulse control, which is based on a comparison of expected to perceived sensory consequences, and late limb-target control that involves a spatial comparison of limb and target position. Our model also emphasizes the importance of strategic behaviors that limit the opportunity for worst-case or inefficient outcomes. In the 2010 paper, we included a section on how our model can be used to understand atypical aiming/reaching movements in a number of special populations. In light of a recent empirical and theoretical update of our model Elliott et al. (Neurosci Biobehav Rev 72:95-110, 2017), here we consider contemporary motor control work involving typical aging, Down syndrome, autism spectrum disorder, and tetraplegia with tendon-transfer surgery. We outline how atypical limb control can be viewed within the context of the multiple-process model of goal-directed reaching and aiming, and discuss the underlying perceptual-motor impairment that results in the adaptive solution developed by the specific group.

Perceptual category learning in autism spectrum disorder: Truth and consequences

The ability to categorize is fundamental to cognitive development. Some categories emerge effortlessly and rapidly while others can take years of experience to acquire. Children with autism spectrum disorder (ASD) are often able to name and sort objects, suggesting that their categorization abilities are largely intact. However, recent experimental work shows that the categories formed by individuals with ASD may diverge substantially from those that most people learn. This review considers how atypical perceptual category learning can affect cognitive development in children with ASD and how atypical categorization may contribute to many of the socially problematic symptoms associated with this disorder. Theoretical approaches to understanding perceptual processing and category learning at both the behavioral and neural levels are assessed in relation to known alterations in perceptual category learning associated with ASD. Mismatches between the ways in which children learn to organize perceived events relative to their peers and adults can accumulate over time, leading to difficulties in communication, social interactions, academic performance, and behavioral flexibility.

Predicting full-scale and verbal intelligence scores from functional Connectomic data in individuals with autism Spectrum disorder

Decoding how intelligence is engrained in the human brain construct is vital in the understanding of particular neurological disorders. While the majority of existing studies focus on characterizing intelligence in neurotypical (NT) brains, investigating how neural correlates of intelligence scores are altered by atypical neurodevelopmental disorders, such as Autism Spectrum Disorders (ASD), is almost absent. To help fill this gap, we use a connectome-based predictive model (CPM) to predict intelligence scores from functional connectome data, derived from resting-state functional magnetic resonance imaging (rsfMRI). The utilized model learns how to select the most significant positive and negative brain connections, independently, to predict the target intelligence scores in NT and ASD populations, respectively. In the first step, using leave-one-out cross-validation we train a linear regressor robust to outliers to identify functional brain connections that best predict the target intelligence score (p - value < 0.01). Next, for each training subject, positive (respectively negative) connections are summed to produce single-subject positive (respectively negative) summary values. These are then paired with the target training scores to train two linear regressors: (a) a positive model which maps each positive summary value to the subject score, and (b) a negative model which maps each negative summary value to the target score. In the testing stage, by selecting the same connections for the left-out testing subject, we compute their positive and negative summary values, which are then fed to the trained negative and positive models for predicting the target score. This framework was applied to NT and ASD populations independently to identify significant functional connections coding for full-scale and verbal intelligence quotients in the brain.

Children with Autism Spectrum Disorder Show Impairments During Dynamic Versus Static Grip-force Tracking

Impairments in visuomotor integration (VMI) may contribute to anomalous development of motor, as well as social-communicative, skills in children with autism spectrum disorder (ASD). However, it is relatively unknown whether VMI impairments are specific to children with ASD versus children with other neurodevelopmental disorders. As such, this study addressed the hypothesis that children with ASD, but not those in other clinical control groups, would show greater deficits in high-VMI dynamic grip-force tracking versus low-VMI static presentation. Seventy-nine children, aged 7-17 years, participated: 22 children with ASD, 17 children with fetal alcohol spectrum disorder (FASD), 18 children with Attention-Deficit Hyperactivity Disorder (ADHD), and 22 typically developing (TD) children. Two grip-force tracking conditions were examined: (1) a low-VMI condition (static visual target) and (2) a high-VMI condition (dynamic visual target). Low-frequency force oscillations <0.5 Hz during the visuomotor task were also examined. Two-way ANCOVAs were used to examine group x VMI and group x frequency effects (α = 0.05). Children with ASD showed a difficulty, above that seen in the ADHD/FASD groups, tracking dynamic, but not static, visual stimuli as compared to TD children. Low-frequency force oscillations <0.25 Hz were also significantly greater in the ASD versus the TD group. This study is the first to report VMI deficits during dynamic versus static grip-force tracking and increased proportion of force oscillations <0.25 Hz during visuomotor tracking in the ASD versus TD group. Dynamic VMI impairments may be a core psychophysiologic feature that could contribute to impaired development of motor and social-communicative skills in ASD. LAY SUMMARY: Children with autism spectrum disorder (ASD) show difficulties using dynamic visual stimuli to guide their own movements compared to their typically developing (TD) peers. It is unknown whether children without a diagnosis of ASD, but with other neurological disorders, show similar difficulties processing dynamic visual stimuli. In this study, we showed that children with ASD show a difficulty using dynamic, but not static, visual stimuli to guide movement that may explain atypical development of motor and social skills.

Learning of skilled movements via imitation in ASD

Autism spectrum disorder (ASD) consists of altered performance of a range of skills, including social/communicative and motor skills. It is unclear whether this altered performance results from atypical acquisition or learning of the skills or from atypical "online" performance of the skills. Atypicalities of skilled actions that require both motor and cognitive resources, such as abnormal gesturing, are highly prevalent in ASD and are easier to study in a laboratory context than are social/communicative skills. Imitation has long been known to be impaired in ASD; because learning via imitation is a prime method by which humans acquire skills, we tested the hypothesis that children with ASD show alterations in learning novel gestures via imitation. Eighteen participants with ASD and IQ > 80, ages 8-12.9 years, and 19 typically developing peers performed a task in which they watched a video of a model performing a novel, meaningless arm/hand gesture and copied the gesture. Each gesture video/copy sequence was repeated 4-6 times. Eight gestures were analyzed. Examination of learning trajectories revealed that while children with ASD made nearly as much progress in learning from repetition 1 to repetition 4, the shape of the learning curves differed. Causal modeling demonstrated the shape of the learning curve influenced both the performance of overlearned gestures and autism severity, suggesting that it is in the index of learning mechanisms relevant both to motor skills and to autism core features. Autism Res 2020, 13: 777-784.. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Imitation is a route by which humans learn a wide range of skills, naturally and in therapies. Imitation is known to be altered in autism spectrum disorder (ASD), but learning via imitation has not been rigorously examined. We found that the shape of the learning curve is altered in ASD, in a way that has a significant impact both on measures of autism severity and of other motor skills.

Accelerating Motor Skill Acquisition for Bicycle Riding in Children with ASD: A Pilot Study

Motor impairment is common in autism spectrum disorder (ASD) and, as such, a potential target for interventions to improve adaptive functioning. This study investigated motor skill acquisition in children with ASD (n = 15, 12 males; ages 7-16 years) during iCan Bike Camp, a 1-week, community-based intervention (5 × 75-min sessions) to teach independent bicycle riding. After completing the camp's task-oriented, individualized training program, all participants demonstrated motor skill acquisition on the bicycle, and nine participants rode independently at least 70 feet. Exploratory analyses showed that motor coordination and social communication correlated with rates of skill acquisition. These findings indicate the feasibility and efficacy of brief, community-based motor interventions to teach bicycle riding-an important developmental skill supporting adaptive functioning-to children with ASD.

Sex differences in brain structure: a twin study on restricted and repetitive behaviors in twin pairs with and without autism

Background

Females with autism spectrum disorder have been reported to exhibit fewer and less severe restricted and repetitive behaviors and interests compared to males. This difference might indicate sex-specific alterations of brain networks involved in autism symptom domains, especially within cortico-striatal and sensory integration networks. This study used a well-controlled twin design to examine sex differences in brain anatomy in relation to repetitive behaviors.

Methods

In 75 twin pairs (n = 150, 62 females, 88 males) enriched for autism spectrum disorder (n = 32), and other neurodevelopmental disorders (n = 32), we explored the association of restricted and repetitive behaviors and interests—operationalized by the Autism Diagnostic Interview-Revised (C domain) and the Social Responsiveness Scale-2 (Restricted Interests and Repetitive Behavior subscale)—with cortical volume, surface area and thickness of neocortical, sub-cortical, and cerebellar networks.

Results

Co-twin control analyses revealed within-pair associations between RRBI symptoms and increased thickness of the right intraparietal sulcus and reduced volume of the right orbital gyrus in females only, even though the mean number of RRBIs did not differ between the sexes. In a sub-sample of ASD-discordant pairs, increased thickness in association with RRBIs was found exclusively in females in the orbitofrontal regions, superior frontal gyrus, and intraparietal sulcus, while in males RRBIs tended to be associated with increased volume of the bilateral pallidum.

Limitations

However, due to a small sample size and the small difference in RRBI symptoms within pairs, the results of this exploratory study need to be interpreted with caution.

Conclusions

Our findings suggest that structural alterations of fronto-parietal networks in association with RRBIs are found mostly in females, while striatal networks are more affected in males. These results endorse the importance of investigating sex differences in the neurobiology of autism symptoms, and indicate different etiological pathways underlying restricted and repetitive behaviors and interests in females and males.

Prediction and Mismatch Negativity Responses Reflect Impairments in Action Semantic Processing in Adults With Autism Spectrum Disorders

The neurophysiological mechanisms underlying motor and language difficulties in autism spectrum disorders (ASD) are still largely unclear. The present work investigates biological indicators of sound processing, (action-) semantic understanding and predictive coding and their correlation with clinical symptoms of ASD. Twenty-two adults with high-functioning ASD and 25 typically developed (TD) participants engaged in an auditory, passive listening, Mismatch Negativity (MMN) task while high-density electroencephalography (EEG) was recorded. Action and non-action words were presented in the context of sounds, which were either semantically congruent with regard to the body part they relate to or semantically incongruent or unrelated. The anticipatory activity before sound onset, the Prediction Potential (PP), was significantly reduced in the ASD group specifically for action, but not for non-action sounds. The early-MMN-like responses to words (latency: 120 ms) were differentially modulated across groups: controls showed larger amplitudes for words in action-sound compared to non-action contexts, whereas ASD participants demonstrated enlarged early-MMN-like responses only in a pure tone context, with no other modulation dependent on action sound context. Late-MMN-like responses around 560 ms post-stimulus onset revealed body-part-congruent action-semantic priming for words in control participants, but not in the ASD group. Importantly, neurophysiological indices of semantic priming in ASD participants correlated with the extent of autistic traits as revealed by the Autism Spectrum Quotient (AQ). The data suggest that high-functioning adults with ASD show a specific deficit in semantic processing and predictive coding of sounds and words related to action, which is absent for neutral, non-action, sounds.

Motor Memory Deficits Contribute to Motor Impairments in Autism Spectrum Disorder

Sensorimotor abnormalities are common in individuals with autism spectrum disorder (ASD); however, the processes underlying these deficits remain unclear. This study examined force production with and without visual feedback to determine if individuals with ASD can utilize internal representations to guide sustained force. Individuals with ASD showed a faster rate of force decay in the absence of visual feedback. Comparison of force output and tests of social and verbal abilities demonstrated a link between motor memory impairment and social and verbal deficits in individuals with ASD. This finding suggests that deficits in storage or retrieval of motor memories contribute to sensorimotor deficits and implicates frontoparietal networks involved in short-term consolidation of action dynamics used to optimize ongoing motor output.

Deconstructing Diagnosis: Four Commentaries on a Diagnostic Tool to Assess Individuals for Autism Spectrum Disorders

Diagnostic assessment tools are widely used instruments in research and clinical practice to assess and evaluate autism symptoms for both children and adults. These tools typically involve observing the child or adult under assessment, and rating their behaviour for signs or so-called symptoms of autism. In order to examine how autism diagnosis is constructed, how diagnostic tools are positioned, and how their trainings are delivered, we paid for four places on a training course for a diagnostic tool. We asked the attendees (the first four authors) to each produce a critical commentary about their impressions of the training and the diagnostic tool itself. Their commentaries are published here in full. They have various disciplinary backgrounds: one is a social scientist, one an ethicist, one a psychiatrist, and one a developmental psychologist. The commentaries are followed by a concluding section that summarises the themes, commonalities, and differences between their accounts of the training course. Authors differed as to whether the diagnostic tool is a useful and necessary endeavour. Nevertheless, all critiqued of the tool's lack of transparency, recognizing context, emotion, and differences in interpretation and power imbalances as playing an unidentified role in the assessment process. Based on this project, we recommend that training for raters for such tools should be accessible to a wider group of people, and incorporate more explicit recognition of its own limitations and commercialisation.

Epilepsy and Autism Severity: A Study of 6,975 Children

Epilepsy is known to occur in a higher-than-expected proportion of individuals with autism spectrum disorders (ASDs). Prior studies of this heterogeneous disorder have suggested that intelligence quotient (IQ) may drive this relationship. Because intellectual disability (ID) is, independently of ASD, a risk factor for epilepsy, current literature calls into question the long-understood unique relationship between ASD and epilepsy. Second, data have been unclear about whether developmental regression in ASD is associated with epilepsy. Using two cohorts from an online research registry, totaling 6,975 children with ASD, we examined the independent role of four ASD severity measures in driving the relationship with epilepsy: ID, language impairment, core ASD symptom severity, and motor dysfunction, controlling for two known relevant factors: age and sex. We also examined whether developmental regression and epilepsy have an independent statistical link. All four ASD severity factors showed independent statistical associations with epilepsy in one cohort, and three in the other. ID showed the largest relative risk (RR) in both cohorts. Effect sizes were modest. Regression similarly showed an independent statistical association with epilepsy, but with small effect size. Similar to previous work, ID showed the greatest contribution to RR for epilepsy among children with ASD. However, other ASD severity markers showed statistical associations, demonstrating that the ASD-epilepsy association is not reducible to the effect of ID. Inconsistencies in the literature may be due to underpowered studies, yet moving forward with larger-n studies, clinical significance and scientific relevance may be dictated by effect size and not merely statistical significance. Autism Res 2019, 12: 1251-1259. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Epilepsy is known to occur more often in individuals with autism spectrum disorders (ASDs) than is the case in the general population. The association between ASD and epilepsy is of interest because studying the two disorders in combination may help advance our understanding of genetic, molecular, and cellular mechanisms-as well as therapies-for both. Recent studies have suggested that intelligence quotient (IQ) alone in individuals with ASD may account for the increased prevalence of epilepsy. However, our approach was to look at a range of severity factors relevant to ASD and to look for correlations between each severity factor and epilepsy, within two large samples of children with ASD. In summary, we found that each severity factor-presence of intellectual disability, presence of language atypicalities, ASD-specific symptoms severity, and presence of motor issues-independently predicted a small increased risk for epilepsy, countering the argument that IQ alone is a risk factor. We also examined whether epilepsy is associated with developmental regression. Although severe epilepsy syndromes such as Landau-Kleffner syndrome are known to cause autistic-like symptoms following developmental regression, there is controversy about whether other forms of epilepsy are associated with the more common developmental regression seen in many young children with epilepsy. Indeed, we found a small association between epilepsy and developmental regression.

Reframing schizophrenia and autism as bodily self-consciousness disorders leading to a deficit of theory of mind and empathy with social communication impairments

Prior observations and studies suggest self-consciousness disorders in schizophrenia and Autism Spectrum Disorder (ASD), two neurodevelopmental disorders sharing social communication impairments. First, the relationships between schizophrenia and autism are explored regarding social communication impairments. Then, self-consciousness disorders in schizophrenia and autism are described and discussed in relation with impairments of body self leading to impairments of self-other differentiation, a deficit of theory of mind and empathy, and their consequences on social communication. Also, neurological dysfunction involved possibly in self-consciousness disorders in schizophrenia and autism is presented. In conclusion, a new model is proposed integrating results of studies presented here and stating the existence of bodily self-consciousness disorders in schizophrenia and autism associated with altered/absent intermodal sensory integration (especially visual-kinesthetic-tactile integration). This would result in problems of self-other differentiation, leading in turn to a deficit of theory of mind and empathy as well as social communication impairments. This model opens new perspectives to understand better self-consciousness disorders and social communication impairments in schizophrenia and ASD and to develop therapeutic strategies.

Alterations in white matter microstructure and regional volume are related to motor functions in boys with autism spectrum disorder

BACKGROUND

Altered inter-regional structural connectivity related to higher cognitive functions has been commonly reported in individuals with autism spectrum disorder (ASD). However, whether these alterations similarly involve cortico-cerebellar motor circuitries remains largely elusive.

METHODS

Using a cross-modality approach accounting for in-scanner motion levels, we investigated white matter (WM) properties in motor circuits of 55 boys with ASD (aged 8-18 years) and 68 age-matched typically developing boys. Regional WM volumes in the primary motor, supplementary motor, somatosensory, and cerebellar areas were investigated using voxel-based morphometry. Diffusion spectrum imaging tractography was used to estimate WM integrity of the corticospinal, cortico-ponto-cerebellar (including fronto-ponto-cerebellar and parieto-ponto-cerebellar), and dentato-rubro-thalamo-cortical tracts. The reaction time test in the Cambridge Neuropsychological Test Automated Battery was used to assess motor performances.

RESULTS

Boys with ASD had shorter movement time, increased WM volumes in the left somatosensory area, but decreased generalized fractional anisotropy value in the left parieto-ponto-cerebellar tract, compared to controls. A positive correlation between movement time and microstructural properties of the left parieto-ponto-cerebellar tract was found in boys with ASD.

CONCLUSIONS

As the first study to demonstrate altered WM properties in the left somatosensory area, and its descending pathway connecting to the cerebellum in ASD, current results may highlight a potential new target of interventions for motor performance in ASD.

The Impact of Different Movement Types on Motor Planning and Execution in Individuals With Autism Spectrum Disorder

Although there are consistent reports that motor skills are affected in individuals with autism, the details are still debated; specifically, why individuals spend more time preparing movements and whether or not movement execution takes longer. The present study investigated if the conflicting reports were related to: (a) differences in movement type and (b) if longer reaction times were related to the time for motor planning or for force-generation processes. Participants performed three different movement types. People with autism had longer premotor reaction times and movement times for the three-dimensional movements only. We suggest individuals with autism have difficulty planning and executing unconstrained reaching movements specifically. The present results are consistent with evidence that autistic individuals have more difficulty effectively using visual feedback but can use tactile feedback to execute reaching movements efficiently and accurately.

Bimanual Reach to Grasp Movements in Youth With and Without Autism Spectrum Disorder

Reaching and grasping (prehension) is one of the earliest developing motor skills in humans, but continued prehension development in childhood and adolescence enables the performance of increasingly complex manual tasks. In individuals with autism spectrum disorder (ASD) atypical unimanual reaching and grasping has been reported, but to date, no studies have investigated discrete bimanual movements. We examined unimanual and bimanual reach to grasp tasks in youth with ASD to better understand how motor performance might change with increasing complexity. Twenty youth with ASD (10.1 ± 2.4 years) and 17 youth with typical development (TD) (9.6 ± 2.6 years) were instructed to reach and grasp cubes that became illuminated. Participants were asked to reach out with the right and/or left hands to grasp and lift targets located at near (18 cm) and/or far (28 cm) distances. For the unimanual (simplest) condition, participants grasped one illuminated cube (with either the left or right hand). For the bimanual conditions, participants grasped two illuminated cubes located at the same distance from the start position (bimanual symmetric condition) or two illuminated cubes located at different distances (bimanual asymmetric condition). Significant interactions among diagnostic group, task complexity, and age were found for initiation time (IT) and movement time (MT). Specifically, the older children in both groups initiated and performed their movements faster in the unimanual condition than in the bimanual conditions, although the older children with ASD produced slower ITs and MTs compared to typically developing peers across all three conditions. Surprisingly, the younger children with ASD had similar ITs and MTs as their peers for the unimanual condition but did not considerably slow these times to adjust for the complexity of the bimanual tasks. We hypothesize that they chose to re-use the motor plans that were generated for the unimanual trials rather than generate more appropriate motor plans for the bimanual tasks. An atypical spatiotemporal relationship between MT and peak aperture (PA) was also found in the ASD group. Together, our results suggest deficits in motor planning that result in subtle effects on performance in younger children with ASD that become more pronounced with age.

The reach-to-grasp movement in infants later diagnosed with autism spectrum disorder: a high-risk sibling cohort study

BACKGROUND

Although autism spectrum disorder (ASD) is characterized by impairments in social communication and the presence of repetitive behavior and/or restricted interests, there is evidence that motor impairments may be a contributing factor to the ASD phenotype. The purpose of this study was to examine the motor act of reaching-to-grasp in children at high risk (HR; with an older sibling diagnosed with ASD) and low-risk (LR; no family history of ASD) for ASD.

METHODS

Children were compared for differences in reaching-to-grasp based on sibling status and diagnostic outcome. Children were enrolled between 6 and 12 months of age and the reach-to-grasp movement was scored at 6, 9, (where available) 12, 15, 18, 24, and 36 months of age using the qualitative Skilled Reaching Rating Scale to determine the presence of any group-, age-, or sex-related differences in the mechanics of the reach-to-grasp movement using a Mixed Models analysis. At 36 months, all children underwent a gold-standard diagnostic assessment, which resulted in three outcome groups: HR children diagnosed with ASD (HR-ASD; n = 10), HR children not diagnosed with ASD (HR-N; n = 10), and low-risk children not diagnosed with ASD (LR; n = 10).

RESULTS

The group of children who were later diagnosed with ASD (HR-ASD group) showed higher (worse) total scores on the reach-to-grasp movement, as well as higher scores on the components of Orient, Lift, and Pronate compared to children in the LR and HR-N groups.

CONCLUSIONS

Our results support the growing literature indicating that children who are later diagnosed with ASD show impaired early motor performance. These results highlight the importance of early surveillance of children who are at elevated risk for ASD, and early initiatives should focus on early signs of the phenotype, including both movement and sensory differences (prodromal signs) prior to the emergence of diagnostic characteristics.

Exploring Visual Perspective Taking and body awareness in children with Autism Spectrum Disorder

INTRODUCTION

Recent evidence suggests that impairments in social cognition are associated to the cognitive abilities needed to take several viewpoints in perceptual situations and body awareness. The aim of the current study was to investigate Visual Perspective Taking (VPT) and Body awareness performance in a group of children with Autism Spectrum Disorders (ASD) compared with a group of children with Intellectual Disability (ID) and typically developing (TD) children.

METHODS

Our groups were administered an IQ test and a VPT task, and body awareness tests.

RESULTS

Children with ASD or ID were more impaired in body awareness development compared to TD (p < .001) children. The ASD group differentiates largely from the other two groups in the mean VPT (p < .001) scores.

CONCLUSIONS

The current study provides a framework for considering social impairments in autism on a broader scale, including visuoperceptual and body awareness difficulties as a core contributor to social interaction difficulties.

Altered task-related modulation of long-range connectivity in children with autism

Functional connectivity differences between children with autism spectrum disorder (ASD) and typically developing children have been described in multiple datasets. However, few studies examine the task-related changes in connectivity in disorder-relevant behavioral paradigms. In this paper, we examined the task-related changes in functional connectivity using EEG and a movement-based paradigm that has behavioral relevance to ASD. Resting-state studies motivated our hypothesis that children with ASD would show a decreased magnitude of functional connectivity during the performance of a motor-control task. Contrary to our initial hypothesis, however, we observed that task-related modulation of functional connectivity in children with ASD was in the direction opposite to that of TDs. The task-related connectivity changes were correlated with clinical symptom scores. Our results suggest that children with ASD may have differences in cortical segregation/integration during the performance of a task, and that part of the differences in connectivity modulation may serve as a compensatory mechanism. Autism Res 2018, 11: 245-257. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Decreased connectivity between brain regions is thought to cause the symptoms of autism. Because most of our knowledge comes from data in which children are at rest, we do not know how connectivity changes directly lead to autistic behaviors, such as impaired gestures. When typically developing children produced complex movements, connectivity decreased between brain regions. In children with autism, connectivity increased. It may be that behavior-related changes in brain connectivity are more important than absolute differences in connectivity in autism.

Standing Postural Control in Individuals with Autism Spectrum Disorder: Systematic Review and Meta-analysis

Impairments in postural control affect the development of motor and social skills in individuals with autism spectrum disorder (ASD). This review compared the effect of different sensory conditions on static standing postural control between ASD and neurotypical individuals. Results from 19 studies indicated a large difference in postural control between groups across all sensory conditions. This review revealed sensorimotor and multiple sensory processing deficits in ASD. The tendency for individuals with ASD to be more susceptible to postural instability with use of visual information compared with somatosensory information suggests perinatal alterations in sensory development. There is further scope for studies on the use of sensory information and postural control to provide additional evidence about sensorimotor processing in ASD.

Comparing motor performance, praxis, coordination, and interpersonal synchrony between children with and without Autism Spectrum Disorder (ASD)

Children with Autism Spectrum Disorder (ASD) have basic motor impairments in balance, gait, and coordination as well as autism-specific impairments in praxis/motor planning and interpersonal synchrony. Majority of the current literature focuses on isolated motor behaviors or domains. Additionally, the relationship between cognition, symptom severity, and motor performance in ASD is unclear. We used a comprehensive set of measures to compare gross and fine motor, praxis/imitation, motor coordination, and interpersonal synchrony skills across three groups of children between 5 and 12 years of age: children with ASD with high IQ (HASD), children with ASD with low IQ (LASD), and typically developing (TD) children. We used the Bruininks-Oseretsky Test of Motor Proficiency and the Bilateral Motor Coordination subtest of the Sensory Integration and Praxis Tests to assess motor performance and praxis skills respectively. Children were also examined while performing simple and complex rhythmic upper and lower limb actions on their own (solo context) and with a social partner (social context). Both ASD groups had lower gross and fine motor scores, greater praxis errors in total and within various error types, lower movement rates, greater movement variability, and weaker interpersonal synchrony compared to the TD group. In addition, the LASD group had lower gross motor scores and greater mirroring errors compared to the HASD group. Overall, a variety of motor impairments are present across the entire spectrum of children with ASD, regardless of their IQ scores. Both, fine and gross motor performance significantly correlated with IQ but not with autism severity; however, praxis errors (mainly, total, overflow, and rhythmicity) strongly correlated with autism severity and not IQ. Our study findings highlight the need for clinicians and therapists to include motor evaluations and interventions in the standard-of-care of children with ASD and for the broader autism community to recognize dyspraxia as an integral part of the definition of ASD.

Motor learning characterization in people with autism spectrum disorder: A systematic review

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder primarily characterized by deficits in social interaction, communication and implicit skill learning.

Globally weaker and topologically different: resting-state connectivity in youth with autism

Background

There is a lack of agreement about functional connectivity differences in individuals with autism spectrum disorder (ASD). Studies using absolute strength have found reduced connectivity, while those using relative strength––a measure of system topology––reveal mostly enhanced connectivity. We hypothesized that mixed findings may be driven by the metric of functional connectivity.

Methods

Resting-state echo planar 3 T functional magnetic resonance imaging scans were acquired on a Siemens Verio Scanner from 6 to 17-year-old youth with ASD (n = 81) and a matched typically developing control group (n = 82). All functional time series data were preprocessed using a confound regression procedure that has been previously validated in large-scale developmental datasets. It has also been shown to be highly effective at reducing the influence of motion artifact on connectivity data. We extracted time series data from a 333-node parcellation scheme, which was previously mapped to 13 functional systems. A Pearson’s correlation was calculated and transformed to Fisher’s z between every pair of nodes to create a weighted 333 × 333 adjacency matrix. Mean absolute functional connectivity strength was the mean Fisher’s z of the matrix. Relative functional connectivity was corrected for individual differences in mean absolute functional connectivity (i.e., each connection in the matrix was divided by their mean z), and functional connectivity was evaluated within and across each of the functional networks in the parcellation scheme.

Results

Absolute functional connectivity strength was lower in ASD, and lower functional connectivity was correlated with greater ASD symptom severity. Relative functional connectivity was higher for the ASD group in the ventral attention and retrosplenial-temporal systems, with lower cross-system functional connectivity between the ventral attention and somatomotor-mouth systems. Functional connectivity within the ventral attention and retro-splenial systems correlated significantly with ASD symptom severity.

Conclusions

Within a context of globally weaker functional connectivity, youth with ASD have an atypical topology of brain systems that support social perception and communication. This study clarifies the mixed results reported previously and demonstrates that the functional connectivity metric influences the observed direction of functional connectivity differences for individuals with ASD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13229-017-0156-6) contains supplementary material, which is available to authorized users.