Reaching and grasping in autism spectrum disorder: a review of recent literature

The Gestalt of functioning in autism revisited: First revision of the International Classification of Functioning, Disability and Health Core Sets

LAY ABSTRACT

Autistic people experience individual strengths and challenges as well as barriers and facilitators in their environment. All of these factors contribute to how well autistic people can cope in everyday life, fulfill the roles they choose, and meet their needs. The World Health Organization has developed a system aiming to capture the many factors within people (like how someone thinks and feels) and outside of people (things around a person) that influence their daily living, called the International Classification of Functioning, Disability and Health. The International Classification of Functioning, Disability and Health can be used for different purposes in research and practice to assess people's situations and plan support measures. Previously in 2019, the International Classification of Functioning, Disability and Health was adapted to autism by developing so-called Core Sets, which are shorter International Classification of Functioning, Disability and Health versions for use in specific conditions. Here, we present the first revisions of the International Classification of Functioning, Disability and Health Core Sets for autism, based on research, development results, and community feedback. Some factors influencing daily life for autistic people were added to the Core Sets, and other factors deemed less relevant were removed. Changes were also made in Core Sets designed for different age groups (0-5, 6-16, and ⩾17 years). Particularly, contents for sensory processing (like smell, touch, seeing, hearing) were added. We recommend these updated Core Sets for future use in autism research and practice. These changes to the Core Sets after 4 years indicate that there should be ongoing updates based on research and experience from practice and involvement of stakeholders.

Research progress of neuron-specific enolase in cognitive disorder: a mini review

Numerous studies have demonstrated that neuron-specific enolase (NSE) serves as a distinctive indicator of neuronal injury, with its concentration in blood reflecting the extent and magnitude of nervous system damage, and the expression of serum NSE is correlated with cognitive dysfunction. The assessment of NSE holds significant importance in diagnosing cognitive dysfunction, assessing disease severity, predicting prognosis, and guiding treatment. In this review, the research progress of NSE in cognitive dysfunction was reviewed, and the value of serum NSE level in predicting disease severity and prognosis of patients with cognitive dysfunction was discussed.

Motor Impairments in Children with Autism Spectrum Disorder: A Systematic Review and Meta-analysis

This article comprehensively reviews motor impairments in children with autism spectrum disorder (ASD) to: (1) determine the prevalence of motor problems in children with ASD; (2) understand the nature of motor difficulties in ASD and whether they are consistent with developmental coordination disorder (DCD); and (3) determine if the term DCD was used as a co-occurring diagnosis in children with ASD after publication of the DSM-5 in 2013. The following databases were systematically searched: MEDLINE, EMBASE, CINAHL, and PsycINFO from 2010 to December 2021. Articles were included if they: (1) were peer-reviewed and published in a scientific journal; (2) included children with ASD who were between 5 and 12 years; (3) used motor or function measures to assess motor abilities in children with ASD. Studies that included children with intellectual disabilities were excluded. Two independent reviewers reviewed titles, abstracts, and full-text articles for inclusion. Twenty-seven studies met the inclusion criteria and were assessed for quality by two independent reviewers using the Appraisal tool for Cross-Sectional Studies. The majority of articles (92.5%) indicated that 50-88% of children with ASD had significant motor impairments on standardized motor assessments and/or functional questionnaires. The nature of motor and function problems in ASD were consistent with DCD; however, only three out of 20 papers (15%) that were published from 2014 described the motor problems as DCD. One study reported that 15.1% of children with ASD with motor impairments had a co-occurring diagnosis of DCD, suggesting that DCD is under-recognized in this clinical population.

Fine Motor Skills, a Surrogate of Motor Planning Ability, at Age 2 Predict Social Skills at Age 6

OBJECTIVES

Motor planning is the cognitive process of planning necessary steps for achieving a purposeful movement and is specifically reflected through object manipulation. This study aimed to investigate whether fine motor skills, a surrogate of the motor planning ability of object manipulation, in early childhood are associated with later social skills, in a general-population birth cohort.

METHODS

A total of 913 children, participating in the Hamamatsu Birth Cohort for Mothers and Children, were enrolled. Social skills were measured using the Vineland Adaptive Behavior Scales-II, Socialization domain, at age 6 years. Fine motor skills were measured using the Mullen Scales of Early Learning at 14, 24, and 32 months. The associations between fine motor skills at ages 14, 24, and 32 months and social skills at age 6 years were tested separately through multivariable linear regression after adjusting for covariates, including gross motor and language skills at the contemporaneous age, autistic symptoms at age 6 years, and demographic factors.

RESULTS

Fine motor skills at 24 and 32 months were significantly associated with social skills at age 6 years (at 24 months: nonstandardized regression coefficient = 1.38 [95% CI, 0.50-2.26], p = 0.002; at 32 months: 1.47 [0.56-2.38], p = 0.001).

CONCLUSION

Fine motor skills in early childhood predicted social skills at age 6 years, indicating an association between the complex motor planning ability of object manipulation and later social skills. Children who demonstrate fine motor delay at as early an age as 2 years should be closely monitored by child professionals.

Perinatal exposure to the immune-suppressant di-n-octyltin dichloride affects brain development in rats

Disruption of the immune system during embryonic brain development by environmental chemicals was proposed as a possible cause of neurodevelopmental disorders. We previously found adverse effects of di-n-octyltin dichloride (DOTC) on maternal and developing immune systems of rats in an extended one-generation reproductive toxicity study according to the OECD 443 test guideline. We hypothesize that the DOTC-induced changes in the immune system can affect neurodevelopment. Therefore, we used in-vivo MRI and PET imaging and genomics, in addition to behavioral testing and neuropathology as proposed in OECD test guideline 443, to investigate the effect of DOTC on structural and functional brain development. Male rats were exposed to DOTC (0, 3, 10, or 30 mg/kg of diet) from 2 weeks prior to mating of the F0-generation until sacrifice of F1-animals. The brains of rats, exposed to DOTC showed a transiently enlarged volume of specific brain regions (MRI), altered specific gravity, and transient hyper-metabolism ([18F]FDG PET). The alterations in brain development concurred with hyper-responsiveness in auditory startle response and slight hyperactivity in young adult animals. Genomics identified altered transcription of key regulators involved in neurodevelopment and neural function (e.g. Nrgrn, Shank3, Igf1r, Cck, Apba2, Foxp2); and regulators involved in cell size, cell proliferation, and organ development, especially immune system development and functioning (e.g. LOC679869, Itga11, Arhgap5, Cd47, Dlg1, Gas6, Cml5, Mef2c). The results suggest the involvement of immunotoxicity in the impairment of the nervous system by DOTC and support the hypothesis of a close connection between the immune and nervous systems in brain development.

A clinical 3D pointing test differentiates spatial memory deficits in dementia and bilateral vestibular failure

BACKGROUND

Deficits in spatial memory, orientation, and navigation are often neglected early signs of cognitive impairment or loss of vestibular function. Real-world navigation tests require complex setups. In contrast, simple pointing at targets in a three-dimensional environment is a basic sensorimotor ability which provides an alternative measure of spatial orientation and memory at bedside. The aim of this study was to test the reliability of a previously established 3D-Real-World Pointing Test (3D-RWPT) in patients with cognitive impairment due to different neurodegenerative disorders, bilateral vestibulopathy, or a combination of both compared to healthy participants.

METHODS

The 3D-RWPT was performed using a static array of targets in front of the seated participant before and, as a transformation task, after a 90-degree body rotation around the yaw-axis. Three groups of patients were enrolled: (1) chronic bilateral vestibulopathy (BVP) with normal cognition (n = 32), (2) cognitive impairment with normal vestibular function (n = 28), and (3) combined BVP and cognitive impairment (n = 9). The control group consisted of age-matched participants (HP) without cognitive and vestibular deficits (n = 67). Analyses focused on paradigm-specific mean angular deviation of pointing in the azimuth (horizontal) and polar (vertical) spatial planes, of the preferred pointing strategy (egocentric or allocentric), and the resulting shape configuration of the pointing array relative to the stimulus array. Statistical analysis was performed using age-corrected ANCOVA-testing with Bonferroni correction and correlation analysis using Spearman's rho.

RESULTS

Patients with cognitive impairment employed more egocentric pointing strategies while patients with BVP but normal cognition and HP used more world-based solutions (pBonf 5.78 × 10-3**). Differences in pointing accuracy were only found in the azimuth plane, unveiling unique patterns where patients with cognitive impairment showed decreased accuracy in the transformation tasks of the 3D-RWPT (pBonf < 0.001***) while patients with BVP struggled in the post-rotation tasks (pBonf < 0.001***). Overall azimuth pointing performance was still adequate in some patients with BVP but significantly decreased when combined with a cognitive deficit.

CONCLUSION

The 3D-RWPT provides a simple and fast measure of spatial orientation and memory. Cognitive impairment often led to a shift from world-based allocentric pointing strategy to an egocentric performance with less azimuth accuracy compared to age-matched controls. This supports the view that cognitive deficits hinder the mental buildup of the stimulus pattern represented as a geometrical form. Vestibular hypofunction negatively affected spatial memory and pointing performance in the azimuth plane. The most severe spatial impairments (angular deviation, figure frame configuration) were found in patients with combined cognitive and vestibular deficits.

Motor imagery in autism: a systematic review

Introduction

Motor Imagery (MI) is when an individual imagines performing an action without physically executing that action and is thought to involve similar neural processes used for execution of physical movement. As motor coordination difficulties are common in autistic individuals it is possible that these may affect MI ability. The aim of this systematic review was to assess the current knowledge around MI ability in autistic individuals.

Methods

A systematic search was conducted for articles published before September 2023, following PRISMA guidance. Search engines were PsycINFO, PubMed, Web of Science, Scopus, Wiley Online Library and PsyArXiv. Inclusion criteria included: (a) Original peer-reviewed and pre-print publications; (b) Autistic and a non-autistic group (c) Implicit or explicit imagery tasks (d) Behavioral, neurophysiological or self-rating measures, (e) Written in the English language. Exclusion criteria were (a) Articles only about MI or autism (b) Articles where the autism data is not presented separately (c) Articles on action observation, recognition or imitation only (d) Review articles. A narrative synthesis of the evidence was conducted.

Results

Sixteen studies across fourteen articles were included. Tasks were divided into implicit (unconscious) or explicit (conscious) MI. The implicit tasks used either hand (6) or body (4) rotation tasks. Explicit tasks consisted of perspective taking tasks (3), a questionnaire (1) and explicit instructions to imagine performing a movement (2). A MI strategy was apparent for the hand rotation task in autistic children, although may have been more challenging. Evidence was mixed and inconclusive for the remaining task types due to the varied range of different tasks and, measures conducted and design limitations. Further limitations included a sex bias toward males and the hand rotation task only being conducted in children.

Discussion

There is currently an incomplete understanding of MI ability in autistic individuals. The field would benefit from a battery of fully described implicit and explicit MI tasks, conducted across the same groups of autistic children and adults. Improved knowledge around MI in autistic individuals is important for understanding whether MI techniques may benefit motor coordination in some autistic people.

The Effects of an Inclusive Badminton Program on Static Postural Control for Individuals with Intellectual and Developmental Disabilities

The purpose of the study was to examine static postural control/balance in young adults with intellectual and developmental disabilities (IDD) and typically developing (TD) young adults before, during, and after an inclusive badminton intervention. Eight participants (four IDD-BADM and four TD-BADM) participated in a 12-week inclusive badminton intervention, with the other eight participants as matched controls (four IDD-CONTR and four TD-CONTR) (74.19 kg ± 9.8 kg, 171.96 cm ± 5.4 cm; 21.7 ± 1.8 years of age; nine females and seven males; eight with IDD and eight TD). The study followed a repeated measures design (pre, mid, post) before the intervention, at 6 weeks, and after 12 weeks. Static postural sway conditions included: bilateral stance eyes open (20 s), eyes closed (10 s), foam eyes open (20 s), foam eyes closed (10 s), and unilateral stance eyes open (10 s) and foam eyes open (10 s). Sway measurements included: average anterior/posterior (A/P) displacement (in), average medial/lateral (M/L) displacement (in), average 95% ellipsoid area (in2), and average velocity (ft/s). Significant time × group interactions were reported for average velocity (EO) (p = 0.030), average length (EO) (p = 0.030), 95% ellipsoid area (EO) (p = 0.049), and average A/P displacement (1LEO) (p = 0.036) for IDD-BADM. Significant time main effects were reported for average A/P displacement (FEO) (p = 0.040) for IDD groups. Significant time main effects were reported for average M/L displacement (EO) (p = 0.001), (EC) (p = 0.004), (FEO) (p = 0.005), (FEC) (p = 0.004), and average A/P displacement (EO) (p = 0.006) and (FEO) (p = 0.005) for TD groups. An inclusive badminton program indicated evidence of improved static postural control for those with IDD. However, no significant differences were reported for TD peers.

Motor deficits in autism differ from that of developmental coordination disorder

LAY ABSTRACT

A vast majority of individuals with autism spectrum disorder experience impairments in motor skills. Those are often labelled as additional developmental coordination disorder despite the lack of studies comparing both disorders. Consequently, motor skills rehabilitation programmes in autism are often not specific but rather consist in standard programmes for developmental coordination disorder. Here, we compared motor performance in three groups of children: a control group, an autism spectrum disorder group and a developmental coordination disorder group. Despite similar level of motor skills evaluated by the standard movement assessment battery for children, in a Reach-to-Displace Task, children with autism spectrum disorder and developmental coordination disorder showed specific motor control deficits. Children with autism spectrum disorder failed to anticipate the object properties, but could correct their movement as well as typically developing children. In contrast, children with developmental coordination disorder were atypically slow, but showed a spared anticipation. Our study has important clinical implications as motor skills rehabilitations are crucial to both populations. Specifically, our findings suggest that individuals with autism spectrum disorder would benefit from therapies aiming at improving their anticipation, maybe through the support of their preserved representations and use of sensory information. Conversely, individuals with developmental coordination disorder would benefit from a focus on the use of sensory information in a timely fashion.

Associations Between Coordination and Wearable Sensor Variables Vary by Recording Context but Not Assessment Type

Motor coordination is an important driver of development and improved coordination assessments could facilitate better screening, diagnosis, and intervention for children at risk of developmental disorders. Wearable sensors could provide data that enhance the characterization of coordination and the clinical utility of that data may vary depending on how sensor variables from different recording contexts relate to coordination. We used wearable sensors at the wrists to capture upper-limb movement in 85 children aged 6-12. Sensor variables were extracted from two recording contexts. Structured recordings occurred in the lab during a unilateral throwing task. Unstructured recordings occurred during free-living activity. The objective was to determine the influence of recording context (unstructured versus structured) and assessment type (direct vs. indirect) on the association between sensor variables and coordination. The greatest associations were between six sensor variables from the structured context and the direct measure of coordination. Worse coordination scores were associated with upper-limb movements that had higher peak magnitudes, greater variance, and less smoothness. The associations were consistent across both arms, even though the structured task was unilateral. This finding suggests that wearable sensors could be paired with a simple, structured task to yield clinically informative variables that relate to motor coordination.

From "one big clumsy mess" to "a fundamental part of my character." Autistic adults' experiences of motor coordination

Altered motor coordination is common in autistic individuals affecting a range of movements such as manual dexterity, eye-hand coordination, balance and gait. However, motor coordination is not routinely assessed leading to undiagnosed and untreated motor coordination difficulties, particularly in adults. Few studies have investigated motor coordination difficulties and their impact from the viewpoint of autistic people. Therefore, the current study used FGs and thematic analysis to document the experience of motor coordination difficulties from the viewpoint of 17 autistic adults. Four main themes were identified. First, motor coordination difficulties were pervasive and variable, being present life-long and within multiple movements and affecting many aspects of life. Furthermore, the nature of the difficulties was variable within and between participants along with differing awareness of coordination ability. Second, participants described motor coordination as an active process, requiring concentration for most actions and at a level seemingly greater than other people. Third, motor coordination difficulties impacted upon social and emotional wellbeing by placing strain on relationships, prompting bullying and exclusion, putting safety at risk and causing a range of negative emotions. Fourth, in the absence of any support, participants described multiple learning and coping strategies. Findings highlight how it is essential to address the current lack of support for motor coordination considering the significant social and emotional consequences described by our participants. Further investigation of motor learning and interactions between sensory and motor performance in autistic adults is also warranted.

Toddlers at Elevated Likelihood for Autism: Exploring Sensory and Language Treatment Predictors

Baseline child characteristics may predict treatment outcomes in children with or at elevated likelihood of developing autism (EL-ASD). Little is known about the role of child sensory and language features on treatment outcome. Participants were randomly assigned to a parent-mediated intervention or control condition. Analyses explored the relationship between baseline child sensory and language characteristics and changes in ASD symptoms over approximately 9 months. Higher baseline sensory hyporeactivity was significantly related to less improvement in social communication (SC) for the treatment group only. More baseline atypical vocalizations were significantly related to less improvement on SC across treatment and control groups. This work provides an initial framework to encourage the tailoring of interventions for EL-ASD children, suggesting sensory reactivity and atypical vocalizations may be useful behaviors to consider in treatment planning.

Hand-foot coordination is significantly influenced by motion direction in individuals with autism spectrum disorder

Generally, when individuals attempt to move two limbs rhythmically in the opposite direction (e.g., flex the left hand and extend the left foot along the sagittal plane), the movements tend to be instead performed in the same direction. This phenomenon, known as directional constraint, can be harnessed to examine the difficulties in movement coordination exhibited by most individuals with autism spectrum disorder (ASD). While such difficulties have already been investigated through standardized clinical assessments, they have not been examined through kinematic methods. Thus, we employed a clinical assessment scale in an experimentally controlled environment to investigate whether stronger directional constraint during the rhythmic movement of two limbs is more pronounced and associated with decreased movement coordination in individuals with ASD. ASD and typically developing (TD) participants were asked to rhythmically move two limbs either in the same or opposite directions. In addition, the coordination skills of participants were assessed using the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2). Subjects with ASD showed significantly stronger directional constraint than TD participants during the contralateral and ipsilateral movement of the hand and foot. According to the pooled data from both groups, participants who showed stronger directional constraint during these two movement conditions also exhibited poorer coordinated movement skills in the BOT-2. These results suggest that people with ASD may have difficulties in inhibiting the neural signals that synchronize the direction of inter-limb movements, thus resulting in coordination disabilities. LAY SUMMARY: Individuals with autism spectrum disorder (ASD) often exhibit difficulties in coordinated movements. We asked those with ASD and typically developing (TD) participants to move two limbs (e.g., left hand and left foot) either in the same or the opposite direction. Results demonstrated that participants with ASD had more difficulties in counteracting the tendency of their hand and foot to synchronously move in the same direction. Our findings suggested that difficulties to suppress synchronized movements of the hand and foot result in coordination disabilities.

Emerging signs of autism spectrum disorder in infancy: Putative neural substrate

Autism spectrum disorder (ASD) is characterized by altered development of the social brain with prominent atypical features in the fronto-temporo-parietal cortex and cerebellum. Early signs of ASD emerge between 6 and 12 months: reduced social communication, slightly less advanced motor development, and repetitive behaviour. The fronto-temporo-parietal cortex and cerebellum play a prominent role in the development of social communication, whereas fronto-parietal-cerebellar networks are involved in the planning of movements, that is, movement selection. Atypical sensory responsivity, a core feature of ASD, may result in impaired development of social communication and motor skills and/or selection of atypical repetitive behaviour. In the first postnatal year, the brain areas involved are characterized by gradual dissolution of temporary structures: the fronto-temporo-parietal cortical subplate and cerebellar external granular layer. It is hypothesized that altered dissolution of the transient structures opens the window for the expression of early signs of ASD arising in the impaired developing permanent networks. WHAT THIS PAPER ADDS: The early social and motor signs of autism spectrum disorder emerge between the ages of 6 and 12 months. Altered dissolution of transient brain structures in the fronto-temporo-parietal cortex and cerebellum may underlie the emergence of these early signs.

Instructors' Perspectives of Social and Motor Influences on Participation in Children With Autism Spectrum Disorder

Participation is key to childhood development and is essential for health and well-being; yet children with Autism Spectrum Disorder (ASD) participate less in social and physical activities compared to their typically developing peers and little is known about how social and motor challenges impact participation patterns. Purpose: The current research garnered experiential insights of the quality and quantity of participation, through the lens of instructors (N = 9) working with a child or children with ASD. Method: Semi-structured qualitative interviews were conducted to capture a comprehensive and informative profile of how social and motor functioning of children with ASD influence involvement in social and physical activities. Results: Thematic analysis revealed consistent viewpoints in four main areas: (1) Viewpoints extend beyond the World Health Organization definition of participation; (2) Participation depends on who is involved; (3) Although motivation, confidence, and competence in social/motor domains underlie participation, social challenges were perceived as the greatest barrier; (4) While acknowledging the benefits of participation, it is necessary to be cognizant of the required supports. Throughout these themes, the notion of heterogeneity was made very clear. Conclusion: Collectively, perspectives offer descriptive insight which may be useful when designing opportunities for participation in social and physical activities among children with ASD.

A HAND USE AND GRASP SENSOR SYSTEM IN MONITORING INFANT FINE MOTOR DEVELOPMENT

Objective

To assess the feasibility of a hand use and grasp sensor system in collecting and quantifying fine motor development longitudinally in an infant's home environment.

Design

Cohort study. Researchers made home visits monthly to participating families to collect grasp data from infants using a hand use and grasp sensor.

Setting

Data collection were conducted in each participant's home.

Participants

A convenience sample of 14 typical developmental infants were enrolled from 3 months to 9 months of age. Two infants dropped out. A total of 62 testing sessions involving 12 infants were available for analysis (N=12).

Interventions

At each session, the infant was seated in a standardized infant seat. Each instrumented toy was hung on the hand use and grasp sensor structure, presented for 6 minutes in 3 feedback modes: visual, auditory, and vibratory.

Main Outcome Measures

Infant grasp frequency and duration, peak grasping force, average grasping force, force coefficient of variation, and proportion of bimanual grasps.

Results

A total of 2832 recorded grasp events from 12 infants were analyzed. In linear mixed-effects model analysis, when interacting with each toy, infants’ peak grasp force, average grasp force, and accumulated grasp time all increased significantly with age (all P<.001). Bimanual grasps also occupied an increasingly greater percentage of infants’ total grasps as they grew older (bar toy P<.001, candy toy P=.021).

Conclusions

We observed significant changes in hand use and grasp sensor outcome measures with age that are consistent with maturation of grasp skills. We envision the evolution of hand use and grasp sensor technology into an inexpensive and convenient tool to track infant grasp development for early detection of possible developmental delay and/or cerebral palsy as a supplement to clinical evaluations.

Gross motor impairment and its relation to social skills in autism spectrum disorder: A systematic review and two meta-analyses

Gross motor ability is associated with profound differences in how children experience and interact with their social world. A rapidly growing literature on motor development in autism spectrum disorder (ASD) indicates that autistic individuals exhibit impairment in gross motor skills. However, due to substantial heterogeneity across studies, it remains unclear which gross motor skills are impaired in ASD, when and for whom these differences emerge, and whether motor and social impairments are related. The present article addressed these questions by synthesizing research on gross motor skills in ASD in two separate meta-analyses. The first examined gross motor deficits in ASD compared to neurotypical (NT) controls, aggregating data from 114 studies representing 6,423 autistic and 2,941 NT individuals. Results demonstrated a significant overall deficit in gross motor skills in ASD (Hedges' g = -1.04) that was robust to methodological and phenotypic variation and was significant at every level of the tested moderators. However, moderation analyses revealed that this deficit was most pronounced for object control skills (i.e., ball skills), clinical assessment measures, and movements of the upper extremities or the whole body. The second meta-analysis investigated whether gross motor and social skills are related in ASD, synthesizing data from 21 studies representing 654 autistic individuals. Findings revealed a modest but significant overall correlation between gross motor and social skills in ASD (r = 0.27). Collectively, results support the conclusion that motor deficits are tied to the core symptoms of ASD. Further research is needed to test the causality and directionality of this relationship. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Intact predictive motor sequence learning in autism spectrum disorder

Atypical motor learning has been suggested to underpin the development of motoric challenges (e.g., handwriting difficulties) in autism. Bayesian accounts of autistic cognition propose a mechanistic explanation for differences in the learning process in autism. Specifically, that autistic individuals overweight incoming, at the expense of prior, information and are thus less likely to (a) build stable expectations of upcoming events and (b) react to statistically surprising events. Although Bayesian accounts have been suggested to explain differences in learning across a range of domains, to date, such accounts have not been extended to motor learning. 28 autistic and 35 non-autistic controls (IQ > 70) completed a computerised task in which they learned sequences of actions. On occasional "surprising" trials, an expected action had to be replaced with an unexpected action. Sequence learning was indexed as the reaction time difference between blocks which featured a predictable sequence and those that did not. Surprise-related slowing was indexed as the reaction time difference between surprising and unsurprising trials. No differences in sequence-learning or surprise-related slowing were observed between the groups. Bayesian statistics provided anecdotal to moderate evidence to support the conclusion that sequence learning and surprise-related slowing were comparable between the two groups. We conclude that individuals with autism do not show atypicalities in response to surprising events in the context of motor sequence-learning. These data demand careful consideration of the way in which Bayesian accounts of autism can (and cannot) be extended to the domain of motor learning.

Central Auditory and Vestibular Dysfunction Are Key Features of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by repetitive behaviors, poor social skills, and difficulties with communication. Beyond these core signs and symptoms, the majority of subjects with ASD have some degree of auditory and vestibular dysfunction. Dysfunction in these sensory modalities is significant as normal cognitive development depends on an accurate representation of our environment. The hearing difficulties in ASD range from deafness to hypersensitivity and subjects with ASD have abnormal sound-evoked brainstem reflexes and brainstem auditory evoked potentials. Vestibular dysfunction in ASD includes postural instability, gait dysfunction, and impaired gaze. Untreated vestibular dysfunction in children can lead to delayed milestones such as sitting and walking and poor motor coordination later in life. Histopathological studies have revealed that subjects with ASD have significantly fewer neurons in the auditory hindbrain and surviving neurons are smaller and dysmorphic. These findings are consistent with auditory dysfunction. Further, the cerebellum was one of the first brain structures implicated in ASD and studies have revealed loss of Purkinje cells and the presence of ectopic neurons. Together, these studies suggest that normal auditory and vestibular function play major roles in the development of language and social abilities, and dysfunction in these systems may contribute to the core symptoms of ASD. Further, auditory and vestibular dysfunction in children may be overlooked or attributed to other neurodevelopmental disorders. Herein we review the literature on auditory and vestibular dysfunction in ASD. Based on these results we developed a brainstem model of central auditory and vestibular dysfunction in ASD and propose that simple, non-invasive but quantitative testing of hearing and vestibular function be added to newborn screening protocols.

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.

Motor planning and movement execution during goal-directed sequential manual movements in 6-year-old children with autism spectrum disorder: A kinematic analysis

BACKGROUND

Atypical motor functioning is prevalent in children with autism spectrum disorder (ASD). Knowledge of the underlying kinematic properties of these problems is sparse.

AIMS

To investigate characteristics of manual motor planning and performance difficulties/diversity in children with ASD by detailed kinematic measurements. Further, associations between movement parameters and cognitive functions were explored.

METHODS AND PROCEDURES

Six-year-old children with ASD (N = 12) and typically developing (TD) peers (N = 12) performed a sequential manual task comprising grasping and fitting a semi-circular peg into a goal-slot. The goal-slot orientation was manipulated to impose different motor planning constraints. Movements were recorded by an optoelectronic system.

OUTCOMES AND RESULTS

The ASD-group displayed less efficient motor planning than the TD-group, evident in the reach-to-grasp and transport kinematics and less proactive adjustments of the peg to the goal-slot orientations. The intra-individual variation of movement kinematics was higher in the ASD-group compared to the TD-group. Further, in the ASD-group, movement performance associated negatively with cognitive functions.

CONCLUSIONS AND IMPLICATIONS

Planning and execution of sequential manual movements proved challenging for children with ASD, likely contributing to problems in everyday actions. Detailed kinematic investigations contribute to the generation of specific knowledge about the nature of atypical motor performance/diversity in ASD. This is of potential clinical relevance.

A wearable ring-shaped inertial system to identify action planning impairments during reach-to-grasp sequences: a pilot study

Background

The progressive ageing of the population is leading to an increasing number of people affected by cognitive decline, including disorders in executive functions (EFs), such as action planning. Current procedures to evaluate cognitive decline are based on neuropsychological tests, but novel methods and approaches start to be investigated. Reach-to-grasp (RG) protocols have shown that intentions can influence the EFs of action planning. In this work, we proposed a novel ring-shaped wearable inertial device, SensRing, to measure kinematic parameters during RG and after-grasp (AG) tasks with different end-goals. The aim is to evaluate whether SensRing can characterize the motor performances of people affected by Mild Neurocognitive Disorder (MND) with impairment in EFs.

Methods

Eight Individuals with dysexecutive MND, named d-MND, were compared to ten older healthy subjects (HC). They were asked to reach and grasp a can with three different intentions: to drink (DRINK), to place it on a target (PLACE), or to pass it to a partner (PASS). Twenty-one kinematic parameters were extracted from SensRing inertial data.

Results

Seven parameters resulted able to differentiate between HC and d-MND in the RG phase, and 8 features resulted significant in the AG phase. d-MND, indeed, had longer reaction times (in RG PLACE), slower peak velocities (in RG PLACE and PASS, in AG DRINK and PLACE), longer deceleration phases (in all RG and AG DRINK), and higher variability (in RG PLACE, in AG DRINK and PASS). Furthermore, d-MND showed no significant differences among conditions, suggesting that impairments in EFs influence their capabilities in modulating the action planning based on the end-goal.

Conclusions

Based on this explorative study, the system might have the potential for objectifying the clinical assessment of people affected by d-MND by administering an easy motor test. Although these preliminary results have to be investigated in-depth in a larger sample, the portability, wearability, accuracy, and ease-of use of the system make the SensRing potentially appliable for remote applications at home, including analysis of protocols for neuromotor rehabilitation in patients affected by MND.

The Association among Autistic Traits, Interactional Synchrony and Typical Pattern of Motor Planning and Execution in Neurotypical Individuals

Autism spectrum disorder (ASD) is characterized by deficits in interactional synchrony and motor performance, but little is known about the association between them. The current study investigated the association among aberrant interactional synchrony (as measured by interactors’ symmetry in the form of the hand at each time-point along movement’s execution), motor functioning and the level of Autistic traits. In this study, autistic traits were evaluated by the Autistic Spectrum Quotient (AQ). Two tasks were used: (1) an interactional synchrony task where participants and the research assistant were instructed to move their hands together; and (2) a motor planning task which allows for continuous monitoring of natural hand movements. Pearson correlation analysis indicated a significant association between lower communication skills (i.e., higher AQ communication scores) and lower intentional synchrony rates. In addition, lower communication skills were found associated with typical patterns of motor planning and execution characterized by shorter time to start the movement and higher value of max speed. Mediator analyses supported the notion that aberrant intentional synchrony in individuals with low communication skills is partially mediated through typical patterns of motor planning and execution. These results suggest typical patterns of motor functions may account for intentional synchrony difficulties.

Using Technology to Identify Children With Autism Through Motor Abnormalities

Autism is a neurodevelopmental disorder typically assessed and diagnosed through observational analysis of behavior. Assessment exclusively based on behavioral observation sessions requires a lot of time for the diagnosis. In recent years, there is a growing need to make assessment processes more motivating and capable to provide objective measures of the disorder. New evidence showed that motor abnormalities may underpin the disorder and provide a computational marker to enhance assessment and diagnostic processes. Thus, a measure of motor patterns could provide a means to assess young children with autism and a new starting point for rehabilitation treatments. In this study, we propose to use a software tool that through a smart tablet device and touch screen sensor technologies could be able to capture detailed information about children's motor patterns. We compared movement trajectories of autistic children and typically developing children, with the aim to identify autism motor signatures analyzing their coordinates of movements. We used a smart tablet device to record coordinates of dragging movements carried out by 60 children (30 autistic children and 30 typically developing children) during a cognitive task. Machine learning analysis of children's motor patterns identified autism with 93% accuracy, demonstrating that autism can be computationally identified. The analysis of the features that most affect the prediction reveals and describes the differences between the groups, confirming that motor abnormalities are a core feature of autism.

Identifying the signature of prospective motor control in children with autism

Failure to develop prospective motor control has been proposed to be a core phenotypic marker of autism spectrum disorders (ASD). However, whether genuine differences in prospective motor control permit discriminating between ASD and non-ASD profiles over and above individual differences in motor output remains unclear. Here, we combined high precision measures of hand movement kinematics and rigorous machine learning analyses to determine the true power of prospective movement data to differentiate children with autism and typically developing children. Our results show that while movement is unique to each individual, variations in the kinematic patterning of sequential grasping movements genuinely differentiate children with autism from typically developing children. These findings provide quantitative evidence for a prospective motor control impairment in autism and indicate the potential to draw inferences about autism on the basis of movement kinematics.

Brief Report: Reduced Heart Rate Variability in Children with Autism Spectrum Disorder

Dysregulation of the autonomic nervous system (ANS), which can be indexed by heart rate variability (HRV), has been posited to contribute to core features of autism spectrum disorder (ASD). However, the relationship between ASD and HRV remains uncertain. We assessed tonic and phasic HRV of 21 children with ASD and 21 age- and IQ-matched typically developing (TD) children and examined (1) group differences in HRV and (2) associations between HRV and ASD symptomatology. Children with ASD showed significantly lower tonic HRV, but similar phasic HRV compared to TD children. Additionally, reduced tonic HRV was associated with atypical attentional responsivity in ASD. Our findings suggest ANS dysregulation is present in ASD and may contribute to atypical attentional responses to sensory stimulation.

Analysis of the motor performance of children with ASD and its relationship with personal and contextual variables

Background

A high number of individuals with Autism Spectrum Disorder (ASD) present motor deficits. The objectives of this study were (1) to evaluate the motor performance of children with ASD and (2) to analyze the influence that sociodemographic variables and difficulties related to learning have in the development of motor deficits.

Method

Participants were 23 boys and 5 girls with ASD between 4-14 years old. Impairments in motor development were evaluated using the Movement assessment battery for children-2 (MABC-2). Parents provided information on the personal and contextual variables of the participants through a sociodemographic questionnaire and they reported the motor skills of their children through the Checklist of the MABC-2.

Results

The results suggest that most children with ASD present difficulties in balance and in fine and gross motor skills. Likewise, the analysis of the χ2 tests suggested that curricular adaptations, the presence of siblings and traits such as impulsivity, hyperactivity and speech difficulties are factors related to their motor development.

Conclusions

The findings highlight the need to address these difficulties from an early age to stimulate and encourage their development.

SensRing, a novel wearable ring-shaped device for objective analysis of reachto-grasp movements

Reach-to-grasp actions have been recently studied to highlight how intentions influence action planning and shapes the movement kinematics. Reach-to-grasp (RG) kinematics can reveal important information on motor planning and control in several pathologies, including neurodegenerative diseases. Current methods are mainly based on optoelectronic analysis systems, which provide accurate movement tracking but are expensive, time-consuming, and limited to constrained research-oriented space. In this study, we proposed an innovative, non-invasive, and easy-to-use ringshaped wearable system, named SensRing, able to record inertial data during the movement. To ensure accurate and precise measures, which are mandatory for clinical practice, a preliminary technical validation of the SensRing with respect to the Vicon (i.e., gold standard for motion analysis) was performed on two finger tapping exercises. Preliminary results pointed out very low discrepancies in terms of absolute errors (AbsErr) between the values of repetitions (AbsErr≤0.8), frequency (AbsErr=0.04Hz) and amplitude (AbsErr≤2.7deg) measured by the two systems, as well as high correlation between the measures obtained with the inertial and optical system. Therefore, inertial data from the SensRing were used in a "reach-to-grasp and move" protocol to calculate the performance of a group of healthy young subjects during three RG and move sequences. Particularly, subjects were instructed to reach and grasp a bottle to drink (DRINK), to place it on the table (IND) or to pass it to another partner (SOC). Results showed that SensRing could identify that, in the RG phase, different intentions determine different kinematic parameters of grasping the same object. As concerns the phase of moving, if the movement is different (drink vs IND/SOC) it's easier to find differences between the tasks, but also when the action is the same but with different social intent (IND vs SOC) SensRing found a significant difference.

Motor atypicalities in infancy are associated with general developmental level at 2 years, but not autistic symptoms

LAY ABSTRACT

Atypicalities in motor functioning are often observed in later born infant siblings of children with autism spectrum disorder. The goal of our study was to investigate motor functioning in infants with and without familial history of autism spectrum disorder. Specifically, we investigated how infants catch a ball that is rolling toward them following a non-straight path, a task that requires both efficient planning and execution. Their performance was measured using detailed three-dimensional motion capture technology. We found that several early motor functioning measures were different in infants with an older autistic sibling compared to controls. However, these early motor measures were not related to autistic symptoms at the age of 2 years. Instead, we found that some of the early motor measures were related to their subsequent non-social, general development. The findings of our study help us understand motor functioning early in life and how motor functioning is related to other aspects of development.

Postural control processes during standing and step initiation in autism spectrum disorder

Background

Individuals with autism spectrum disorder (ASD) show a reduced ability to maintain postural stability, though motor control mechanisms contributing to these issues and the extent to which they are associated with other gross motor activities (e.g., stepping) are not yet known.

Methods

Seventeen individuals with ASD and 20 typically developing (TD) controls (ages 6–19 years) completed three tests of postural control during standing. During the neutral stance, individuals stood with their feet shoulder width apart. During the Romberg one stance, they stood with feet close together. During the circular sway, participants stood with feet shoulder width apart and swayed in a circular motion. The standard deviation (SD) of their center of pressure (COP) in the mediolateral (ML) and anteroposterior (AP) directions and the COP trajectory length were examined for each stance. We also assessed mutual information (MI), or the shared dependencies between COP in the ML and AP directions. Participants also completed a stepping task in which they stepped forward from one force platform to an adjacent platform. The amplitude and duration of anticipatory postural adjustments (APAs) were examined, as were the maximum lateral sway, duration, and velocity of COP adjustments following the initial step. We examined stepping variables using separate one-way ANCOVAs with height as a covariate. The relationships between postural control and stepping measures and ASD symptom severity were assessed using Spearman correlations with scores on the Autism Diagnostic Observation Schedule–Second Edition (ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R).

Results

Individuals with ASD showed increased COP trajectory length across stance conditions (p = 0.05) and reduced MI during circular sway relative to TD controls (p = 0.02). During stepping, groups did not differ on APA amplitude (p = 0.97) or duration (p = 0.41), but during their initial step, individuals with ASD showed reduced ML sway (p = 0.06), reduced body transfer duration (p < 0.01), and increased body transfer velocity (p = 0.02) compared to controls. Greater neutral stance COP_ML variability (r = 0.55, p = 0.02) and decreased lateral sway (r = − 0.55, p = 0.02) when stepping were associated with more severe restricted and repetitive behaviors in participants with ASD.

Conclusions

We found that individuals with ASD showed reduced MI during circular sway suggesting a reduced ability to effectively coordinate joint movements during dynamic postural adjustments. Additionally, individuals with ASD showed reduced lateral sway when stepping indicating that motor rigidity may interfere with balance and gait. Postural control and stepping deficits were related to repetitive behaviors in individuals with ASD indicating that motor rigidity and key clinical issues in ASD may represent overlapping pathological processes.

Combined Transcranial Direct Current Stimulation and Selective Motor Training Enhances Balance in Children With Autism Spectrum Disorder

Previous studies have shown that transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) can facilitate the consolidation of motor skills in people who are typically developed, especially when tDCS is combined with goal-oriented exercises. Yet, the effect of tDCS on the motor skills of children with autism spectrum disorder is unknown. This study sought to investigate the effects of combined anodal tDCS and selective motor training on balance among 18 children with autism spectrum disorder (aged 6–14 years) who we randomly assigned to equal-sized experimental and control groups. The experimental group practiced motor training to improve balance after receiving 1.5 mA anodal tDCS over the left M1 for 20 minutes before each of 10 motor training sessions. The control (sham) group underwent a similar protocol with identical motor training, but tDCS was only artificially administered to them. We evaluated participants’ balance at baseline and after training. Data analysis showed that both anodal tDCS plus motor skill training and motor skill training with sham tDCS had significant positive impacts on balance, but tDCS participants who received both actual tDCS and motor skill training performed significantly better than those who received SHAM tDCS and motor skill training. These preliminary findings suggest that tDCS may enhance motor skill training for children with autism spectrum disorder, but replications with larger samples involving participants with varying levels of autistic symptoms and varied tDCS stimulation polarity are needed to affirm the practical use of this noninvasive brain stimulation.

Four Social Brain Regions, Their Dysfunctions, and Sequelae, Extensively Explain Autism Spectrum Disorder Symptomatology

Autism spectrum disorder (ASD) is a challenging neurodevelopmental disorder with symptoms in social, language, sensory, motor, cognitive, emotional, repetitive behavior, and self-sufficient living domains. The important research question examined is the elucidation of the pathogenic neurocircuitry that underlies ASD symptomatology in all its richness and heterogeneity. The presented model builds on earlier social brain research, and hypothesizes that four social brain regions largely drive ASD symptomatology: amygdala, orbitofrontal cortex (OFC), temporoparietal cortex (TPC), and insula. The amygdala's contributions to ASD largely derive from its major involvement in fine-grained intangible knowledge representations and high-level guidance of gaze. In addition, disrupted brain regions can drive disturbance of strongly interconnected brain regions to produce further symptoms. These and related effects are proposed to underlie abnormalities of the visual cortex, inferior frontal gyrus (IFG), caudate nucleus, and hippocampus as well as associated symptoms. The model is supported by neuroimaging, neuropsychological, neuroanatomical, cellular, physiological, and behavioral evidence. Collectively, the model proposes a novel, parsimonious, and empirically testable account of the pathogenic neurocircuitry of ASD, an extensive account of its symptomatology, a novel physiological biomarker with potential for earlier diagnosis, and novel experiments to further elucidate the mechanisms of brain abnormalities and symptomatology in ASD.

Toward a motor signature in autism: Studies from human-machine interaction

BACKGROUND

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders which core symptoms are impairments in socio-communication and repetitive symptoms and stereotypies. Although not cardinal symptoms per se, motor impairments are fundamental aspects of ASD. These impairments are associated with postural and motor control disabilities that we investigated using computational modeling and developmental robotics through human-machine interaction paradigms.

METHOD

First, in a set of studies involving a human-robot posture imitation, we explored the impact of 3 different groups of partners (including a group of children with ASD) on robot learning by imitation. Second, using an ecological task, i.e. a real-time motor imitation with a tightrope walker (TW) avatar, we investigated interpersonal synchronization, motor coordination and motor control during the task in children with ASD (n=29), TD children (n=39) and children with developmental coordination disorder (n=17, DCD).

RESULTS

From the human-robot experiments, we evidenced that motor signature at both groups' and individuals' levels had a key influence on imitation learning, posture recognition and identity recognition. From the more dynamic motor imitation paradigm with a TW avatar, we found that interpersonal synchronization, motor coordination and motor control were more impaired in children with ASD compared to both TD children and children with DCD. Taken together these results confirm the motor peculiarities of children with ASD despite imitation tasks were adequately performed.

DISCUSSION

Studies from human-machine interaction support the idea of a behavioral signature in children with ASD. However, several issues need to be addressed. Is this behavioral signature motoric in essence? Is it possible to ascertain that these peculiarities occur during all motor tasks (e.g. posture, voluntary movement)? Could this motor signature be considered as specific to autism, notably in comparison to DCD that also display poor motor coordination skills? We suggest that more work comparing the two conditions should be implemented, including analysis of kinematics and movement smoothness with sufficient measurement quality to allow spectral analysis.

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.

What's missing in autism spectrum disorder motor assessments?

BACKGROUND

Motor delays and impairments in autism spectrum disorders (ASD) are extremely common and often herald the emergence of pervasive atypical development. Clinical accounts of ASD and standardized measures of motor function have identified deficits in multiple motor domains. However, literature describing frequently used standardized motor assessments in children with ASD, their test properties, and their limitations are sparse.

METHODS

We systematically reviewed the literature to identify the most frequently used standardized motor assessments used to evaluate children with ASD from infancy to early childhood. All assessments included were required to possess reference norms, evaluate more than one motor domain, and have undergone some degree of validation.

RESULTS

We identified six frequently used standardized measures of motor function per our inclusion and exclusion criteria. We investigated and described in detail the psychometric properties of these assessments, their utility for use with children with ASD, and their individual and overall strengths and limitations. The global strengths of these assessments are the ability to identify early development delays and differences in fine and gross motor function in children with ASD. Global limitations of these studies are lack of validation in individuals with ASD and scoring systems that often miss specific and subtle abnormalities.

CONCLUSIONS

Standardized assessments of motor function have provided valuable information on motor impairments in ASD. However, significant limitations remain in the use of these measures in children with ASD. Moving forward, it is imperative that standardized measures of motor function receive greater validation testing in children with ASD to assess their potential application given the clinical heterogeneity of this condition. In addition, utilizing quantitative measures of motor function should allow for evaluation and comparison of individuals with ASD across the lifespan with varying cognitive and behavioral abilities.

Differences in means-end exploration between infants at risk for autism and typically developing infants in the first 15 months of life

Our study compared means-end exploration in infants at risk (AR) for autism and typically developing (TD) infants using a nested box paradigm. Sixteen AR and 16 TD infants were observed at 9, 12, and 15 months with follow-up at 18 and 24 months. We collected video data on three tasks involving retrieval of a small toy by opening (a) an opaque box, (b) a transparent box, and (c) two nested boxes. Dependent variables included hand bias, time to completion, bilateral hand use, problem-solving strategies used, and tester assistance required. There were no group differences in terms of hand biases. Compared to TD infants, AR infants had lower bilateral hand use, poor problem solving skills, and required greater assistance. Both groups demonstrated age-related improvements in motor and cognitive skills. Means-end exploration provides a window into the bilateral coordination and motor planning/problem-solving abilities of young infants at risk for autism. Lastly, object retrieval tasks could serve as important learning contexts for at-risk infants.

Older Adolescents and Young Adults With Autism Spectrum Disorder Have Difficulty Chaining Motor Acts When Performing Prehension Movements Compared to Typically Developing Peers

It is known that motor actions performed by individuals with autism spectrum disorders (ASD) are clumsy and a previous study revealed that children with ASD of around 8 years old showed less smooth movement and dysfunction of appropriate usage of online vision for grip aperture control. The present study investigates whether and how the kinematic properties of reach-to-grasp movements in older adolescents and adults with ASD [mean (±SD) age: 18.3 ± 2.1] differ from those in typically developing (TD) peers [mean (±SD) age: 19.1 ± 2.2]. Revealing the kinematic properties of reach-to-grasp movements in older adolescents and adults with ASD is indispensable in determining the developmental trajectory of this motor behavior in individuals with ASD. While wearing liquid crystal shutter goggles, participants reached for and grasped a cylinder with a diameter of either 4 or 6 cm. Two visual conditions were tested: a full vision (FV) condition (the goggles remained transparent during the movement) and a no vision (NV) condition (the goggles were closed immediately after the movement was initiated). These two visual conditions were either alternated with each trial in a single experimental session (alternated condition) or blocked within the session (blocked condition). We found that the reaching movement smoothness calculated as a normalized jerk score (i.e., index of skilled, coordinated human movements) of ASD participants did not differ significantly from that of TD peers although ASD participants showed smoother reaching in the alternated condition than in the blocked condition. The influence of online vision and its visual condition schedule on grip aperture during the in-flight phase was remarkably similar between the ASD and TD groups. Furthermore, we found that ASD group experienced a significant longer transition period from grasping end (i.e., stable holding when touching the surface of the object) to uplift initiation than the TD group. The results suggest that (1) deficits in movement smoothness and the use of online vision for motor control are rectified by the time individuals with ASD reach late adolescence and (2) older adolescents and adults with ASD still have difficulties chaining motor acts.

Interpersonal motor coordination during joint actions in children with and without autism spectrum disorder: The role of motor information

BACKGROUND

Kinematics plays a key role in action prediction, imitation and joint action coordination. Despite people with autism spectrum disorder (ASD) show a failure to use kinematic cues during observation and imitation, there is a paucity of studies exploring the role of this dysfunction during joint actions in children with ASD.

AIM

To evaluate the interpersonal motor coordination of children with ASD and typically developing (TD) children during a joint action task.

METHOD

Twenty-two participants performed two cooperative tasks. In the first one (Clear End-Point), children were provided with a priori information on movement end-point. In the second one (Unclear End-Point), the end-point was unknown and children had to use kinematic cues to accomplish the shared goal.

RESULTS

We found no between-group differences in the first task, even if children with ASD displayed greater reaction time variability. In the second task, they showed less accurate and slower movements than TD children. Moreover, their movement features did not differ between the two tasks, whereas TD children showed reduced reaction time variability and number of errors in the second task.

CONCLUSION

Children with ASD were impaired in joint action coordination when they had to rely only on kinematic information. They were not able to pay more attention to the kinematic cues in absence of a visual goal.

Are Motor Control and Regulation Problems Part of the ASD Motor Profile? A Handwriting Study

The primary aim of this study was to kinematically assess how children with autism spectrum disorder (ASD) plan and control their handwriting actions. Forty-three boys aged between 8 to 12 years were included in the present analysis; 23 with ASD and 20 typically developing (TD) controls. Sophisticated objective and quantifiable assessment of movement metrics and dynamics was applied across a series of basic cursive handwriting sequences. Children with ASD demonstrated atypical control of handwriting metrics and dynamics, as well as significantly greater neuromotor noise relative to age-matched peers. They also engaged in less regular monitoring and regulation of their movement during the handwriting task. This study provides new insights into the way children with ASD plan and sequence their handwriting movements. Overall, results revealed that even at a basic level, children with ASD appear to have a breakdown in their ability to control and regulate their handwriting movements. This has important implications for the school-aged child who constantly engages in handwriting tasks within the classroom environment and provides insight into possible directions for future intervention.

Autism-related behaviors in the cyclooxygenase-2-deficient mouse model

Prostaglandin E2 (PGE2) is an endogenous lipid molecule involved in normal brain development. Cyclooxygenase-2 (COX2) is the main regulator of PGE2 synthesis. Emerging clinical and molecular research provides compelling evidence that abnormal COX2/PGE2 signaling is associated with autism spectrum disorder (ASD). We previously found that COX2 knockout mice had dysregulated expression of many ASD genes belonging to important biological pathways for neurodevelopment. The present study is the first to show the connection between irregular COX2/PGE2 signaling and autism-related behaviors in male and female COX2-deficient knockin, (COX)-2^- , mice at young (4-6 weeks) or adult (8-11 weeks) ages. Autism-related behaviors were prominent in male (COX)-2^- mice for most behavioral tests. In the open field test, (COX)-2^- mice traveled more than controls and adult male (COX)-2^- mice spent less time in the center indicating elevated hyperactive and anxiety-linked behaviors. (COX)-2^- mice also buried more marbles, with males burying more than females, suggesting increased anxiety and repetitive behaviors. Young male (COX)-2^- mice fell more frequently in the inverted screen test revealing motor deficits. The three-chamber sociability test found that adult female (COX)-2^- mice spent less time in the novel mouse chamber indicative of social abnormalities. In addition, male (COX)-2^- mice showed altered expression of several autism-linked genes: Wnt2, Glo1, Grm5 and Mmp9. Overall, our findings offer new insight into the involvement of disrupted COX2/PGE2 signaling in ASD pathology with age-related differences and greater impact on males. We propose that (COX)-2^- mice might serve as a novel model system to study specific types of autism.

Is there a generalized timing impairment in Autism Spectrum Disorders across time scales and paradigms?

Individuals with ASD have abnormal motor and perceptual functions that do not currently form diagnostic criteria of ASD, but nevertheless may affect everyday behaviour. Temporal processing seems to be one of such non-diagnostic yet impaired domains, although the lack of systematic studies testing different aspects of timing in the same sample of participants prevents a conclusive assessment of whether there is a generalized temporal deficit in ASD associated with diagnostic symptoms. 17 children diagnosed with ASD and 18 typically developing age- and IQ-matched controls carried out a set of motor and perceptual timing tasks: free tapping, simultaneity judgment, auditory duration discrimination, and verbal duration estimation. Parents of participants filled in a questionnaire assessing the sense and management of time. Children with ASD showed faster and more variable free tapping than controls. Auditory duration discrimination thresholds were higher in the ASD group than controls in a sub-second version of the task, while there were no group differences in a supra-second discrimination of intervals. Children with ASD showed more variable thresholds of simultaneity judgment, and they received lower parental scores for their sense and management of time. No group differences were observed in the verbal duration estimation task in the minute-range. Different timing functions were correlated in the ASD group but not among controls, whilst several timing measures correlated with ASD symptoms. We conclude that children with ASD show a broad range of abnormalities in temporal processing tasks including motor timing, perceptual timing, and temporal perspective.

Abnormal Speech Motor Control in Individuals with 16p11.2 Deletions

Speech and motor deficits are highly prevalent (>70%) in individuals with the 600 kb BP4-BP5 16p11.2 deletion; however, the mechanisms that drive these deficits are unclear, limiting our ability to target interventions and advance treatment. This study examined fundamental aspects of speech motor control in participants with the 16p11.2 deletion. To assess capacity for control of voice, we examined how accurately and quickly subjects changed the pitch of their voice within a trial to correct for a transient perturbation of the pitch of their auditory feedback. When compared to controls, 16p11.2 deletion carriers show an over-exaggerated pitch compensation response to unpredictable mid-vocalization pitch perturbations. We also examined sensorimotor adaptation of speech by assessing how subjects learned to adapt their sustained productions of formants (speech spectral peak frequencies important for vowel identity), in response to consistent changes in their auditory feedback during vowel production. Deletion carriers show reduced sensorimotor adaptation to sustained vowel identity changes in auditory feedback. These results together suggest that 16p11.2 deletion carriers have fundamental impairments in the basic mechanisms of speech motor control and these impairments may partially explain the deficits in speech and language in these individuals.

Motor Skills as Moderators of Core Symptoms in Autism Spectrum Disorders: Preliminary Data From an Exploratory Analysis With Artificial Neural Networks

Motor disturbances have been widely observed in children with autism spectrum disorder (ASD), and motor problems are currently reported as associated features supporting the diagnosis of ASD in the current Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Studies on this issue reported disturbances in different motor domains, including both gross and fine motor areas as well as coordination, postural control, and standing balance. However, they failed to clearly state whether motor impairments are related to demographical and developmental features of ASD. Both the different methodological approaches assessing motor skills and the heterogeneity in clinical features of participants analyzed have been implicated as contributors to variance in findings. However, the non-linearity of the relationships between variables may account for the inability of the traditional analysis to grasp the core problem suggesting that the "single symptom approach analysis" should be overcome. Artificial neural networks (ANNs) are computational adaptive systems inspired by the functioning processes of the human brain particularly adapted to solving non-linear problems. This study aimed to apply the ANNs to reveal the entire spectrum of the relationship between motor skills and clinical variables. Thirty-two male children with ASD [mean age: 48.5 months (SD: 8.8); age range: 30-60 months] were recruited in a tertiary care university hospital. A multidisciplinary comprehensive diagnostic evaluation was associated with a standardized assessment battery for motor skills, the Peabody Developmental Motor Scale-Second Edition. Exploratory analyses were performed through the ANNs. The findings revealed that poor motor skills were a common clinical feature of preschoolers with ASD, relating both to the high level of repetitive behaviors and to the low level of expressive language. Moreover, unobvious trends among motor, cognitive and social skills have been detected. In conclusion, motor abnormalities in preschoolers with ASD were widespread, and the degree of impairment may inform clinicians about the severity of ASD core symptoms. Understanding motor disturbances in children with ASD may be relevant to clarify neurobiological basis and ultimately to guide the development of tailored treatments.