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.

Community-based postural control assessment in autistic individuals indicates a similar but delayed trajectory compared to neurotypical individuals.

Autistic individuals exhibit significant sensorimotor differences. Postural stability and control are foundational motor skills for successfully performing many activities of daily living. In neurotypical development, postural stability and control develop throughout childhood and adolescence. In autistic development, previous studies have focused primarily on individual age groups (e.g., childhood, adolescence, adulthood) or only controlled for age using age-matching. Here, we examined the age trajectories of postural stability and control in autism from childhood through adolescents using standardized clinical assessments. In study 1, we tested the postural stability of autistic (n = 27) and neurotypical (n = 41) children, adolescents, and young adults aged 7-20 years during quiet standing on a force plate in three visual conditions: eyes open (EO), eyes closed (EC), and eyes open with the head in a translucent dome (Dome). Postural sway variability decreased as age increased for both groups, but autistic participants showed greater variability than neurotypical participants across age. In study 2, we tested autistic (n = 21) and neurotypical (n = 32) children and adolescents aged 7-16 years during a dynamic postural control task with nine targets. Postural control efficiency increased as age increased for both groups, but autistic participants were less efficient compared to neurotypical participants across age. Together, these results indicate that autistic individuals have a similar age trajectory for postural stability and control compared to neurotypical individuals, but have lower postural stability and control overall.

Autistic Children Use Less Efficient Goal-Directed Whole Body Movements Compared to Neurotypical Development.

Autistic children have differences in their movements which impact their functional performance. Virtual-reality enables researchers to study movement in safe, engaging environments. We used motion-capture to measure how 7-13-year-old autistic and neurotypical children make whole-body movements in a virtual-reality task. Although children in both groups were successful, we observed differences in their movements. Autistic children were less efficient moving to the target. Autistic children did not appear to use a movement strategy. While neurotypical children were more likely to overshoot near targets and undershoot far targets, autistic children did not modulate their strategy. Using kinematic data from tasks in virtual-reality, we can begin to understand the pattern of movement challenges experienced by autistic children.

Movement smoothness during dynamic postural control to a static target differs between autistic and neurotypical children.

BACKGROUND: Autistic children and adults have known differences in motor performance, including postural instability and atypical gross motor control. Few studies have specifically tested dynamic postural control. This is the first study to quantify movement smoothness and its relationship to task performance during lateral dynamic postural control tasks in autism. RESEARCH QUESTION: We sought to test the hypothesis that autistic children would have less smooth movements to lateral static targets compared to neurotypical children, and that this difference would relate to specific movement strategies. METHODS: We used camera-based motion-capture to measure spatiotemporal characteristics of lateral movement of a marker placed on the C7 vertebrae, and of markers comprising trunk and pelvis segments during a dynamic postural movements to near and far targets administered in an immersive virtual environment. We tested a sample of 15 autistic children and 11 age-matched neurotypical children. We quantified movement smoothness using log dimensionless jerk. RESULTS: Autistic children exhibited more medial-lateral pelvic position range of motion compared to neurotypical children, and used a stepping strategy more often compared to neurotypical children. Autistic children also had higher log dimensionless jerk than neurotypical children for motion of the C7 marker. All participants had higher log dimensionless jerk for far targets than for near targets. Autistic children had longer trial durations than neurotypical children, and younger children had longer trial durations than older children across diagnostic groups. SIGNIFICANCE: The stepping strategy observed more often in the autistic group likely contributed to log dimensionless jerk and reduced movement smoothness. This strategy is indicative of either an attempt to prevent an impending loss of balance, or an attempt to compensate for and recover from a loss of balance once it is detected.

Executive Function Brain Network Activation Predicts Driving Hazard Detection in ADHD.

Drivers with neurodevelopmental disorders (NDDs), such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are at increased risk of experiencing driving difficulties. An important aspect of driving safety and skill involves hazard detection. This functional magnetic resonance imaging study examined the neural responses associated with driving hazard detection in drivers with ASD, ADHD, and typically developing (TD) drivers. Forty participants (12 ASD, 15 ADHD, 13 TD) ages 16-30 years completed a driving simulator task in which they encountered social and nonsocial hazards; reaction time (RT) for responding to hazards was measured. Participants then completed a similar hazard detection task in the MRI scanner so that neural response to hazards could be measured. Activation of regions of interest considered part of the executive function (EF) and theory of mind (ToM) networks were examined and related to driving simulator behavior. Results showed that stronger activation of the EF network during social hazard processing, including the bilateral dorsolateral prefrontal cortex and posterior parietal cortex, was associated with faster RT to social hazards among drivers with ADHD, but not among drivers with ASD. This provides the first evidence of a relationship between EF network brain activation and driving skills in ADHD and suggests that alterations in this network may underlie driving behavior. In comparison, the current study did not observe a relationship between ToM network activation and RT to social hazards in any group. This study lays the groundwork for relating neural activation to driving behavior among individuals with NDDs.

Neuropsychological predictors of driving hazard detection in autism spectrum disorder and ADHD.

Driving is a neuropsychologically complex task; this can present challenges for individuals with neurodevelopmental disorders (NDDs) such asautism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Deficits in theory of mind (ToM) and executive function (EF) are common features of ASD and ADHD, respectively, and may influence driving processes such as hazard perception. No studies have directly examined the neuropsychological contributions to hazard detection among drivers with ASD compared to ADHD.In the current study, 48 participants ages 16-30 years (13 ASD, 17 ADHD, 18 typically developing (TD)) completed a driving simulator task in which they encountered hazards in the driving environment. Hazards varied in whether they were social (contained a human component) or nonsocial (were physical objects) to examine the contribution of ToM and social processing to hazard response. Additionally, participants completed a neuropsychological battery targeting ToM and EF/attention skills (cognitive tasks and self-report measures).Within the ASD group, participants responded relatively slower to social compared to nonsocial hazards; no effect of hazard type was observed in the ADHD or TD groups. Additionally, measures of ToM and EF were correlated with driving performanceamong ASD participants; within the ADHD group, only self-reported behavior regulation was associated with driving performance. Broadly, this suggests that cognitive factors such as ToM and EF impact driving hazard performance in ASD and ADHD. The results of the study have implications for developing driving intervention programs for individuals with NDDs.

Shared Features or Co-occurrence? Evaluating Symptoms of Developmental Coordination Disorder in Children and Adolescents with Autism Spectrum Disorder.

Motor differences are common in Autism Spectrum Disorder (ASD), but rarely evaluated against diagnostic criteria for Developmental Coordination Disorder (DCD). We aimed to determine whether motor problems in ASD represent the possible co-occurrence of DCD. We retrospectively reviewed standardized assessments and parent-reports to evaluate motor ability in 43 individuals with ASD against diagnostic criteria for DCD, and compared to 18 individuals with DCD. Over 97% of cases in the ASD group scored below the 16th percentile in motor ability, with most below the 5th percentile. Over 90% of cases in the ASD group met criteria for co-occurring DCD. Motor challenges are a clinically-significant problem in ASD; systematically assessing the prevalence of co-occurring ASD + DCD is necessary to optimize assessment and intervention.

Preliminary Improvements in Dynamic Postural Control after A Group-based Intervention Program for Children with Developmental Coordination Disorder: A Brief Report.

OBJECTIVE: To determine the value of a traditional (easy to implement) group-based intervention program on both static and dynamic postural control in children with Developmental Coordination Disorder (DCD). METHODS: Sway and stability indices were measured with the Clinical Test of Sensory Integration in Balance (CTSIB) and efficiency of goal-directed movement was measured during a Limits-of-Stability (LoS) task, before and after the intervention program. The intervention involved a total of 10 one-hour group sessions, administered once per week for 10 weeks. RESULTS: Results indicated significant group increases in dynamic postural control (p <.05). These results suggest it is possible to improve dynamic postural control in this population. This type of intervention does not require any expensive materials, it is feasible, and easy-to-implement to a group of children. CONCLUSION: We conclude that this simple form of intervention involving fun group activities can significantly improve dynamic postural control in children with DCD.

Children with Autism Spectrum Disorder, Developmental Coordination Disorder, and typical development differ in characteristics of dynamic postural control: A preliminary study.

BACKGROUND: Autism Spectrum Disorder (ASD) and Developmental Coordination Disorder (DCD) are developmental disorders with distinct definitions and symptoms. However, both conditions share difficulties with motor skills, including impairments in postural control. While studies have explored postural sway variables in children with DCD and ASD as compared to typical development (TD), few have used kinematic data to assess the magnitude of differences between these two neurodevelopmental conditions. There are few sensitive and specific measures available to assess balance impairment severity in these populations. RESEARCH QUESTION: Do individuals with ASD, DCD, and TD differ in dynamic postural control? METHODS: We quantified postural control differences between ASD, DCD, and TD during a dynamic balance task. 10 ASD, 10 DCD, and 8 TD agematched children completed a dynamic postural control task in a virtual environment. They leaned to shift their center of pressure (CoP) to match a user-controlled object to an oscillating target (0.1 Hz-0.8 Hz). RESULTS: The DCD group had higher CoP accelerations compared to ASD or TD. While the DCD and TD groups did not differ in their medial-lateral velocity, the ASD group had low medial-lateral velocity and acceleration as compared to DCD and TD. ASD group velocity and acceleration did not differ from that of the TD group in the anterior-posterior direction. Higher accelerations in the DCD group reflected non-fluid movements; by contrast, the ASD group had slower, more fluid movements. Results may reflect differences in how children with ASD and DCD plan, execute, and modify motor actions. SIGNIFICANCE: This study demonstrates the potential utility of CoP acceleration and velocity as a sensitive and specific means of differentiating between ASD, DCD, and TD. Results indicating group differences between ASD and DCD in velocity and acceleration profiles represent an important step toward understanding how these populations modify motor plans during dynamic tasks.