Brief report: planning problems in autism at the level of motor control

Effects of developmental hyperserotonemia on the morphology of rat dentate nuclear neurons

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social cognition, disordered communication, restricted interests and repetitive behaviors. Furthermore, abnormalities in basic motor control, skilled motor gestures, and motor learning, are common in ASD. These characteristics have been attributed to a possible defect in the pre- and postnatal development of specific neural networks including the dentate-thalamo-cortical pathway, which is involved in motor learning, automaticity of movements, and higher cognitive functions. The current study utilized custom diolistic labeling and unbiased stereology to characterize morphological alterations in neurons of the dentate nucleus of the cerebellum in developing rat pups exposed to abnormally high levels of the serotonergic agonist 5-methyloxytryptamine (5-MT) pre-and postnatally. Occurring in as many as 30% of autistic subjects, developmental hyperserotonemia (DHS) is the most consistent neurochemical finding reported in autism and has been implicated in the pathophysiology of ASD. This exposure produced dramatic changes in dendritic architecture and synaptic features. We observed changes in the dendritic branching morphology which did not lead to significant differences (p>0.5) in total dendritic length. Instead, DHS groups presented with dendritic trees that display changes in arborescence, that appear to be short reaching with elaborately branched segments, presenting with significantly fewer (p>0.001) dendritic spines and a decrease in numeric density when compared to age-matched controls. These negative changes may be implicated in the neuropathological and functional/behavioral changes observed in ASD, such as delays in motor learning, difficulties in automaticity of movements, and deficits in higher cognitive functions.

Sensorimotor dysfunctions as primary features of autism spectrum disorders

Motor impairments in autism spectrum disorders (ASD) have received far less research attention than core social-communication and cognitive features. Yet, behavioral, neurophysiological, neuroimaging and histopathological studies have documented abnormal motor system development in the majority of individuals with ASD suggesting that these deficits may be primary to the disorder. There are several unique advantages to studying motor development in ASD. First, the neurophysiological substrates of motor skills have been well-characterized via animal and human lesion studies. Second, many of the single- gene disorders associated with ASD also are characterized by motor dysfunctions. Third, recent evidence suggests that the onset of motor dysfunctions may precede the emergence of social and communication deficits during the first year of life in ASD. Motor deficits documented in ASD indicate disruptions throughout the neuroaxis affecting cortex, striatum, the cerebellum and brainstem. Questions remain regarding the timing and development of motor system alterations in ASD, their association with defining clinical features, and their potential for parsing heterogeneity in ASD. Pursuing these questions through neurobiologically informed translational research holds great promise for identifying gene-brain pathways associated with ASD.

Brief Report: Imaginative Drawing in Children with Autism Spectrum Disorder and Learning Disabilities

Here we examine imaginative drawing abilities in children with Autism Spectrum Disorder (ASD) and learning disabilities (LD) under several conditions: spontaneous production, with use of a template, and combining two real entities to form an 'unreal' entity. Sixteen children in each group, matched on mental and chronological age, were asked to draw a number of 'impossible' pictures of humans and dogs. Children with ASD were impaired in spontaneous drawings and included fewer impossible features than children with LD, but there was no difference when a template was provided. An autism-specific deficit was revealed in the task involving combining entities. Results suggest that children with ASD do not have a general imaginative deficit; impairment is instead related to planning demands.

Comparing Motor Skills in Autism Spectrum Individuals With and Without Speech Delay

Movement atypicalities in speed, coordination, posture, and gait have been observed across the autism spectrum (AS) and atypicalities in coordination are more commonly observed in AS individuals without delayed speech (DSM‐IV Asperger) than in those with atypical or delayed speech onset. However, few studies have provided quantitative data to support these mostly clinical observations. Here, we compared perceptual and motor performance between 30 typically developing and AS individuals (21 with speech delay and 18 without speech delay) to examine the associations between limb movement control and atypical speech development. Groups were matched for age, intelligence, and sex. The experimental design included: an inspection time task, which measures visual processing speed; the Purdue Pegboard, which measures finger dexterity, bimanual performance, and hand‐eye coordination; the Annett Peg Moving Task, which measures unimanual goal‐directed arm movement; and a simple reaction time task. We used analysis of covariance to investigate group differences in task performance and linear regression models to explore potential associations between intelligence, language skills, simple reaction time, and visually guided movement performance. AS participants without speech delay performed slower than typical participants in the Purdue Pegboard subtests. AS participants without speech delay showed poorer bimanual coordination than those with speech delay. Visual processing speed was slightly faster in both AS groups than in the typical group. Altogether, these results suggest that AS individuals with and without speech delay differ in visually guided and visually triggered behavior and show that early language skills are associated with slower movement in simple and complex motor tasks. Autism Res2015, 8: 682–693. © 2015 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research

Untrivial Pursuit: Measuring Motor Procedures Learning in Children with Autism

Numerous studies have underscored prevalence of motor impairments in children with autism spectrum disorders (ASD), but only few of them have analyzed motor strategies exploited by ASD children when learning a new motor procedure. To evaluate motor procedure learning and performance strategies in both ASD and typically developing (TD) children, we built a virtual pursuit rotor (VPR) task, requiring tracking a moving target on a computer screen using a digitalized pen and tablet. Procedural learning was measured as increased time on target (TT) across blocks of trials on the same day and consolidation was assessed after a 24-hour rest. The program and the experimental setting (evaluated in a first experiment considering two groups of TD children) allowed also measures of continuous time on target (CTT), distance from target (DT) and distance from path (DP), as well as 2D reconstructions of children's trajectories. Results showed that the VPR was harder for children with ASD than for TD controls matched for chronological age and intelligence quotient, but both groups displayed comparable motor procedure learning (i.e., similarly incremented their TT). However, closer analysis of CTT, DT, and DP as well as 2D trajectories, showed different motor performance strategies in ASD, highlighting difficulties in overall actions planning. Data underscore the need for deeper investigations of motor strategies exploited by children with ASD when learning a new motor procedure.

Autism as a disorder of prediction

A rich collection of empirical findings accumulated over the past three decades attests to the diversity of traits that constitute the autism phenotypes. It is unclear whether subsets of these traits share any underlying causality. This lack of a cohesive conceptualization of the disorder has complicated the search for broadly effective therapies, diagnostic markers, and neural/genetic correlates. In this paper, we describe how theoretical considerations and a review of empirical data lead to the hypothesis that some salient aspects of the autism phenotype may be manifestations of an underlying impairment in predictive abilities. With compromised prediction skills, an individual with autism inhabits a seemingly "magical" world wherein events occur unexpectedly and without cause. Immersion in such a capricious environment can prove overwhelming and compromise one's ability to effectively interact with it. If validated, this hypothesis has the potential of providing unifying insights into multiple aspects of autism, with attendant benefits for improving diagnosis and therapy.

Grasping motor impairments in autism: not action planning but movement execution is deficient

Different views on the origin of deficits in action chaining in autism spectrum disorders (ASD) have been posited, ranging from functional impairments in action planning to internal models supporting motor control. Thirty-one children and adolescents with ASD and twenty-nine matched controls participated in a two-choice reach-to-grasp paradigm wherein participants received cueing information indicating either the object location or the required manner of grasping. A similar advantage for location cueing over grip cueing was found in both groups. Both accuracy and reaction times of the ASD group were indistinguishable from the control group. In contrast, movement times of the ASD group were significantly delayed in comparison with controls. These findings suggest that movement execution rather than action planning is deficient in ASD, and that deficits in action chaining derive from impairments in internal action models supporting action execution.

Verbal creativity in autism: comprehension and generation of metaphoric language in high-functioning autism spectrum disorder and typical development

Studies on creativity in participants with autism generally show impoverished performance as well as deficient comprehension of metaphoric language. However, very little is known about the ability to generate metaphors in this population. The present study examines verbal creativity in adults with autism-spectrum disorder (ASD) through tasks that rely on novel metaphoric language. Seventeen adults with ASD (mean age = 21.06) and 17 typically developing peers (mean age = 22.71) participated in the study. A multiple-choice questionnaire consisting of conventional and novel metaphors was used to test comprehension, and a sentence completion questionnaire was used to test generation of creative language. Results show similar performance in comprehension of conventional and novel metaphors in both groups, whereas adults with ASD generated more creative metaphors relative to the control group. Scores on tests of vocabulary and naming contributed to the prediction of conventional metaphor comprehension, while scores on tests of mental flexibility contributed to the prediction of novel metaphor comprehension. In addition, scores on a test of non-verbal intelligence contributed to the prediction of metaphor generation. The study points to unique verbal creativity in ASD.

Dyspraxia, motor function and visual-motor integration in autism

This project assessed dyspraxia in high-functioning school aged children with autism with a focus on Ideational Praxis. We examined the association of specific underlying motor function including eye movement with ideational dyspraxia (sequences of skilled movements) as well as the possible role of visual-motor integration in dyspraxia. We found that compared to IQ-, sex- and age-matched typically developing children, the children with autism performed significantly worse on: Ideational and Buccofacial praxis; a broad range of motor tests, including measures of simple motor skill, timing and accuracy of saccadic eye movements and motor coordination; and tests of visual-motor integration. Impairments in individual children with autism were heterogeneous in nature, although when we examined the praxis data as a function of a qualitative measure representing motor timing, we found that children with poor motor timing performed worse on all praxis categories and had slower and less accurate eye movements while those with regular timing performed as well as typical children on those same tasks. Our data provide evidence that both motor function and visual-motor integration contribute to dyspraxia. We suggest that dyspraxia in autism involves cerebellar mechanisms of movement control and the integration of these mechanisms with cortical networks implicated in praxis.

Does language guide behavior in children with autism?

It is unknown if children with high-functioning autism (HFA) employ self-directed speech to guide motor sequencing and motor control, or if they can benefit from using self-directed speech when prompted to do so. Participants performed a three-movement sequence across three conditions: Natural Learning, Task-Congruent Verbalization (TCV), and Task-Incongruent Verbalization (TIV). TIV deleteriously impacted performance in the typically-developing group (n = 22), and not the HFA group (n = 21). TCV improved performance in both groups, but to a greater extent in the HFA group. These findings suggest that children with HFA do not initiate self-directed speech spontaneously, but can use language to guide behavior when prompted to do so.

Disruption of functional organization within the primary motor cortex in children with autism

Accumulating evidence suggests that motor impairments are prevalent in autism spectrum disorder (ASD), relate to the social and communicative deficits at the core of the diagnosis and may reflect abnormal connectivity within brain networks underlying motor control and learning. Parcellation of resting-state functional connectivity data using spectral clustering approaches has been shown to be an effective means of visualizing functional organization within the brain but has most commonly been applied to explorations of normal brain function. This article presents a parcellation of a key area of the motor network, the primary motor cortex (M1), a key area of the motor control network, in adults, typically developing (TD) children and children with ASD and introduces methods for selecting the number of parcels, matching parcels across groups and testing group differences. The parcellation is based solely on patterns of connectivity between individual M1 voxels and all voxels outside of M1, and within all groups, a gross dorsomedial to ventrolateral organization emerged within M1 which was left-right symmetric. Although this gross organizational scheme was present in both groups of children, statistically significant group differences in the size and segregation of M1 parcels within regions of the motor homunculus corresponding to the upper and lower limbs were observed. Qualitative comparison of the M1 parcellation for children with ASD with that of younger and older TD children suggests that these organizational differences, with a lack of differentiation between lower limb/trunk regions and upper limb/hand regions, may be due, at least in part, to a delay in functional specialization within the motor cortex.

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

Impairments in motor functioning, which, until recently, have rarely been a primary focus in autism spectrum disorder (ASD) research, may play a key role in the early expression of biological vulnerability and be associated with key social-communication deficits. This review summarizes current knowledge of motor behavior in ASD, focusing specifically on reaching and grasping. Convergent data across the lifespan indicate that impairments to reaching and grasping emerge early in life, affect the planning and execution of motor programs, and may be impacted by additional impairments to sensory control of motor behavior. The relationship between motor impairments and diagnostic outcomes will be discussed.

The modality shift experiment in adults and children with high functioning autism

This study used the modality shift experiment, a relatively simple reaction time measure to visual and auditory stimuli, to examine attentional shifting within and across modalities in 33 children and 42 adults with high-functioning autism as compared to matched numbers of age- and ability-matched typical controls. An exaggerated "modality shift effect" relative to the TD children occurred for the children with autism in conditions involving the reaction time when shifting from sound to light but not from light to sound. No exaggerated MSE was found for the adults with autism; rather, their responses were characterized by a generalized slowness relative to the adults with TD. These results suggest a lag in maturational development in autism in basic information processing mechanisms.

Motor development in children at risk of autism: a follow-up study of infant siblings

Recently, evidence of poor or atypical motor skills in autism spectrum disorder has led some to argue that motor impairment is a core feature of the condition. The current study uses a longitudinal prospective design to assess the development of motor skills of 20 children at increased risk of developing autism spectrum disorder, who were recruited and tested at 9 and 40 months of age, on the basis of having an older sibling diagnosed with the condition. All children completed a range of motor, face processing, IQ and diagnostic assessments at a follow-up visit (aged 5-7 years), providing a detailed profile of development in this group from a number of standardised, parental report and experimental measures. A higher proportion of children than expected demonstrated motor difficulties at the follow-up visit and those highlighted by parental report as having poor motor skills as infants and toddlers were also more likely to have lower face processing scores and elevated autism-related social symptoms at 5-7 years, despite having similar IQ levels. These data lend support to the argument that early motor difficulties may be a risk factor for later motor impairment as well as differences in social communication and cognition, traits that are related to autism spectrum disorder.

A Systematic Review of the End-State Comfort Effect in Normally Developing Children and in Children With Developmental Disorders

The end-state comfort (ESC) effect signifies the tendency to avoid uncomfortable postures at the end of goal-directed movements and can be reliably observed during object manipulation in adults, but only little is known about its development in children. The aim of the present paper is to provide a review of research on the ESC effect in normally developing children and in children with various developmental disorders, and to identify the factors constraining anticipatory planning skills. Three databases (Medline, Scopus, and PubMed) and relevant journals were scrutinized and a step-wise analysis procedure was employed to identify the relevant studies. Thirteen studies assessed the ESC effect in children, ranging from 1.5–14 years of age. Nine out of these thirteen studies reported the ESC effect to be present in normally developing children, but the results are inconsistent with regard to children’s age and the kind of ESC task used. Some evidence even suggests that these planning skills are intact in children with developmental disorders. Inconsistencies between findings are discussed in the light of moderating factors like the number of action steps, precision requirements, familiarity with the task, the task procedure, motivation, sample size, and age, as well as the cognitive and motor development of the participants. Further research is needed to investigate the onset and the developmental course of ESC planning, as well as the interdependencies with other cognitive abilities and sensory-motor skills.

Statistical persistence and timing characteristics of repetitive circle drawing in children with ASD

OBJECTIVE

Standardized tests to assess movement difficulties in autism spectrum disorder (ASD) evaluate motor output, but do not provide information about underlying dynamics. The objective of this research is to study the statistical persistence and temporal dynamics of a circle drawing task in children with ASD.

METHODS

For this study 15 children diagnosed with ASD, aged 4-8 years, were asked to draw circles under various conditions using a computerized tablet. We then assessed fractal dynamics and global temporal dynamics (mean and coefficient of variation) and compared these quantities to those of typically developing (TD) controls.

RESULTS

No difference in statistical persistence was found between children with ASD and TD children. Temporal measures showed increased variability in the ASD population in the discontinuous task.

CONCLUSION

Results support the hypothesis that children with ASD have an intact ability to consistently produce continuous movements, but increased variability in production of discontinuous movements.

Motor abilities in autism: a review using a computational context

Altered motor behaviour is commonly reported in Autism Spectrum Disorder, but the aetiology remains unclear. Here, we have taken a computational approach in order to break down motor control into different components and review the functioning of each process. Our findings suggest abnormalities in two areas--poor integration of information for efficient motor planning, and increased variability in basic sensory inputs and motor outputs. In contrast, motor learning processes are relatively intact and there is inconsistent evidence for deficits in predictive control. We suggest future work on motor abilities in autism should focus on sensorimotor noise and on higher level motor planning, as these seem to have a significant role in causing motor difficulties for autistic individuals.

Sensory-motor problems in Autism

Despite being largely characterized as a social and cognitive disorder, strong evidence indicates the presence of significant sensory-motor problems in Autism Spectrum Disorder (ASD). This paper outlines our progression from initial, broad assessment using the Movement Assessment Battery for Children (M-ABC2) to subsequent targeted kinematic assessment. In particular, pronounced ASD impairment seen in the broad categories of manual dexterity and ball skills was found to be routed in specific difficulties on isolated tasks, which were translated into focused experimental assessment. Kinematic results from both subsequent studies highlight impaired use of perception-action coupling to guide, adapt and tailor movement to task demands, resulting in inflexible and rigid motor profiles. In particular difficulties with the use of temporal adaption are shown, with "hyperdexterity" witnessed in ballistic movement profiles, often at the cost of spatial accuracy and task performance. By linearly progressing from the use of a standardized assessment tool to targeted kinematic assessment, clear and defined links are drawn between measureable difficulties and underlying sensory-motor assessment. Results are specifically viewed in-light of perception-action coupling and its role in early infant development suggesting that rather than being "secondary" level impairment, sensory-motor problems may be fundamental in the progression of ASD. This logical and systematic process thus allows a further understanding into the potential root of observable motor problems in ASD; a vital step if underlying motor problems are to be considered a fundamental aspect of autism and allow a route of non-invasive preliminary diagnosis.

Choosing actions

Actions that are chosen have properties that distinguish them from actions that are not. Of the nearly infinite possible actions that can achieve any given task, many of the unchosen actions are irrelevant, incorrect, or inappropriate. Others are relevant, correct, or appropriate but are disfavored for other reasons. Our research focuses on the question of what distinguishes actions that are chosen from actions that are possible but are not. We review studies that use simple preference methods to identify factors that contribute to action choices, especially for object-manipulation tasks. We can determine which factors are especially important through simple behavioral experiments.

A review of embodiment in autism spectrum disorders

In classical approaches to cognition, sensory, motor, and emotional experiences are stripped of domain-specific perceptual and sensorimotor information, and represented in a relatively abstract form. In contrast, the embodied cognition framework suggests that our representations retain the initial imprint of the manner in which information was acquired. In this paper, we argue that individuals with autism spectrum disorders (ASD) display impairments in the temporal coordination of motor and conceptual information (as shown in gesture research) and striking deficits in the interpersonal mimicry of motor behaviors (as shown in yawning research) - findings we believe are consistent with an embodied account of ASD that includes, but goes beyond, social experiences and is driven in part by significant but subtle motor deficits. In this paper, we review the research examining an embodied cognition account of ASD, and discuss its implications.

Motor interactions with another person: do individuals with Autism Spectrum Disorder plan ahead?

Interpersonal motor interactions (joint-actions) occur on a daily basis. In joint-action situations, typically developing (TD) individuals consider the end-goal of their partner and adjust their own movements to accommodate the other person. The movement planning processes required for joint-action may, however, be difficult for individuals with an Autism Spectrum Disorder (ASD) given documented difficulties in performance on theory of mind (ToM) and motor tasks. The goal of this experiment was to determine if individuals with ASD exhibit end-state comfort behaviors similar to their TD peers in joint-action situations. Participants were asked to either pass, place, or use three common tools: a wooden toy hammer, a stick, or a calculator. These tools were selected because the degree of affordance they offer (i.e., the physical characteristics they posses to prompt proper use) ranges from direct (hammer) to indirect (calculator). Participants were asked to pass the tool to a confederate who intended to place the tool down, or use the tool. Variables of interest included beginning and end-state grip orientations of the participant and confederate (comfortable or uncomfortable) as a function of task goal, and the side to which the tool was placed or passed. Similar to Gonzalez et al. (2011), some individuals with ASD maximized their partner's beginning-state comfort by adopting personally uncomfortable postures. That said, their performance was more variable than their TD peers who consistently passed tools in a manner that facilitated comfortable use by the confederate. Therefore, the movement planning processes used to prepare to pass a tool are not stereotypical across all individuals with ASD. We propose that the novel joint-action task described herein provides the basis for testing an important link between motor performance and more complex social and communication behaviors.

Do adults with autism spectrum disorders compensate in naturalistic prospective memory tasks?

The present study is the first to directly compare event- and time-based prospective memory in Autism Spectrum Disorders (ASD) using a contextual task mirroring real life demands of prospective memory. Twenty-five individuals with ASD and 25 age- and ability-matched controls completed the Dresden Breakfast task which required participants to prepare breakfast following a set of rules and time restrictions. Overall, adults with ASD had less correct time- and event-based prospective memory responses in comparison to controls, which is consistent with previous research in children with ASD. Moreover, ASD participants completed fewer tasks, followed rules less closely, and monitored the elapsing time less closely than controls. Individuals with ASD seem not to be compensating in naturalistic prospective memory tasks.

Do planning and visual integration difficulties underpin motor dysfunction in autism? A kinematic study of young children with autism

This paper examines the upper-limb movement kinematics of young children (3-7 years) with high-functioning autism using a point-to-point movement paradigm. Consistent with prior findings in older children, a difference in movement preparation was found in the autism group (n = 11) relative to typically developing children. In contrast to typically developing children, the presence of a visual distractor in the movement task did not appear to impact on early movement planning or execution in children with autism, suggesting that this group were not considering all available environmental cues to modulate movement. The findings from this study are consistent with the possibility that autism is associated with a difficulty using visual information to prime alternative movements in a responsive way to environmental demands.

Coordination of precision grip in 2-6 years-old children with autism spectrum disorders compared to children developing typically and children with developmental disabilities

Impaired motor coordination is prevalent in children with Autism Spectrum Disorders (ASD) and affects adaptive skills. Little is known about the development of motor patterns in young children with ASD between 2 and 6 years of age. The purpose of the current study was threefold: (1) to describe developmental correlates of motor coordination in children with ASD, (2) to identify the extent to which motor coordination deficits are unique to ASD by using a control group of children with other developmental disabilities (DD), and (3) to determine the association between motor coordination variables and functional fine motor skills. Twenty-four children with ASD were compared to 30 children with typical development (TD) and 11 children with DD. A precision grip task was used to quantify and analyze motor coordination. The motor coordination variables were two temporal variables (grip to load force onset latency and time to peak grip force) and two force variables (grip force at onset of load force and peak grip force). Functional motor skills were assessed using the Fine Motor Age Equivalents of the Vineland Adaptive Behavior Scale and the Mullen Scales of Early Learning. Mixed regression models were used for all analyses. Children with ASD presented with significant motor coordination deficits only on the two temporal variables, and these variables differentiated children with ASD from the children with TD, but not from children with DD. Fine motor functional skills had no statistically significant associations with any of the motor coordination variables. These findings suggest that subtle problems in the timing of motor actions, possibly related to maturational delays in anticipatory feed-forward mechanisms, may underlie some motor deficits reported in children with ASD, but that these issues are not unique to this population. Further research is needed to investigate how children with ASD or DD compensate for motor control deficits to establish functional skills.

A review of intentional and cognitive control in autism

Different clinical studies have provided empirical evidence for impairments in cognitive control in individuals with autism spectrum disorders (ASD). The challenge arises, however, when trying to specify the neurocognitive mechanisms behind the reported observations of deviant patterns of goal-directed behavior in ASD. Studies trying to test specific assumptions by applying designs that are based on a more controlled experimental conditions often fail in providing strong evidence for an impairment in specific cognitive functions. In this review, we summarize and critically reflect on behavioral findings and their theoretical explanations regarding cognitive control processing in autism, also from a developmental perspective. The specific focus of this review is the recent evidence of deficits in intentional control – a specific subset of cognitive control processes that biases the choice of our behavioral goals – coming from different research fields. We relate this evidence to the cognitive rigidity observed in ASD and argue that individuals with ASD experience problems at the intentional level rather than at the level of implementation of intentions. Both these processes are related to cognitive control mechanisms but in different ways. Finally, we discuss new directions in studying cognitive control in ASD and how these relate to adaptive cognition.

Gesture imitation in autism I: nonsymbolic postures and sequences

This study investigated the ability of children and adolescents with autism to imitate nonsymbolic manual postures and sequences. The controls were children with receptive language delays (matched to the autistic group for age and language level), and typically developing children (matched for language level). Control tasks assessed gesture memory and manual dexterity. Imitation tasks were videotaped for blind scoring of overall accuracy and specific errors. Children with autism performed relatively poorly on posture imitation, but not imitation of simple posture sequences. Reduced manual dexterity contributed to, but did not entirely account for the autistic im itative deficit. An error that was significantly more common in the autistic group suggests that their difficulty in assuming another's perspective may be apparent at the level of simple actions.

Cognition, action, and object manipulation

Although psychology is the science of mental life and behavior, little attention has been paid to the means by which mental life is translated into behavior. One domain in which links between cognition and action have been explored is the manipulation of objects. This article reviews psychological research on this topic, with special emphasis on the tendency to grasp objects differently depending on what one plans to do with the objects. Such differential grasping has been demonstrated in a wide range of object manipulation tasks, including grasping an object in a way that reveals anticipation of the object's future orientation, height, and required placement precision. Differential grasping has also been demonstrated in a wide range of behaviors, including 1-hand grasps, 2-hand grasps, walking, and transferring objects from place to place as well as from person to person. The populations in which the tendency has been shown are also diverse, including nonhuman primates as well as human adults, children, and babies. The tendency is compromised in a variety of clinical populations and in children of a surprisingly advanced age. Verbal working memory is compromised as well if words are memorized while object manipulation tasks are performed; the recency portion of the serial position curve is reduced in this circumstance. In general, the research reviewed here points to rich connections between cognition and action as revealed through the study of object manipulation. Other implications concern affordances, Donders' law, naturalistic observation, and the teaching of psychology.

Changes in grey matter development in autism spectrum disorder

Results on grey matter (GM) structural alterations in autism spectrum disorder (ASD) are inconclusive. Moreover, little is known about age effects on brain-structure abnormalities in ASD beyond childhood. Here, we aimed to examine regional GM volumes in a large sample of children, adolescents, and adults with ASD. Magnetic resonance imaging scans were obtained in 47 male ASD subjects and 51 matched healthy controls aged 8-50 years. We used whole-brain voxel-based morphometry to first assess group differences in regional GM volume across age. Moreover, taking a cross-sectional approach, group differences in age effects on regional GM volume were investigated. Compared to controls, ASD subjects showed reduced GM volumes in the anterior cingulate cortex, posterior superior temporal sulcus, and middle temporal gyrus. Investigation of group differences in age effects on regional GM volume revealed complex, region-specific alterations in ASD. While GM volumes in the amygdala, temporoparietal junction, septal nucleus and middle cingulate cortex increased in a negative quadratic fashion in both groups, data indicated that GM volume curves in ASD subjects were shifted to the left along the age axis. Moreover, while GM volume in the right precentral gyrus decreased linearly with age in ASD individuals, GM volume development in controls followed a U-shaped pattern. Based on a large sample, our voxel-based morphometry results on group differences in regional GM volumes help to resolve inconclusive findings from previous studies in ASD. Results on age-related changes of regional GM volumes suggest that ASD is characterized by complex alterations in lifetime trajectories of several brain regions that underpin social-cognitive and motor functions.

Time-Based Prospective Memory in Children With Autism Spectrum Disorder

In this study, for the first time, prospective memory was investigated in 11 school-aged children with autism spectrum disorders and 11 matched neurotypical controls. A computerised time-based prospective memory task was embedded in a visuospatial working memory test and required participants to remember to respond to certain target times. Controls had significantly more correct prospective memory responses than the autism spectrum group. Moreover, controls checked the time more often and increased time-monitoring more steeply as the target times approached. These differences in time-checking may suggest that prospective memory in autism spectrum disorders is affected by reduced self-initiated processing as indicated by reduced task monitoring.

Atypical brain responses to reward cues in autism as revealed by event-related potentials

Social motivation deficit theories suggest that children with autism do not properly anticipate and appreciate the pleasure of social stimuli. In this study, we investigated event-related brain potentials evoked by cues that triggered social versus monetary reward anticipation in children with autism. Children with autism showed attenuated P3 activity in response to cues associated with a timely reaction to obtain a reward, irrespective of reward type. We attribute this atypical P3 activity in response to reward cues as reflective of diminished motivated attention to reward signals, a possible contributor to reduced social motivation in autism. Thus, our findings suggest a general reward processing deficit rather than a specific social reward dysfunction in autism.

Motor anticipation failure in infants with autism: a retrospective analysis of feeding situations

Previous studies on autism have shown a lack of motor anticipation in children and adults with autism. As part of a programme of research into early detection of autism, we focussed on an everyday situation: spoon-feeding. We hypothesize that an anticipation deficit may be found very early on by observing whether the baby opens his or her mouth in anticipation of the spoon’s approach. The study is based on a retrospective analysis from family home movies. Observation of infants later diagnosed with autism or an autism spectrum disorder (ASD) (n = 13) and infants with typical development (n = 14) between 4 and 6 months old show that the autism/ASD group has an early anticipation deficit.

Factors associated with driving in teens with autism spectrum disorders

OBJECTIVE

To compare the characteristics of driving and nondriving teens and explore the driving outcomes for teens with higher functioning autism spectrum disorders.

METHODS

Parents of teens aged 15 to 18 years with a parent-reported diagnosis of an autism spectrum disorder enrolled in Interactive Autism Network, an online research registry, were eligible for this cross-sectional study. An online survey was used for data collection.

RESULTS

A total of 297 parents completed the survey. Sixty-three percent of teens currently drive or plan to drive. Twenty-nine percent of the teens who are age-eligible to drive currently drive. Compared with age-eligible but nondriving teens, a greater proportion of driving teens were in full-time regular education (p < .005), planned to attend college (p < .001), and held a paid job (p = .008). A greater proportion of parents of driving teens had taught ≥1 teen to drive previously (p < .001). There were no differences in gender, autism subtype, attention deficit/hyperactivity disorder diagnosis, parental age or education, or access to public transportation. Driving predictors included individualized education plans with driving goals, indicators of functional status (classroom placement, college aspiration, and job experience), and parent experience with teaching teens to drive. Twelve percent of teens received driving citations, and 12% of teens had been involved in a motor vehicle crash.

CONCLUSIONS

Although a significant proportion of teens with higher functioning autism spectrum disorders were driving or learning to drive, the fact that most driving teens' individualized education plans did not include driving goals suggests an area of opportunity for improvement in transition planning. Driving teens were more frequently in regular education settings with college aspirations, which could help schools identify potential drivers.

Motor activity in children with autism: a review of current literature

Physical therapists have expanded their role and visibility in the treatment of children with autism spectrum disorders (ASD). Limitations in motor activity have not been considered in the assessments of core deficits of this population; however, physical therapists should be prepared to discuss and address these limitations in children with ASD.

PURPOSE

The primary purposes of this review were to summarize current evidence for motor activity limitations in children with ASD and suggest further areas of research in physical therapy and autism while considering how physical therapy may benefit children with autism.

METHOD

A literature search was carried out in 2009 and 2010 by using multiple search engines.

RESULTS

Forty-nine articles met inclusion criteria and were included in the review.

CONCLUSION

Findings indicate that limitations in motor activity may be present in individuals with ASD, and further research is needed to identify specific functional limitations.

Handwriting difficulties in children with autism spectrum disorders: a scoping review

Functional handwriting involves complex interactions among physical, cognitive and sensory systems. Impairments in many aspects of these systems are associated with Autism spectrum disorders (ASD), suggesting a heightened risk of handwriting difficulties in children with ASD. This scoping review aimed to: (1) survey the existing evidence about potential contributions to compromised handwriting function in children with ASD, and (2) map out the existing studies documenting handwriting difficulties in children with ASD. The current evidence implicates impairments in fine motor control and visual-motor integration as likely contributors to handwriting difficulties in children with ASD, though the role of the latter is not well-understood. Moreover, diminished overall legibility and compromised letter formation are emerging points of convergence among existing studies of handwriting quality in children with ASD.

Repetitive transcranial magnetic stimulation (rTMS) improves movement-related cortical potentials in autism spectrum disorders

BACKGROUND

Motor impairments are common in autism spectrum disorders (ASD). Electrophysiologic studies reveal abnormalities in the preparation of movement; repetitive transcranial magnetic stimulation (rTMS) to key motor cortical sites may therefore be a useful technique for improving motor function in ASD.

OBJECTIVE

To examine whether rTMS can improve electrophysiologic and behavioral indices of motor activity.

METHODS

Eleven participants with ASD completed three sessions in which they were administered one of three rTMS conditions (left M1, supplementary motor area [SMA], sham) at 1 Hz for 15 minutes. Movement-related cortical potentials (MRCPs) were assessed before and after rTMS.

RESULTS

rTMS to the SMA was associated with a gradient increase to the early component of MRCPs, whereas rTMS to left M1 produced a stronger gradient in the late component.

CONCLUSIONS

rTMS appears to improve movement-related electrophysiologic activity in ASD, perhaps through an influence on cortical inhibitory processes.

Beyond age and gender: relationships between cortical and subcortical brain volume and cognitive-motor abilities in school-age children

There is growing evidence that cognitive and motor functions are interrelated and may rely on the development of the same cortical and subcortical neural structures. However, no study to date has examined the relationships between brain volume, cognitive ability, and motor ability in typically developing children. The NIH MRI Study of Normal Brain Development consists of a large, longitudinal database of structural MRI and performance measures from a battery of neuropsychological assessments from typically developing children. This dataset provides a unique opportunity to examine relationships between the brain and cognitive-motor abilities. A secondary analysis was conducted on data from 172 children between the ages of 6 to 13 years with up to 2 measurement occasions (initial testing and 2-year follow-up). Linear mixed effects modeling was employed to account for age and gender effects on the development of specific cortical and subcortical volumes as well as behavioral performance measures of interest. Above and beyond the effects of age and gender, significant relationships were found between general cognitive ability (IQ) and the volume of subcortical brain structures (cerebellum and caudate) as well as spatial working memory and the putamen. In addition, IQ was found to be related to global and frontal gray matter volume as well as parietal gray and white matter. At the behavioral level, general cognitive ability was also found to be related to visuomotor ability (pegboard) and executive function (spatial working memory). These results support the notion that cognition and motor skills may be fundamentally interrelated at both the levels of behavior and brain structure.

Motor coordination in autism spectrum disorders: a synthesis and meta-analysis

Are motor coordination deficits an underlying cardinal feature of Autism Spectrum Disorders (ASD)? Database searches identified 83 ASD studies focused on motor coordination, arm movements, gait, or postural stability deficits. Data extraction involved between-group comparisons for ASD and typically developing controls (N = 51). Rigorous meta-analysis techniques including random effects models, forest and funnel plots, I (2), publication bias, fail-safe analysis, and moderator variable analyses determined a significant standardized mean difference effect equal to 1.20 (SE = 0.144; p <0.0001; Z = 10.49). This large effect indicated substantial motor coordination deficits in the ASD groups across a wide range of behaviors. The current overall findings portray motor coordination deficits as pervasive across diagnoses, thus, a cardinal feature of ASD.

Prospective and retrospective effects in human motor control: planning grasps for object rotation and translation

People pick up objects in ways that reflect prospective as well as retrospective control. Prospective control is indicated by planning for end-state comfort such that people grasp a cylinder to be rotated or translated with a hand orientation or at a height that affords a comfortable final posture. Retrospective control is indicated when people reuse a remembered grasp rather than using a new grasp that would ensure end-state comfort. Here, we asked whether these manifestations of prospective and retrospective control co-occur. We did so by having healthy young-adult participants grasp a cylinder to rotate and translate it between a horizontal position and a vertical position at each of five heights. We found that participants planned for comfortable final hand orientations for first moves but relied on recall for subsequent hand orientations. The results suggest that motor planning is sensitive to computational as well as physical demands and that object rotation and translation are not dissociable features of motor control, at least as reflected in their contributions to grasp selection. The latter result is consistent with the hypothesis that movements constitute holistic body changes between successive goal postures.

Memory for self-performed actions in individuals with Asperger syndrome

Memory for action is enhanced if individuals are allowed to perform the corresponding movements, compared to when they simply listen to them (enactment effect). Previous studies have shown that individuals with Autism Spectrum Disorders (ASD) have difficulties with processes involving the self, such as autobiographical memories and self performed actions. The present study aimed at assessing memory for action in Asperger Syndrome (AS). We investigated whether adults with AS would benefit from the enactment effect when recalling a list of previously performed items vs. items that were only visually and verbally experienced through three experimental tasks (Free Recall, Old/New Recognition and Source Memory). The results showed that while performance on Recognition and Source Memory tasks was preserved in individuals with AS, the enactment effect for self-performed actions was not consistently present, as revealed by the lower number of performed actions being recalled on the Free Recall test, as compared to adults with typical development. Subtle difficulties in encoding specific motor and proprioceptive signals during action execution in individuals with AS might affect retrieval of relevant personal episodic information. These disturbances might be associated to an impaired action monitoring system.

Factor structure of paediatric timed motor examination and its relationship with IQ

Brain systems supporting higher cognitive and motor control develop in a parallel manner, dependent on functional integrity and maturation of related regions, suggesting neighbouring neural circuitry. Concurrent examination of motor and cognitive control can provide a window into neurological development. However, identification of performance-based measures that do not correlate with IQ has been a challenge. Method Timed motor performance from the Physical and Neurological Examination of Subtle Signs and IQ were analysed in 136 children aged 6 to 16 (mean age 10y 2.6mo, SD 2y 6.4mo; 98 female, 38 male) attending an outpatient neuropsychology clinic and 136 right-handed comparison individuals aged 6 to 16 (mean age 10y 3.1mo, SD 2y 6.1mo; 98 female, 38 male). Timed activities--three repetitive movements (toe tapping, hand patting, finger tapping) and three sequenced movements (heel-toe tap, hand pronate/supinate, finger sequencing) each performed on the right and left--were included in exploratory factor analyses. Results Among comparison individuals, factor analysis yielded two factors--repetitive and sequenced movements--with the sequenced factor significantly predictive of Verbal IQ (VIQ) (DeltaR(2)=0.018, p=0.019), but not the repetitive factor (DeltaR(2)=0.004, p=0.39). Factor analysis within the clinical group yielded two similar factors (repetitive and sequenced), both significantly predictive of VIQ, (DeltaR(2)=0.028, p=0.015; DeltaR(2)=0.046, p=0.002 respectively). Interpretation Among typical children, repetitive timed tasks may be independent of IQ; however, sequenced tasks share more variance, implying shared neural substrates. Among neurologically vulnerable populations, however, both sequenced and repetitive movements covary with IQ, suggesting that repetitive speed is more indicative of underlying neurological integrity.

Motor coordination in autism spectrum disorders: a synthesis and meta-analysis

Are motor coordination deficits an underlying cardinal feature of Autism Spectrum Disorders (ASD)? Database searches identified 83 ASD studies focused on motor coordination, arm movements, gait, or postural stability deficits. Data extraction involved between-group comparisons for ASD and typically developing controls (N = 51). Rigorous meta-analysis techniques including random effects models, forest and funnel plots, I (2), publication bias, fail-safe analysis, and moderator variable analyses determined a significant standardized mean difference effect equal to 1.20 (SE = 0.144; p <0.0001; Z = 10.49). This large effect indicated substantial motor coordination deficits in the ASD groups across a wide range of behaviors. The current overall findings portray motor coordination deficits as pervasive across diagnoses, thus, a cardinal feature of ASD.