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Motor Abilities in Autism: A Review Using a Computational Context
Abstract
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.
... While social skill deficits are commonly acknowledged in children with ASD, motor impairments are increasingly recognized as a significant concern. Research has documented challenges in both fine and gross motor skills, as well as balance and coordination difficulties [55,81]. Studies suggest that close to 79% of children with ASD experience some form of motor difficulty [42]. ...
... However, it can also be said that sports, various movement tasks and cooperative games offer a colorful palette of opportunities for inclusion. Despite the potential in developing motor skills, research has only recently turned towards motor intervention [64,[81][82][83]. Even though motor skills are not included in the diagnostic criteria for ASD, research has demonstrated that individuals with ASD frequently exhibit deficits in both gross motor [82] and object control [83][84][85] abilities. ...
... Research on the motor skills of children with ASD have raised the question of how motor delay or limitation affects social activities or perhaps whether motor underdevelopment causes social difficulties [81]. Since our various locomotor and non-locomotor movements, i.e., both fine and gross motor movements, are essential in the interaction of social behavior, the development of motor skills is the fundamental background for ensuring social development [86]. ...
Citation: Müller, A.; Bába, É.B.; Židek, P.; Lengyel, A.; Lakó, J.H.; Laoues-Czimbalmos, N.; Molnár, A.; Boda, E. The Experiences of Motor Skill Development in Children with Autism Spectrum Disorder (ASD) Reflected through Parental Responses. Children 2024, 11, 1238.
... While social skill deficits are commonly acknowledged in children with ASD, motor impairments are increasingly recognized as a significant concern. Research has documented challenges in both fine and gross motor skills, as well as balance and coordination difficulties [55,81]. Studies suggest that close to 79% of children with ASD experience some form of motor difficulty [42]. ...
... However, it can also be said that sports, various movement tasks and cooperative games offer a colorful palette of opportunities for inclusion. Despite the potential in developing motor skills, research has only recently turned towards motor intervention [64,[81][82][83]. Even though motor skills are not included in the diagnostic criteria for ASD, research has demonstrated that individuals with ASD frequently exhibit deficits in both gross motor [82] and object control [83][84][85] abilities. ...
... Research on the motor skills of children with ASD have raised the question of how motor delay or limitation affects social activities or perhaps whether motor underdevelopment causes social difficulties [81]. Since our various locomotor and non-locomotor movements, i.e., both fine and gross motor movements, are essential in the interaction of social behavior, the development of motor skills is the fundamental background for ensuring social development [86]. ...
Background/Objectives: Understanding movement development in children with autism spectrum disorder (ASD) is critical for creating effective intervention strategies. This study aims to explore parental perspectives on the movement development of children with ASD, focusing on identifying common challenges and successful strategies. The objective is to analyze the experiences of parents to highlight the most effective approaches to support motor, communication, and social skills development in these children. Methods: Using a qualitative approach, we conducted in-depth interviews with parents of children with ASD. The data were analyzed using open and selective coding to identify key themes related to movement development challenges and strategies. The analysis included cross-referencing with the existing literature to support parental insights. Results: This study identified several key themes, including communication barriers, social interaction difficulties, and the importance of personalized movement programs. Parents reported significant challenges in understanding and addressing their children’s movement needs, particularly in group settings. However, activities such as water programs, music and dance, and animal-assisted therapies were found to be highly engaging. Motivation was a critical factor, with rewards and active parental involvement enhancing participation. Conclusions: This study highlights the crucial role of a supportive environment, including professional guidance and family support, in the success of movement development programs.
... Autism spectrum disorder (ASD) is a developmental disorder that hinders the development of social communication skills. More recently, research has shown that individuals with ASD experience difficulties in coordinating body movements [1]. In 2021, the Hong Kong General Household Survey found that the prevalence rate of ASD among students aged 15 or below in Hong Kong was 1.4%, with more than 11,000 children who were suffering from ASD locally [2]. ...
... Autistic children have been reported to exhibit varying degrees of social skill deficits, which can impact psychosocial development [3]. For example, several studies had shown that autistic children had underdeveloped social skills, which causes problems in a range of social behaviors, such as social reciprocity, social participation and social interaction [1][2][3][4][5][6][7]. Young ASD patients face additional challenges as they have difficulties in conversing their own emotional needs to others as well as understanding social cues elicited from other people [3]. ...
... It has been identified in recent studies that autistic children tend to be more socially isolated and have fewer friendships compared to their typically developing peers. This is partly because these children struggle to interpret emotions in social contexts [1]. However, through observation of interactions among various individuals, particularly between coaches and participants, it was noted that these children began to show concern for others. ...
Autism spectrum disorder (ASD) significantly affects social and motor skills development in early, middle or even late childhood. To promote social and motor skills development among autistic children, an intervention consisting of Taekwondo and elements of music therapy was designed and implemented in Hong Kong. The objective of the current study is to investigate the effectiveness of this training, based on parents’ observations of their children who had completed the key stage of the training. Thirteen parents or caregivers (n = 13) whose children with autism participated in our Taekwondo training for two months were interviewed. Three major themes were identified by thematic analysis: (A) social skills-related change after the intervention, (B) motor skills-related change after the intervention, (C) characteristics of the intervention (i.e., session arrangement, tutor/coach attitude). Our findings show that our training was perceived by parents to have a significant impact on the promotion of physical ability and social communication in autistic children.
... However, the results reported across these studies are somewhat inconsistent, leading to the generation of several theories of neuromotor control in the autistic population. Many of these theories center upon differences in sensory processing (Gowen and Hamilton, 2013;Torres et al., 2013;Baum et al., 2015) or cortico-cerebellar communication (Mostofsky et al., 2009;Mosconi et al., 2015). With substantial motor and neural heterogeneity across autistic individuals, it is possible that both theories of motor control are supported by different subsets of the autistic population (such as those with specific co-occurring conditions or cognitive profiles) or may scale with individual differences in specific behavioral, developmental, or contextual features (Insel et al., 2010). ...
... Based on previous reports of relationships between grip behavior and elements of sensorimotor network structure and function in autistic adults (Thompson et al., 2017;Lin et al., 2019;Unruh et al., 2019;Wang et al., 2019;Lepping et al., 2022; and previously reported diagnostic group differences in brain-behavior relationships across broader motor domains (Mahajan et al., 2016;, we hypothesized that autistic children would show a distinct pattern of grip-brain relationships compared to non-autistic children, even at this age range when grip strength is behaviorally similar across groups. Specifically, given the various theories of differences in sensory processing (Gowen and Hamilton, 2013;Baum et al., 2015) and cortico-cerebellar communication (Mostofsky et al., 2009;Mosconi et al., 2015) in autistic individuals, we hypothesized that autistic children would differ from non-autistic children in their associations between grip strength and the microstructural properties of the proprioception and/or cerebellar modification networks, as these networks, respectively, underlie sensory input and modification of motor commands. ...
... Specifically, grip-microstructure associations in autistic children with reduced ADHD features suggest that cerebellar feedback hinders the production of strong grip force, potentially via less reliable cerebellar-based error correction of cortical motor commands (Mosconi et al., 2015) and thus align with past work supporting cerebellar-based theories of neuromotor control in autism (Unruh et al., 2019;Wang et al., 2019;. Conversely, microstructure-grip findings in autistic children with elevated ADHD features suggest a need for increased cerebellar based signaling to detect and correct sensorimotor integration errors, potentially supporting theories of altered sensory integration in subgroups of autistic children (Gowen and Hamilton, 2013;Haar and Donchin, 2020) and aligning with past work supporting sensory-based theories of neuromotor control in autism. Together, our findings suggest that altered cerebellar signaling may differently contribute to motor behaviors in autistic children depending upon how consistent each child's behavioral profile is with ADHD features. ...
Introduction
Maximal grip strength, a measure of how much force a person’s hand can generate when squeezing an object, may be an effective method for understanding potential neurobiological differences during motor tasks. Grip strength in autistic individuals may be of particular interest due to its unique developmental trajectory. While autism-specific differences in grip-brain relationships have been found in adult populations, it is possible that such differences in grip-brain relationships may be present at earlier ages when grip strength is behaviorally similar in autistic and non-autistic groups. Further, such neural differences may lead to the later emergence of diagnostic-group grip differences in adolescence. The present study sought to examine this possibility, while also examining if grip strength could elucidate the neuro-motor sources of phenotypic heterogeneity commonly observed within autism.
Methods
Using high resolution, multi-shell diffusion, and quantitative R1 relaxometry imaging, this study examined how variations in key sensorimotor-related white matter pathways of the proprioception input, lateral grasping, cortico-cerebellar, and corticospinal networks were associated with individual variations in grip strength in 68 autistic children and 70 non-autistic (neurotypical) children (6–11 years-old).
Results
In both groups, results indicated that stronger grip strength was associated with higher proprioceptive input, lateral grasping, and corticospinal (but not cortico-cerebellar modification) fractional anisotropy and R1, indirect measures concordant with stronger microstructural coherence and increased myelination. Diagnostic group differences in these grip-brain relationships were not observed, but the autistic group exhibited more variability particularly in the cortico-cerebellar modification indices. An examination into the variability within the autistic group revealed that attention-deficit/hyperactivity disorder (ADHD) features moderated the relationships between grip strength and both fractional anisotropy and R1 relaxometry in the premotor-primary motor tract of the lateral grasping network and the cortico-cerebellar network tracts. Specifically, in autistic children with elevated ADHD features (60% of the autistic group) stronger grip strength was related to higher fractional anisotropy and R1 of the cerebellar modification network (stronger microstructural coherence and more myelin), whereas the opposite relationship was observed in autistic children with reduced ADHD features.
Discussion
Together, this work suggests that while the foundational elements of grip strength are similar across school-aged autistic and non-autistic children, neural mechanisms of grip strength within autistic children may additionally depend on the presence of ADHD features. Specifically, stronger, more coherent connections of the cerebellar modification network, which is thought to play a role in refining and optimizing motor commands, may lead to stronger grip in children with more ADHD features, weaker grip in children with fewer ADHD features, and no difference in grip in non-autistic children. While future research is needed to understand if these findings extend to other motor tasks beyond grip strength, these results have implications for understanding the biological basis of neuromotor control in autistic children and emphasize the importance of assessing co-occurring conditions when evaluating brain-behavior relationships in autism.
... It is estimated that at least 80 out of every 100 autistic individuals show poorer motor coordination compared to non-autistic individuals [6][7][8]. These motor coordination difficulties are present from infancy to adulthood [7,[9][10][11] and affect a range of movements including fine motor skills involving finger movements, eye-hand coordination such as reaching and grasping and gross motor skills such as balance and gait [9,[12][13][14]. In recent years, there has been increased acknowledgement within the research community that motor coordination difficulties are a neglected but potentially important aspect of autism [15,16]. ...
... It is estimated that at least 80 out of every 100 autistic individuals show poorer motor coordination compared to non-autistic individuals [6][7][8]. These motor coordination difficulties are present from infancy to adulthood [7,[9][10][11] and affect a range of movements including fine motor skills involving finger movements, eye-hand coordination such as reaching and grasping and gross motor skills such as balance and gait [9,[12][13][14]. In recent years, there has been increased acknowledgement within the research community that motor coordination difficulties are a neglected but potentially important aspect of autism [15,16]. ...
... Compared to children, there are relatively few studies that have examined motor coordination difficulties in autistic adults which reflects the more general situation that autistic adults are underrepresented in terms of support, diagnosis and research [30]. Quantitative studies using motor tasks coupled with sensitive measures such as motion tracking, force and button presses highlight altered movement kinematics such as increased jerkiness of arm movements [31], altered postural and gait control [12,13], slower movement and reaction times [9,11,[32][33][34][35], altered grip force control [36] and increased intraindividual variability of arm, finger and foot movements and gait [9,11,35]. Virtually nothing is known about autism in adults greater than 45 years [37], although one recent study that examined the Bruininks-Oseretsky Test of Motor Proficiency in autistic and non-autistic adults aged 40 and 60 years reported that the gap in motor coordination remains in older adulthood. ...
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.
... A burgeoning field, however, documents bodily movement and motor control differences. [3][4][5][6] These motor differences include functional challenges with both 'fine' motor tasks such as handwriting, 7-10 and 'gross' motor tasks such as riding a bike or throwing a ball. 11 Motor control difficulties in autism can also contribute to social communication challenges, including poor interpretation of autistic movements by neurotypical individuals. ...
... An interesting hypothesis here -with roots in cognitive theories of autism including weak central coherence 69 and enhanced perceptual functioning 70 that propose a preference towards local over global processing -is that autistic individuals may decompose actions into a piecemeal series of smaller individual steps. 4,44,[71][72][73][74] Importantly, our linear mixed model indicated that speed-curvature gradients, speed and submovements all predicted unique variance in jerk. Thus, atypically jerky movements in autism are likely due to multiple factors including deviations from the typical power law function as well as overall differences in mean speed, and the number of submovements that individuals execute. ...
... Group and condition were specified as categorical predictors. A random intercept for trial number (1,2,3,4,5) was fitted to account for practice or fatigue effects (e.g., speeding up as a function of trial) and a random intercept for participant (defined as a categorical predictor) was included. The following transforms were used on the data: log (speed, jerk). ...
Extant work reliably demonstrates that autistic individuals move with increased jerk (where jerk concerns change in acceleration). Although it follows that autistic movement may therefore diverge from fundamental power laws that govern movement, this hypothesis has not been directly tested to date. This lack of insight holds back progress in understanding the mechanisms underpinning differences in autism in motor control particularly with respect to movement jerkiness. Here we investigated whether movements executed by autistic adults diverged from the typical power law relationship that links movement speed and curvature. x and y position of the stylus tip was recorded at 133 Hz while 21 autistic and 19 non-autistic age-, intelligence quotient- and sex-matched adults traced, on a tablet device, a range of shapes that varied in angular frequency from 2/33 (spiral-like shapes) to 4 (square-like shapes). The gradient of the relationship between speed and curvature for each angular frequency-defined shape is reliably predicted by a set of mathematical equations often referred to as fundamental power laws thus, to assess deviations from power laws, we compared autistic and non-autistic participants in terms of speed-curvature gradients. To gain insight into potential mechanisms underpinning any differences we also used fast Fourier transform to explore amplitude spectral density across all angular frequencies. Compared to non-autistic adults, autistic adults exhibited significantly steeper speed-curvature gradients. Fast Fourier transform further revealed that non-autistic participants exhibited highly precise modulation of speed oscillations around the target frequency. For example, when drawing an ellipse their speed profile was dominated by speed changes in a band centred around the angular frequency 2 with minimal changes in other bands. Autistic adults, in contrast, exhibited less precise modulation of speed oscillations around the target frequency, a result that is reminiscent of a literature reporting broader auditory filters in autistic individuals. These results evidence, in autistic adults, a deviation from the power laws that typically govern movement and suggest differences in motor cortical control policies and/or biomechanical constraints.
... However, many studies have failed to replicate these results and challenged the broken mirror theory of autism. (Fan et al., 2010;Gowen & Hamilton, 2013;Raymaekers et al., 2009;Sotoodeh et al., , 2019. Raymaekers et al. (2009) showed that both autistic children and their NT peers exhibited mu suppression during self-execution and observed movements. ...
... broken mirror hypothesis of autism (Fan et al., 2010;Gowen & Hamilton, 2013;Raymaekers et al., 2009;Sotoodeh et al., , 2019. For example, Fan et al. (2010) found that both autistic and NT groups exhibited robust mu suppression when watching hand actions, and the magnitude of mu suppression during hand actions observation positively correlated with the communication competence of autistic individuals. ...
There has been a lot of controversy regarding mirror neuron function in autism spectrum disorder (ASD), in particular during the observation of biological motions (BM). Here, we directly explored the link between visual attention and brain activity in terms of mu suppression, by simultaneously recording eye‐tracking and EEGs during BM tasks. Nineteen autistic children (15 boys, mean age = 11.57 ± 4.28 years) and 19 age‐matched neurotypical (NT) children (15 boys, mean age = 11.68 ± 5.22 years) participated in the study. Each participant's eye movement and EEG were simultaneously recorded while watching four BM stimuli (walking, cartwheeling, free‐throwing and underarm throwing) and a scrambled condition. Mu (8–13 Hz) suppression index (SI) for central regions was calculated. Fixation counts and percent of fixation time were calculated as indices of eye movements. EEG results revealed significant mu suppressions in the central region in both groups for all BM actions. Eye‐tracking results showed that NT children had greater fixation counts and a higher percentage of fixation time than autistic children, indicating greater overall visual attention to BM. Notably, correlational analyses for both groups further revealed that individuals' fixation time and fixation counts were negatively correlated with the mu suppression index for all actions, indicating a strong association between visual attention and mu SI in the central region. Our findings suggest a critical role of visual attention in interpreting mu suppression during action perception in autism.
... Autism is characterized by persistent difficulties in social communication and social interaction across multiple contexts, including social reciprocity, nonverbal communicative behaviors used for social interaction, and skills in developing, maintaining, and understanding relationships (American Psychiatric Association, DSM-5 Task Force, 2013). Motor coordination difficulties, although not highlighted within this description of autism, are a common feature and are increasingly becoming the subject of investigation (Gowen and Hamilton, 2013;Torres and Donnellan, 2015;Bhat, 2021). Motor coordination difficulties experienced by autistic individuals are apparent from childhood and persist into adulthood and may include altered fine motor control and eye-hand coordination, as well as postural instability and general clumsiness (Fournier et al., 2010;Gowen and Hamilton, 2013;Sacrey et al., 2014;Lim et al., 2017;Morrison et al., 2018;Lum et al., 2020;Gowen et al., 2023). ...
... Motor coordination difficulties, although not highlighted within this description of autism, are a common feature and are increasingly becoming the subject of investigation (Gowen and Hamilton, 2013;Torres and Donnellan, 2015;Bhat, 2021). Motor coordination difficulties experienced by autistic individuals are apparent from childhood and persist into adulthood and may include altered fine motor control and eye-hand coordination, as well as postural instability and general clumsiness (Fournier et al., 2010;Gowen and Hamilton, 2013;Sacrey et al., 2014;Lim et al., 2017;Morrison et al., 2018;Lum et al., 2020;Gowen et al., 2023). Interest has grown in understanding how motor coordination difficulties might impact upon the social aspects of autism. ...
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.
... Additionally, autistic people often have difficulties with performing motor skills. Such movement-related features were initially reported as a general 'clumsiness' in children [4,5], yet an array of long-term issues with motor planning and execution have since been identified [6][7][8][9][10][11]. Although sensory and motor differences can contribute to significant daily living difficulties in autism, the precise mechanisms that underlie these features remain unclear. ...
... Recent neuro-computational theories have identified a variety of mechanisms that could explain atypical sensory processing [1] and movement control [8] in autism, but these theoretical accounts are yet to be adequately tested using the types of naturalistic behavioural tasks that autistic people find challenging (but see [74] for comparison of Bayesian theories of autism in a purely perceptual task). To probe the generative processes responsible, we applied a generative modelling approach to active inference behaviours from both an object lifting paradigm and an interceptive movement task. ...
Several competing neuro-computational theories of autism have emerged from predictive coding models of the brain. To disentangle their subtly different predictions about the nature of atypicalities in autistic perception, we performed computational modelling of two sensorimotor tasks: the predictive use of manual gripping forces during object lifting and anticipatory eye movements during a naturalistic interception task. In contrast to some accounts, we found no evidence of chronic atypicalities in the use of priors or weighting of sensory information during object lifting. Differences in prior beliefs, rates of belief updating, and the precision weighting of prediction errors were, however, observed for anticipatory eye movements. Most notably, we observed autism-related difficulties in flexibly adapting learning rates in response to environmental change (i.e., volatility). These findings suggest that atypical encoding of precision and context-sensitive adjustments provide a better explanation of autistic perception than generic attenuation of priors or persistently high precision prediction errors. Our results did not, however, support previous suggestions that autistic people perceive their environment to be persistently volatile.
... They reported that the autistic group performed significantly slower than the control group matched for age and IQ, suggesting reduced perception of mirror symmetry in the former. Nevertheless, the task used in this study may require more cognitive load in working memory and motor planning as well as execution skills that can be altered in autism (Gowen & Hamilton, 2013;Kercood et al., 2014), contributing to the slower performance times. On the other hand, Evers et al. (2013) used an implicit test of symmetry detection by asking autistic and non-autistic children to identify symmetrical versus asymmetrical silhouettes of everyday objects made of Gabor patches (contour detection). ...
... Considering symmetry detection thresholds between groups, we did not find evidence of reduced sensitivity to symmetry in the autistic group which is inconsistent with poorer symmetry detection in autism reported by Falter and Bailey (2011). A possible reason for this was the complexity of their task, which involved greater cognitive and motor planning, and execution demands which are known to be altered in autistic individuals (Fournier et al., 2010;Gowen & Hamilton, 2013) and would have impacted on their outcome measure of performance time. Instead, the group difference in symmetry detection in our study was driven by poorer performance in the non-autistic group at detecting symmetry with open shapes despite comparable performance for closed shapes. ...
Symmetry studies in autism are inconclusive possibly due to different types of stimuli used which depend on either local or global cues. Therefore, this study compared symmetry detection between 20 autistic and 18 non-autistic adults matched on age, IQ, gender and handedness, using contour integration tasks containing open and closed contours that rely more on local or global processing respectively. Results showed that the autistic group performed equally well with both stimuli and outperformed the non-autistic group only for the open contours, possibly due to a different strategy used in detecting symmetry. However, there were no group differences for the closed contour. Results explain discrepant findings in previous symmetry studies suggesting that symmetry tasks that favour a local strategy may be advantageous for autistic individuals. Implications of the findings towards understanding visual sensory issues in this group are discussed.
... Noteworthy, the framework emerging from our results may provide hints for a deeper understanding of both cerebellar related disturbances, and neurodevelopmental conditions such as Autism Spectrum Disorder (ASD). In general terms, both gait pattern disturbances and predictive coding anomalies have been reported in these clinical conditions [50][51][52][53] . In addition, the cerebellum has been implicated in the pathophysiology of ASD 54 , and autistic-like behaviors have been reported in cerebellar related disturbances 4 . ...
... More specifically, if-and eventually how-anomalies in using priors may impact upper or lower limb activity (e.g., does anomalous proprioceptive feedback of the terrain impact the planning of following steps ?) remains largely unexplored, although in the last decade a generic reference to motor symptoms in ASD was often reported by clinicians (Ref. 50 , but see also Ref. 62 ). ...
Beyond classical aspects related to locomotion (biomechanics), it has been hypothesized that walking pattern is influenced by a combination of distinct computations including online sensory/perceptual sampling and the processing of expectations (neuromechanics). Here, we aimed to explore the potential impact of contrasting scenarios (“risky and potentially dangerous” scenario; “safe and comfortable” scenario) on walking pattern in a group of healthy young adults. Firstly, and consistently with previous literature, we confirmed that the scenario influences gait pattern when it is recalled concurrently to participants’ walking activity (motor interference). More intriguingly, our main result showed that participants’ gait pattern is also influenced by the contextual scenario when it is evoked only before the start of walking activity (motor expectation). This condition was designed to test the impact of expectations (risky scenario vs. safe scenario) on gait pattern, and the stimulation that preceded walking activity served as prior. Noteworthy, we combined statistical and machine learning (Support-Vector Machine classifier) approaches to stratify distinct levels of analyses that explored the multi-facets architecture of walking. In a nutshell, our combined statistical and machine learning analyses converge in suggesting that walking before steps is not just a paradox.
... It is a lifelong neurodevelopmental illness depicted by insufficiencies in communication, interaction and constrained behavior [2]. Though ASD is identified mainly by behavioral and social physiognomies, autistic individuals often exhibit tainted motor ability such as reduced physical synchronization, unstable body balance and unusual posture and movement patterns [3][4][5]. Individuals with ASD show stereotypical recurring actions, constrained interests, a privation of instinct control, speech insufficiencies, compromised intellect and social skills compared to typically developing (TD) children [6]. There has been well-established work done in diagnosing ASD using kinematic physiognomies. ...
Autism spectrum condition (ASC) or autism spectrum disorder (ASD) is primarily identified with the help of behavioral indications encompassing social, sensory and motor characteristics. Although categorized, recurring motor actions are measured during diagnosis, quantifiable measures that ascertain kinematic physiognomies in the movement configurations of autistic persons are not adequately studied, hindering the advances in understanding the etiology of motor mutilation. Subject aspects such as behavioral characters that influences ASD need further exploration. Presently, limited autism datasets concomitant with screening ASD are available, and a majority of them are genetic. Hence, in this study, we used a dataset related to autism screening enveloping ten behavioral and ten personal attributes that have been effective in diagnosing ASD cases from controls in behavior science. ASD diagnosis is time exhaustive and uneconomical. The burgeoning ASD cases worldwide mandate a need for the fast and economical screening tool. Our study aimed to implement an artificial neural network with the Levenberg-Marquardt algorithm to detect ASD and examine its predictive accuracy. Consecutively, develop a clinical decision support system for early ASD identification.
... Observations of movement differences in autism spectrum disorder (ASD) date back to Kanner (1943) and Asperger (1991), who both noted motor clumsiness in their case studies. Even though the DSM-5 criteria for autism do not include motor-related features beyond repetitive motor behaviors, numerous studies have reported a wide array of motor differences, ranging from motor control/coordination, such as gait, postural planning, and anticipatory muscle activation and muscle tone (Bojanek et al., 2020;Fournier et al., 2010;Gowen & Hamilton, 2012;Jansiewicz et al., 2006;Licari et al., 2020;Miller et al., 2023;Schmitz et al., 2003), to praxis/imitation (a form of ideomotor praxis) (Lidstone & Mostofsky, 2021;Mostofsky et al., 2006;Tunçgenç et al., 2021), although others did not find such differences (Gowen & Miall, 2005;Hamilton et al., 2007;Lim et al., 2017;van Swieten et al., 2010). In addition, a different use of sensory feedback in autistic individuals has been suggested (Haswell et al., 2009;Marko et al., 2015;Stoit et al., 2013), albeit the discussion is not yet resolved (Ego et al., 2016;Takamuku et al., 2018). ...
A growing body of research reveals that autistic individuals exhibit motor coordination challenges. Multiple theoretical frameworks propose that the seemingly disparate features of autism may arise from a common underlying process: a diminished ability to make predictions. Sensorimotor skills, such as catching a ball, critically rely on predicting the ball's trajectory as well as anticipatory coordination of the entire body. Here, we assessed four different naturalistic and virtual interception tasks with 31 neurotypical and 23 autistic children (ages 7–12). In a naturalistic setting, participants caught the ball either with their hands or a hand‐held funnel with an enlarged catch area that also prevented the ball from bouncing off. A virtual setup reduced whole‐body demands, as children only moved a paddle to catch or bounce a ball on a screen. Control tasks, involving rapid reaching to grasp a static object and quiet standing, which largely eliminated the requirements for prediction, were also tested. Results from all task variations demonstrated that autistic children completed fewer successful interceptions, suggesting that predictive requirements, inherent to all interception tasks, played a critical role. Effect sizes in the virtual tasks were smaller. Correlations of the task metrics with behavioral assessments rendered the strongest correlations with Praxis scores. The control tasks showed no differences between autistic and neurotypical children. These findings lend support to the emerging hypothesis that predictive challenges are present in autism. Further research with larger sample sizes will help identify to what extent these visuomotor differences may inform core domains of autism.
... This processing style is characterized by a tendency to focus attention on specific details rather than on the overall context (Happ e & Frith, 2006;Mottron et al., 2006). Gowen and Hamilton (2013) proposed that detail-focused processing may be associated with motor planning strategies in children with ASD. Bodyrelated spatial perception in children with ASD is also thought to be affected by detail-focused processing. ...
... socialisation). In children with ID in individuals with ASD, the core symptom domains are deficits in communication and socialisation with repetitive behaviour; however, significant delays in fine and gross motor skills are also predominantly present (Bhat et al., 2011;Gowen & Hamilton, 2013;Provost et al., 2007). Early delays in motor proficiency have been strong predictors for limitations in socialisation and communication in later life in infants, children and adults with ASD (Bhat et al., 2011(Bhat et al., , 2012Linkenauger et al., 2012). ...
The aim of this review is to explore the relationship between adaptive behaviour (AB) and motor proficiency (MP). Despite AB being one of the core criteria for the diagnosis of intellectual disability, no review into the relationship between AB and MP exists. Of the 23 final studies, 19 supported a relationship between AB (composite score and/or practical, social or conceptual domains) and MP. Six studies included intellectual functioning variables, all highlighting the importance of considering both AB and intellectual functioning in relation to MP. Overall, there is evidence to support a relationship between AB and MP. More research is required of high methodological quality, in a variety of population samples and including intellectual functioning data.
... There are numerous reasons for this increasing prevalence rate such as modifying diagnostic criteria over the time and amplified associated risk factors (Anwar et al., 2018). A number of review articles, systematic reviews, and meta-analysis existed regarding various dimensions associated with ASD such as epidemiology (Fombonne, 1999), prevalence (Wing, 1993), early diagnosis of ASD (Okoye et al., 2023), neuropathology (Pickett & London, 2005), motor abilities (Gowen & Hamilton, 2013), interventions (Goldstein, 2002), and even memory (Lind, 2010). However, while there are theoretical accounts and literature reviews that characterize deficits in AM in ASD (McDonell et al., 2017;Westby, 2022), there is currently no systematic review which implements the guidelines proposed in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement (Moher et al., 2010). ...
Autism spectrum disorder (ASD) is associated with distinct deficits in communication, movement, and autobiographical memory (AM), the later one is selected for review having implications for social functioning. This systematic review synthesized empirical studies, evaluating AM in people diagnosed with ASD throughout their lifetime. This review aims to study the status of AM among individuals diagnosed with ASD. A literature search on nine electronic databases between the date of inception of each respective database and January 2023 was done. The final sample consisted of 19 studies which were analysed considering the aim of research. Before exploring the main aim, preliminary analysis also identified the measures used for ASD and AM as well as other measures used in these studies. Results revealed that individuals with ASD experienced issues in AM primarily in the form of (a) errors of omission, (b) fewer specific memories, (c) impairments in personal episodic memory but not in personal semantic memory; (d) deficits in event-specific knowledge and intact general event knowledge; and lastly the (e) role of intervention in AM was also identified. These findings highlight the nature of AM deficits among individuals with ASD and provide an avenue for targeted/tailored interventions.
... Autism spectrum disorder (ASD) is defined primarily in terms of a set of functional competencies in social settings [1]. However, it is also observed to be associated with a multiplicity of differences in sensory perception [2] and motor coordination [3][4][5][6]. To unify these observations, recent proposals have attempted to trace the defining social function symptomatology back to these more basic perceptual and sensorimotor differences [6][7][8]. ...
Recent results suggest that autistic individuals exhibit reduced accuracy compared to non-autistic peers in temporally coordinating their actions with predictable external cues, e.g., synchronizing finger taps to an auditory metronome. However, it is not yet clear whether these difficulties are driven primarily by motor differences or extend into perceptual rhythmic timing tasks. We recruited autistic and non-autistic participants for an online study testing both finger tapping synchronization and continuation as well as rhythmic time perception (anisochrony detection). We fractionated each participant's synchronization results into parameters representing error correction, motor noise, and internal time-keeper noise, and also investigated error-correcting responses to small metronome timing perturbations. Contrary to previous work, we did not find strong evidence for reduced synchronization error correction. However, we found compelling evidence for noisier internal rhythmic timekeeping in the synchronization, continuation, and perceptual components of the experiment. These results suggest that noisier internal rhythmic timing processes underlie some sensorimotor coordination challenges in autism.
... The third possibility is that processing differences may arise from atypical predictive adaptation as derived within computational accounts (Bayesian decision theory [41][42][43], relative to processing of complex or higher-level social stimuli [44][45][46] . Perceptual adaptation involves continuous (re)calibration of incoming sensory information, which match and/or update intrinsic statistics of the input 47 -and these adaptive mechanisms are believed to differ in autistic people 41,48 . Given that different talkers produce markedly different speech sounds, the listener is required to calibrate the incoming speech to the categories with the highest response probabilities 49 . ...
Accommodating talker variability is a complex and multi-layered cognitive process. It involves shifting attention to the vocal characteristics of the talker as well as the linguistic content of their speech. Due to an interdependence between voice and phonological processing, multi-talker environments typically incur additional processing costs compared to single-talker environments. A failure or inability to efficiently distribute attention over multiple acoustic cues in the speech signal may have detrimental language learning consequences. Yet, no studies have examined effects of multi-talker processing in populations with atypical perceptual, social and language processing for communication, including autistic people. Employing a classic word-monitoring task, we investigated effects of talker variability in Australian English autistic (n = 24) and non-autistic (n = 28) adults. Listeners responded to target words (e.g., apple, duck, corn) in randomised sequences of words. Half of the sequences were spoken by a single talker and the other half by multiple talkers. Results revealed that autistic participants’ sensitivity scores to accurately-spotted target words did not differ to those of non-autistic participants, regardless of whether they were spoken by a single or multiple talkers. As expected, the non-autistic group showed the well-established processing cost associated with talker variability (e.g., slower response times). Remarkably, autistic listeners’ response times did not differ across single- or multi-talker conditions, indicating they did not show perceptual processing costs when accommodating talker variability. The present findings have implications for theories of autistic perception and speech and language processing.
... Petanque is a sport that requires manipulative skill (throwing) and visual-object control where the players must toss the boules to land close to the jack for points [14]. ASD children are also found to be abnormal in two significant components which are the disability in collecting information from the environment and use it to plan for an effective motor control and interference between the input stimuli to the production of motor movement [15]. To plan a motor control movement, the individuals must utilise their cognitive skills in understanding the execution of a movement. ...
The aim of this study was to examine the effects of external focus (EF) of attention compared to internal focus (IF) of attention instructions on throwing game among the ASD children. Ten ASD children aged from seven to 10 par study. They were randomly divided into two groups (i.e., EF and IF). The EFgroup were instructed to throw the boules so that it moved in a parabolic trajectory as if they were "creating a rainbow" while the IFgroup were instructedto throw techniques, concentrating on the mechanics of the throwing arm during a two intervention. Repeated Measures ANOVA between groups and tests (pre and post) measuring the accuracy of the throws showedthe EF group performed sign the IF group in the post test. Simplified yet effective instructions could elicit effective learning among ASD children.
... These pauses in movement are interpreted to reflect greater segmentation in the movements of autistic individuals. The authors also observed greater variability in the movement profiles for the autistic group compared to the NT group, consistent with other reports (e.g., Gowen and Hamilton, 2013). ...
Introduction: Over the last decade of research, a notable connection between autism spectrum disorder (ASD) and unique motor system characteristics has been identified, which may influence social communication through distinct movement patterns. In this study, we investigated the potential for features of the broader autism phenotype to account for kinematic idiosyncrasies in social movements expressed by neurotypical individuals. Methods: Fifty-eight participants provided recordings of point-light displays expressing three basic emotions and completed the Autism Spectrum Quotient (AQ). We extracted kinematic metrics from the biological movements using computer vision and applied linear mixed-effects modeling to analyze the relationship between these kinematic metrics and AQ scores. Results: Our results revealed that individual differences in the total AQ scores, and the sub-scale scores, significantly predicted variations in kinematic metrics representing order, volume, and magnitude. Discussion: The results of this study suggest that autistic traits may intricately influence the movement expressions at the microlevel, highlighting the need for a more nuanced understanding of the potential endophenotypic characteristics associated with social movements in neurotypical individuals.
... Such difficulties in processing or integrating perceptual information may affect motor planning during voluntary movement [21,22]. Gowen and Hamilton [23] proposed that, in individuals with ASD, their detail-focused processing style might contribute to their anticipatory motor planning strategies. Several studies have shown that individuals with ASD have difficulty planning a sequence of actions to achieve a goal [24,25]. ...
Individuals with autism spectrum disorder (ASD) are more prone to injury due to falls or collisions with objects. This may be caused by impaired perceptual–motor coordination, including inaccurate body-related spatial perception and insufficient anticipatory motor planning due to a detail-focused processing style. To investigate this hypothesis, an action-selection task was developed to create conditions likely to induce collisions with obstacles and to assess perceptual accuracy and predictive attentional properties for the action selection of subsequent movements in a sequence of actions. Sixteen participants completed an autism-spectrum quotient (AQ) survey and the task. Results indicated that AQ correlated significantly with body-related spatial perception, and it was a significant predictor of the number of collisions. For the association between collisions and the eye-tracking data, results of a generalized linear mixed model showed that collisions were more likely to happen when the total fixation time to exit width was short and when the time to first fixation was late. This suggests that participants with higher autistic traits were not able to properly plan subsequent movements. Overall, these findings suggested that impaired perceptual–motor coordination, which could occur due to difficulties in perceiving body-related spatial relationships and anticipatory motor planning, may underlie the high susceptibility to injury observed in individuals with ASD.
... Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and behavioural functioning with strong expression of restricted interests and repetitive behaviour, often accompanied by unusual sensory experiences affecting an individual or multiple modalities (Diagnostic and Statistical Manual of Mental Disorders, 2013). Additionally, autism is connected with comorbid disorders and motor dysfunction, such as poor eye-hand coordination, and imbalance (Bakroon, Lakshminarayanan, 2016;Gowen, Hamilton, 2013), as well as cognitive developmental impairments or a specific cognitive style (Allman, DeLeon, Wearden, 2011;Happé, 1999). ...
b>Wprowadzenie. Rodzice dzieci z ASD doświadczają przewlekłego stresu oraz wypalenia rodzicielskiego ze względu na duże obciążenie związane z wychowaniem dziecka. Zrównoważana perspektywa temporalna stanowi zasób osobowy ułatwiający radzenie sobie z obciążeniami i stresem. Nieliczne jeszcze publikacje dostarczają danych na temat wzorca perspektyw temporalnych występującego u rodziców dzieci z ASD. Cel. Celem artykułu jest przedstawienie analizy wyników polskich badań potwierdzających specyfikę wzorców temporalnych występujących u rodziców dzieci z ASD oraz ukazanie możliwości wykorzystania terapii opartej na koncepcji perspektyw temporalnych Zimbardo dla minimalizacji objawów PTSD. Materiały i metody. W pracy zastosowano analizę danych literaturowych Wyniki. Na podstawie przeprowadzonej analizy stwierdzono, iż u rodziców dzieci z ASD częściej niż u rodziców dzieci z ZD występuje nieprzystosowawczy wzorzec perspektyw temporalnych, co może być wyznacznikiem PTSD. Wnioski. Istnieją argumenty świadczące, iż zastosowanie interwencji terapeutycznych zrealizowanych w nurcie terapii opartej na koncepcji Zimbardo może być skuteczne dla złagodzenia stresowych objawów i poprawy jakości życia rodziców dzieci z ASD.
... In ASD, motor coordination deficits are pervasive (> 80%, Bhat, 2020;Fournier et al., 2010;Licari et al., 2020;Miller et al., 2021), and specific impairments are seen in kinematics for prospective goal-directed movement, but also for gait, posture, and other aspects of motor control (Cavallo et al., 2021;Chua et al., 2022;Eggleston et al., 2017;Miller et al., 2019;Trevarthen & Delafield-Butt, 2013). Synthesis of findings suggest that general sensorimotor integration for the prospective organization of movement is disrupted, and predictive feedforward and feedback mechanisms are consistently impaired (Chua et al., 2022;David et al., 2012;Gowen & Hamilton, 2013;Sinha et al., 2014;Trevarthen & Delafield-Butt, 2013). Deficits in praxis have also been observed in ASD, including poor imitation, gesture to command, and tool use skills (Abrams et al., 2022;Kilroy et al., 2022aKilroy et al., , 2022bMostofsky et al., 2006;Roley et al., 2014). ...
Autism spectrum disorder (ASD) and Developmental Coordination Disorder (DCD) are distinct clinical groups with overlapping motor features. We attempted to (1) differentiate children with ASD from those with DCD, and from those typically developing (TD) (ages 8–17; 18 ASD, 16 DCD, 20 TD) using a 5-min coloring game on a smart tablet and (2) identify neural correlates of these differences. We utilized standardized behavioral motor assessments (e.g. fine motor, gross motor, and balance skills) and video recordings of a smart tablet task to capture any visible motor, behavioral, posture, or engagement differences. We employed machine learning analytics of motor kinematics during a 5-min coloring game on a smart tablet. Imaging data was captured using functional magnetic resonance imaging (fMRI) during action production tasks. While subject-rated motor assessments could not differentiate the two clinical groups, machine learning computational analysis provided good predictive discrimination: between TD and ASD (76% accuracy), TD and DCD (78% accuracy), and ASD and DCD (71% accuracy). Two kinematic markers which strongly drove categorization were significantly correlated with cerebellar activity. Findings demonstrate unique neuromotor patterns between ASD and DCD relate to cerebellar function and present a promising route for computational techniques in early identification. These are promising preliminary results that warrant replication with larger samples.
... *According to the CEGM evaluation score (2 or 1) at which the children were classified. and tend to move with greater acceleration and speed (Cook, Blakemore, and Press 2013;Gowen and Hamilton 2013). This analysis result reflects the effectiveness of evaluation using CEGM, which can effectively evaluate the gross motor ability of autistic children. ...
... In this piece, he reaffirmed the prevalent motor skill challenges among individuals with ASD. Following research has empirically indicated (Gowen and Hamilton, 2013) that children with ASD face delays in both fine and gross motor development, often demonstrating uncharacteristic and aberrant motor patterns. Whyatt and Craig (2012) undertook a study evaluating the factors influencing the motor capabilities of children with ASD (Whyatt and Craig, 2012). ...
Introduction
This study investigates the efficacy of sensory integration training (SIT) in enhancing balance and executive functions in children with autism spectrum disorder (ASD), with the aim of highlighting its potential for organizing and processing sensory information in the brain.
Methods
Utilizing Footscan for biomechanical evidence and functional near-infrared spectroscopy (fNIRS) for neural activation, we engaged two participant groups: a control group (n = 9) and an experimental group (n = 9). Assessments involved the Sharpened Romberg Test (SRT) for balance under varied visual conditions and the Go/No-Go task for executive function.
Results
The SIT intervention significantly improved balance function, particularly in Visual Deprivation (VD) scenarios. Neurophysiological data revealed heightened activation in the right Inferior Frontal Gyrus (R-IFG) and right Middle Frontal Gyrus (R-MFG), suggesting enhanced executive function. The potential of R-IFG/MFG activation as a reliable biomarker for assessing executive function in ASD was identified.
Discussion
The study provides empirical evidence supporting SIT’s effectiveness in enhancing balance and executive functions in children with ASD. The therapy not only improves sensory processing and motor skills but also appears to compensate for sensory deficits, particularly in vision, vestibular perception, and proprioception. Enhanced neural activation in specific PFC regions underscores SIT’s role in improving cognitive aspects, including inhibitory control and cognitive flexibility. The multidisciplinary approach adopted for this research highlights the intricate interplay between sensory-motor functions and cognitive control in ASD, paving the way for integrated therapeutic strategies. Despite these advancements, the mechanisms through which SIT exerts these multifaceted effects require further exploration.
... During sensory stimulation, postural sway increased in response to changes in sensory stimuli [18] as a result of adjustments within the PC system to maintain an upright posture [19]. Yet, children with ASD are reported to have problems in modulating sensory information and deficiencies in visual processing [20,21]. It is obvious that postural sway increased when visual information was unavailable in ASD children [22]. ...
Postural stability and control are essential motor skills for successfully performing various activities of daily living. However, children with autism spectrum disorder (ASD) exhibit significant sensorimotor impairments. The aim of this study was to investigate the efficacy of psychomotricity training on postural control (PC) of children with ASD. We recruited thirty children (age = 8.01 ± 1.2; weight = 31.66 ± 8.1 kg; height = 129.7 ± 10.8 cm) diagnosed with ASD (intellectual quotient > 50) to participate in this study. They were divided into two groups: the experimental group (n = 16) and control group (n = 14). Children in the experimental group were trained with psychomotor activities two times a week for nine weeks. Statistic postural balance was assessed before and after intervention and on different vision conditions. The results showed that the psychomotor training significantly improved PC in standing position under different conditions when compared to the control group, in all parameters (CoPA; CoPLX; CoPLy) (p < 0.01). Our preliminary findings suggest the usefulness of the psychomotor training in children with ASD on static PC.
... Specifically, attention scores in the SMN region (green arrow) are high indicating that within SMN, connectivity plays an essential role in ASD prediction. This aligns with prior studies on autism which have shown reduced FC within SMN [13], reflecting altered sensory and motor processing [20, 10,21]. Additionally, attention scores in DMN, DAN, and FPN regions were found to be high (magenta arrows) suggesting that the functional connectivity between DMN and DAN and between DMN and FPN are also crucial for ASD prediction which is in line with previous studies that report abnormalities in DMN[22] and its functional connectivity with other functional networks including DAN and FPN. ...
Autism spectrum disorder(ASD) is a lifelong neurodevelopmental condition that affects social communication and behavior. Investigating functional magnetic resonance imaging (fMRI)-based brain functional connectome can aid in the understanding and diagnosis of ASD, leading to more effective treatments. The brain is modeled as a network of brain Regions of Interest (ROIs), and ROIs form communities and knowledge of these communities is crucial for ASD diagnosis. On the one hand, Transformer-based models have proven to be highly effective across several tasks, including fMRI connectome analysis to learn useful representations of ROIs. On the other hand, existing transformer-based models treat all ROIs equally and overlook the impact of community-specific associations when learning node embeddings. To fill this gap, we propose a novel method, Com-BrainTF, a hierarchical local-global transformer architecture that learns intra and inter-community aware node embeddings for ASD prediction task. Furthermore, we avoid over-parameterization by sharing the local transformer parameters for different communities but optimize unique learnable prompt tokens for each community. Our model outperforms state-of-the-art (SOTA) architecture on ABIDE dataset and has high interpretability, evident from the attention module. Our code is available at https://github.com/ubc-tea/Com-BrainTF.
... In a recent sample of school-age children diagnosed with ASD in the United States, 87% were found to be at risk for some form of motor impairment [4]. Reported motor impairments vary from delayed gross motor skills such as motor planning [5,6], postural control [6][7][8], gait [8,9], coordination [8] and balance [8], to fine motor skills such as reaching or grasping [10]. ...
Background and aims:
Motor impairments are associated with Autism Spectrum Disorder (ASD); yet few children receive appropriate therapy. Dance interventions are known to have diverse benefits, but research is lacking in how dance can benefit those with ASD. Ballet for all Kids is a novel program that has taught recreational dance classes to those with ASD for over a decade. We aimed to analyze families' experiences in the program over many years, specifically examining why they continue to participate.
Methods and procedure:
Semi-structured interviews were conducted with 20 parents and/or legal guardians of long-term participants of Ballet for All Kids. Inductive thematic analysis was conducted to elucidate their experience in the program.
Outcomes and results:
In examining the program's retention factors, thematic analysis identified five themes: (1) authentic ballet training, (2) person centered program, (3) sensory integration and self-regulation, (4) skill development, and (5) interpersonal relationships.
Conclusions and implications:
Parents' reports add to the literature that dance can benefit participants psychologically, physically, and socially. High retention rates demonstrate the need and desire for a recreational dance program. The authenticity and individualized support of Ballet for All Kids was emphasized by parents and should inform the direction of similar programs.
Action perception, execution, and imagery share motor-cognitive processes. Given prevalent motor coordination difficulties in autism, the processes of action perception and imagery may also be altered. This study investigated whether autistic adults can engage in motor imagery by testing differences in executing, perceiving, and imagining hand movements between autistic and non-autistic adults. Twenty autistic individuals and twenty age- and IQ-matched controls completed execution, imagination, and perception tasks using a Fitts’ Law paradigm in an online session. For the execution and imagination tasks, participants performed or imagined making aiming movements between two targets. For the action perception task, participants indicated whether they could perform as accurately as the movements in presented videos. Target size and distance were manipulated into three difficulty levels and systematically varied across all tasks. Results showed a similar Fitts’ Law relationship for both groups, with significant positive correlations between movement times and difficulty level. Movement times were longest in the imagination task and shortest in the perception task for both groups. These findings suggest motor imagery processes are relatively intact in autistic adults, opening the possibility of using motor imagery as a therapy for motor coordination difficulties in autistic individuals.
O transtorno do espectro autista (TEA) é um transtorno comportamental, considerado como uma desordem neurobiológica, que leva a alterações na interação social, dificuldade na expressão, na afetividade, afetando a forma como a criança vê o mundo. Definida pela Associação Nacional de Equoterapia (ANDE) como um método terapêutico e educacional, a equoterapia utiliza-se do cavalo como recurso terapêutico e tem como objetivo o desenvolvimento biopsicossocial dos sujeitos. O objetivo deste estudo consistiu em analisar os efeitos da equoterapia no tratamento do autismo. Nesta pesquisa, 4 crianças de ambos os sexos foram avaliadas por meio da aplicação da escala M-CHAT e atendidas por meio da equoterapia. Os resultados obtidos foram satisfatórios em 75% das crianças avaliadas, demonstrando a redução da pontuação na escala M-CHAT. Diante disso, a equoterapia constitui-se uma alternativa promissora de engajamento de crianças e familiares com TEA.
Generally, participation levels of autistic children are lower than neurotypical children in social and physical activities. The range of activities that autistic children participate in is also less diverse. Building on previous qualitative work, the current research provides a quantitative perspective to explore the relationship between social skills and motor skills in autistic children, and the association with participation at home, school, and in the community. Caregivers and their 5-to-11-year-old autistic children participated in this research. Motor skills were assessed with performance-based (BOT-2-SF) and caregiver-report measures (MABC-2 checklist). Caregivers also completed questionnaires to quantify social skills (SRS-2) and participation (PEM-CY) patterns. Motor assessments were not correlated, suggesting use of the MABC-2 checklist in conjunction with the BOT-2-SF may not be well-suited for younger participants. Discordant results of proxy (i.e., social/motor skills predicted participation frequency at school, with social skills contributing to the model) and performance-based (i.e., social/motor skills predicted participation frequency at home, and average involvement in the community) reports were attributed to caregiver's focus on fine motor performance in school-based settings, considering the established link between social and fine motor skills in autism. Non-significant findings were explained by heterogeneity in social/motor skills among autistic children. Overall, while continued research is warranted, findings support a person-centered (i.e., individualized) approach to address participation of autistic children.
Context: Despite the roots of stereotypic patterns as motor behavior and pointing out some prevalent motor impairments in children with autism spectrum disorder (ASD), the assessment of motor development impairments as an introduction to the incidence of early symptoms of ASD has still been overlooked. Therefore, the present systematic review aims to assess the relationship between motor impairments and autism symptoms. Evidence Acquisition: The PubMed, Scopus, ProQuest, Google Scholar, and Web of Science databases were searched by two individuals separately using the following keywords: Autism spectrum disorder, Motor impairment, Motor delay, Fundamental movements (jumping, hopping, bounding, manipulating, chewing, and reaching objects), Gross and fine movements, Diagnosis, and Behavioral symptoms. The searches were performed within 2000 and April 2022. Results: After completing the search process, a number of 17 articles were entered into the study based on the inclusion and exclusion criteria. The articles were of low to moderate quality. Given the performed assessments, there is a significant relationship between motor impairments and behavioral symptoms in children with ASD. Conclusions: According to the present information, it can be concluded that motor impairment is possibly associated with the behavioral symptoms of ASD. Further research is required to determine the exact relationship between motor subsets and behavioral symptoms.
Importance: Motor ability plays an important role in overall developmental profiles. Preschool children with autism spectrum disorder (ASD) are at risk of motor skills deficits and delays. However, evidence of the efficacy of different motor interventions for the identification of optimal treatment types is lacking, especially for preschool children with ASD.
Objective: To examine the efficacy of the Motor Skill Occupational Therapy Intervention ON ASD (MOTION–ASD) and Cognitive Orientation Exercise (CO–EXC) programs to improve motor skills performance, self-care performance, and adaptive behaviors among preschool children with ASD.
Design: Randomized controlled trial, two-group, triple-blinded, repeated-measures design
Setting: University laboratory.
Participants: Thirteen preschool children with ASD (M age = 4.91 yr).
Outcomes and Measures: The Bruininks–Oseretsky Test of Motor Proficiency–Second Edition, Brief Form, Assessment of Motor and Process Skills, and Vineland Adaptive Behavior Scales–Third Edition.
Results: Children in the MOTION–ASD group showed significantly greater improvements in manual coordination and overall gross and fine manual skills than those in the CO–EXC group immediately after the intervention. Significant improvements in fine manual control, body coordination, overall motor skills, and self-care performance were made throughout both interventions and were retained at the posttest and the 4-wk follow-up.
Conclusions and Relevance: These findings provide supporting evidence that motor skills interventions involving fundamental skills and cognitive training may be a viable therapeutic option for treating children with ASD. The results also suggest that practitioners may consider providing structured and strategic motor skills interventions for preschool children with ASD.
What This Article Adds: This study’s rigorous tests of motor skills interventions support ways to manage motor difficulties in children with autism spectrum disorder (ASD). An intervention based on motor learning theory could benefit preschool children with ASD, especially in terms of manual coordination ability and overall gross and fine motor skills.
Autism spectrum disorder(ASD) is a lifelong neurodevelopmental condition that affects social communication and behavior. Investigating functional magnetic resonance imaging (fMRI)-based brain functional connectome can aid in the understanding and diagnosis of ASD, leading to more effective treatments. The brain is modeled as a network of brain Regions of Interest (ROIs), and ROIs form communities and knowledge of these communities is crucial for ASD diagnosis. On the one hand, Transformer-based models have proven to be highly effective across several tasks, including fMRI connectome analysis to learn useful representations of ROIs. On the other hand, existing transformer-based models treat all ROIs equally and overlook the impact of community-specific associations when learning node embeddings. To fill this gap, we propose a novel method, Com-BrainTF, a hierarchical local-global transformer architecture that learns intra and inter-community aware node embeddings for ASD prediction task. Furthermore, we avoid over-parameterization by sharing the local transformer parameters for different communities but optimize unique learnable prompt tokens for each community. Our model outperforms state-of-the-art (SOTA) architecture on ABIDE dataset and has high interpretability, evident from the attention module. Our code is available at https://github.com/ubc-tea/Com-BrainTF.
Perception, a cognitive construct, emerges through sensorimotor integration (SMI). The molecular and cellular mechanisms that shape SMI within circuits that promote cognition are poorly understood. Here, we demonstrate that expression of the autism/intellectual disability gene, Syngap1, in mouse cortical excitatory neurons promotes touch sensitivity required to elicit perceptual behaviors. Cortical Syngap1 expression enabled touch-induced feedback signals within sensorimotor loops by assembling circuits that support tactile sensitivity. These circuits also encoded correlates of attention that promoted self-generated whisker movements underlying purposeful and sustained object exploration. As Syngap1 deficient animals explored objects with whiskers, relatively weak touch signals were integrated with relatively strong motor signals. This produced a signal-to-noise deficit consistent with impaired tactile sensitivity, reduced tactile exploration, and weak tactile learning. Thus, Syngap1 expression in cortex promotes tactile perception by assembling circuits that integrate touch and whisker motor signals. Deficient Syngap1 expression likely contributes to cognitive impairment through abnormal top-down SMI.
Children with autism spectrum disorder (ASD) have cognitive difficulties and delayed development, with deficits in gross and fine motor markers as well as postural balance, leading to poorer quality of life. The objective was to evaluate mental maturity and right-left orientation in children with ASD compared to children with typical development and correlate the findings with balance and gait performance. A convenience sample composed of 21 male and female children between six years and nine years 11 months of age was submitted psychological and functional motor tests. The findings suggest correlations between mental maturity/right-left orientation and functional mobility/balance in children with autism spectrum disorder. The severity of the disorder and mental maturity were correlated with variables that demonstrated motor abnormalities, such as functional balance and gait speed.
When people meet, they almost instantaneously form an impression of each other. First impressions of character traits and rapport are less favourable when people with autism spectrum condition (ASC) are judged compared to non-autistic people. Little is known about the behavioural differences that drive these altered impressions. In the present study, we investigated the influence of interpersonal synchrony on impression formation of autistic and non-autistic people. Specifically, we used lagged cross-correlations to assess how much each interactant’s motion energy, a measure which can be determined from video recordings, influenced the other interactant’s motion energy. In short, silent clips of dyadic conversations, we asked non-autistic participants to rate their impression of one of the two interactants, which was solely based on the outlines of both interactants. We expected that the amount of leading of the target interactant, their diagnostic status as well as the interaction of these factors would influence impression formation. We found that while the amount of leading had a positive effect on the impressions of non-autistic interactants, this was not true for interactants with ASC. This suggests that interpersonal synchrony of motion energy is one driver of less favourable impressions of autistic compared to non-autistic people.
Motor impairments in children with ASD may appear early enough to serve as a marker for future inclusion in diagnostic groups. Disordered motor control may contribute to the difficulties in socialization and communication that are symptomatic of ASD. Motor delays and developmental dyspraxia can have a negative impact on activities of daily living, leisure activities, and social interactions. Several approaches and theories of motor learning and brain stimulation methods, such as transcranial direct current stimulation (tDCS) and behavioral training, are discussed in the chapter.
In this textbook it is examined in depth the undeniable relationship between cognitive and motor development and the cognitive processes involved in motor learning. Movement is a main feature of human life considering that through movement a person can explore his/her environment, show self-handling skills, expresses himself/herself through sports, arts or even movement can function as an end in itselfDue to this close interrelation between cognitive and motor development, difficulties or disorders in one area affects the other. The theories that are presented in this course book are approached in order to point out this interrelation and the development of the factors that have an effect in it (e.g. heredity–environment). The presence of difficulties or disorders influences all aspects of development in infants, children, adolescents, and later adults. People that deviate from “normal” are affected more in all aspects of development (cognitive, motor, emotional, social etc.). Motor and cognitive evaluation is valuable for professionals to understand better the weaknesses and the abilities of children, especially in those interrelated developmental components. A dynamic intervention model is suggested that considers the aforementioned relationship. The ultimate objective of this intervention model is the development (enhancement) of both knowledge and experience that will help children to scaffold his/her difficulties in everyday living (e.g. free play, playground etc.). Additionally in this textbook the best practices are presented in Developmental and Adapted Physical Education. Several activities are proposed and their aim is not exclusively the motor development but also the cognitive as the child is studied as a whole.
Evaluation of cognitive function of autistic children after early intervention has become important for providing promising biomarkers to assess the improvement after cognitive intervention. In this study, we have developed a game-based platform with electroencephalography (EEG) signal recording to investigate gaze following in children. Typically developing (TD) children and children with autism spectrum disorder (ASD) were recruited to participate in the gaze-following game with 12-channel EEG signal recording; the corresponding brain oscillations, event-related potentials (ERP), and event-related spectral perturbations were analyzed. Brain functional connections were also evaluated with phase-lag indices (PLIs). The results showed that, relative to the TD children, autistic children had smaller N170, P3a, and late positive potential (LPP) during gaze following, suggesting that they ignored low-level features of social information. Further, autistic children showed increased alpha and beta desynchronization and decreased theta synchronization and functional connectivity. With the development of human-computer interface, physiological signals are essential in future implementation of game-based interfaces to further investigate underlying mechanisms and effective biomarkers. We have demonstrated the possibility of incorporating EEG signals measured by portable applications to evaluate cognitive and social performance in autistic children. This approach has superior flexibility compared with other neuroimaging techniques.
In a novel online study, we explored whether finger tapping differences are evident in people with autistic traits in the general population. We hypothesised that those with higher autistic traits would show more impairment in finger tapping, and that age would moderate tapping output. The study included a non-diagnosed population of 159 participants aged 18–78 who completed an online measure of autistic traits (the AQ-10) and a measure of finger tapping (the FTT). Results showed those with higher AQ-10 scores recorded lower tapping scores in both hands. Moderation analysis showed younger participants with more autistic traits recorded lower tapping scores for the dominant hand. This suggests motor differences seen in autism studies are evident in the general population.
Autistic people report that their emotional expressions are sometimes misunderstood by non-autistic people. One explanation for these misunderstandings could be that the two neurotypes have different internal representations of emotion: Perhaps they have different expectations about what a facial expression showing a particular emotion looks like. In three well-powered studies with non-autistic college students in the United States (total N = 632), we investigated this possibility. In Study 1, participants recognized most facial expressions posed by autistic individuals more accurately than those posed by non-autistic individuals. Study 2 showed that one reason the autistic expressions were recognized more accurately was because they were better and more intense examples of the intended expressions than the non-autistic expressions. In Study 3, we used a set of expressions created by autistic and non-autistic individuals who could see their faces as they made the expressions, which could allow them to explicitly match the expression they produced with their internal representation of that emotional expression. Here, neither autistic expressions nor non-autistic expressions were consistently recognized more accurately. In short, these findings suggest that differences in internal representations of what emotional expressions look like are unlikely to play a major role in explaining why non-autistic people sometimes misunderstand the emotions autistic people are experiencing.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with an incidence of 1 in 68 children. Cerebellar abnormalities have been observed in many ASD patients. The cerebellum is an elaborate brain region crucially important for motor learning and coordination of movement, and increasing lines of evidence indicate that the cerebellum also contributes to emotion and cognition. In this chapter, we will review the genetic and environmental factors that may contribute to cerebellar deficits in ASD patients. Structural and functional cerebellar abnormalities based on neuroimaging and histopathological studies and current approaches to management will be discussed.
Children with a diagnosis of autism and normally developing children, matched for age and general ability, were tested on a series of visual search tasks in 2 separate experiments. The children with autism performed better than the normally developing children on difficult visual search tasks. This result occurred regardless of whether the target was uniquely defined by a single feature or a conjunction of features, as long as ceiling effects did not mask the difference. Superior visual search performance in autism can be seen as analogous to other reports of enhanced unique item detection in autism. Unique item detection in autism is discussed in the light of mechanisms proposed to be involved in normal visual search performance.
In individuals with autism or autism-spectrum-disorder (ASD), conflicting results have been reported regarding the processing of biological motion tasks. As biological motion perception and recognition might be related to impaired imitation, gross motor skills and autism specific psychopathology in individuals with ASD, we performed a functional MRI study on biological motion perception in a sample of 15 adolescent and young adult individuals with ASD and typically developing, age, sex and IQ matched controls. Neuronal activation during biological motion perception was compared between groups, and correlation patterns of imitation, gross motor and behavioral measures with neuronal activation were explored. Differences in local gray matter volume between groups as well as correlation patterns of psychopathological measures with gray matter volume were additionally compared. On the behavioral level, recognition of biological motion was assessed by a reaction time (RT) task. Groups differed strongly with regard to neuronal activation and RT, and differential correlation patterns with behavioral as well as with imitation and gross motor abilities were elicited across and within groups. However, contrasting with the initial hypothesis, additional differences between groups were observed during perception and recognition of spatially moving point lights in general irrespective of biological motion. Results either point towards difficulties in higher-order motion perception or in the integration of complex motion information in the association cortex. This interpretation is supported by differences in gray matter volume as well as correlation with repetitive behavior bilaterally in the parietal cortex and the right medial temporal cortex. The specific correlation of neuronal activation during biological motion perception with hand-finger imitation, dynamic balance and diadochokinesis abilities emphasizes the possible relevance of difficulties in biological motion perception or impaired self-other matching for action imitation and gross motor difficulties in individuals with ASD.
Cited By (since 1996):209, Export Date: 27 November 2013, Source: Scopus
Grip selection tasks have been used to test “planning” in both autism and developmental coordination disorder (DCD). We differentiate between motor and executive planning and present a modified motor planning task. Participants grasped a cylinder in 1 of 2 orientations before turning it clockwise or anticlockwise. The rotation resulted in a comfortable final posture at the cost of a harder initial reaching action on 50% of trials. We hypothesized that grip selection would be dominated by motoric developmental status. Adults were always biased towards a comfortable end-state with their dominant hand, but occasionally ended uncomfortably with their nondominant hand. Most 9- to 14-year-olds with and without autism also showed this “end-state comfort” bias but only 50% of 5- to 8-year-olds. In contrast, children with DCD were biased towards selecting the simplest initial movement. Our results are best understood in terms of motor planning, with selection of an easier initial grip resulting from poor reach-to-grasp control rather than an executive planning deficit. The absence of differences between autism and controls may reflect the low demand this particular task places on executive planning.
It is well known that you cannot tickle yourself. Here, we discuss the proposal that such attenuation of self-produced tactile stimulation is due to the sensory predictions made by an internal forward model of the motor system. A forward model predicts the sensory consequences of a movement based on the motor command. When a movement is self-produced, its sensory consequences can be accurately predicted, and this prediction can be used to attenuate the sensory effects of the movement. Studies are reviewed that demonstrate that as the discrepancy between predicted and actual sensory feedback increases during self-produced tactile stimulation there is a concomitant decrease in the level of sensory attenuation and an increase in tickliness. Functional neuroimaging studies have demonstrated that this sensory attenuation might be mediated by somatosensory cortex and anterior cingulate cortex: these areas are activated less by a self-produced tactile stimulus than by the same stimulus when it is externally produced. Furthermore, evidence suggests that the cerebellum might be involved in generating the prediction of the sensory consequences of movement. Finally, recent evidence suggests that this predictive mechanism is abnormal in patients with auditory hallucinations and/or passivity experiences. NeuroReport 11:11-16 (C) 2000 Lippincott Williams & Wilkins.
began this chapter by saying that students of action should pay more attention to the selection of macroscopic features of motor behavior—that they should develop a grammar of action as well as mechanics of action
suggested that a potentially profitable way to approach this problem is to identify constraints that the planning system uses to rule out possible movements
hypothesized that one important constraint might be avoidance of extreme joint angles
our research has shown that the planning system follows this constraint, although it also exploits extreme joint angles when they cannot be avoided (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Although the interpretation of studies of face recognition in older children, adolescents, and adults with autism is complicated by the fact that participating samples and adopted methodologies vary significantly, there is nevertheless strong evidence indicating processing peculiarities even when task performance is not deficient. Much less is known about face recognition abilities in younger children with autism. This study employed a well-normed task of face recognition to measure this ability in 102 young children with autism, pervasive developmental disorder not otherwise specified (PDDNOS), and non-PDD disorders (mental retardation and language disorders) matched on chronological age and nonverbal mental age, and in a subsample of 51 children divided equally in the same three groups matched on chronological age and verbal mental age. There were pronounced deficits of face recognition in the autistic group relative to the other nonverbally matched and verbally matched groups. Performance on two comparison tasks did not reveal significant differences when verbal ability was adequately controlled. We concluded that young children with autism have face recognition deficits that cannot be attributed to overall cognitive abilities or task demands. In contrast to controls, there was a lower correlation between performance on face recognition and nonverbal intelligence, suggesting that in autism face recognition is less correlated with general cognitive capacity. Contrary to our expectation, children with PDDNOS did not show face recognition deficits.
A model for the timing of repetitive discrete motor responses is proposed, and a prediction of negative dependency between
successive interresponse intervals is confirmed by data from a Morse key tapping task. A method that makes use of the first-order
serial correlation between interresponse intervals is used to distinguish between variance due to a timekeeping process and
variance in motor response delays subsequent to the timekeeper. These two quantities are examined as a function of mean interresponse
interval.
Important differences have emerged between introspective measures of learning, such as recall and recognition, and performance measures, in which the performance of a task is facilitated by prior experience. Introspective remembering of unattended stimuli is poor. We investigated whether performance measures would also show a strong dependence on attention. Subjects performed a serial reaction time task comprised of a repeating 10-trial stimulus sequence. When this task was given under dual-task conditions, acquisition of the sequence as assessed by verbal reports and performance measures was minimal. Patients with Korsakoff's syndrome learned the sequence despite their lack of awareness of the repeating pattern. Results are discussed in terms of the attentional requirements of learning, the relation between learning and awareness, preserved learning in amnesia, and the separation of memory systems.
To explore the specificity of impaired praxis and postural knowledge to autism by examining three samples of children, including those with autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), and typically developing (TD) children.
Twenty-four children with ASD, 24 children with ADHD, and 24 TD children, ages 8-13, completed measures assessing basic motor control (the Physical and Neurological Exam for Subtle Signs; PANESS), praxis (performance of skilled gestures to command, with imitation, and tool use) and the ability to recognize correct hand postures necessary to perform skilled gestures (the Postural Knowledge Test; PKT).
Children with ASD performed significantly worse than TD children on all three assessments. In contrast, children with ADHD performed significantly worse than TD controls on PANESS but not on the praxis examination or PKT. Furthermore, children with ASD performed significantly worse than children with ADHD on both the praxis examination and PKT, but not on the PANESS.
Whereas both children with ADHD and children with ASD show impairments in basic motor control, impairments in performance and recognition of skilled motor gestures, consistent with dyspraxia, appear to be specific to autism. The findings suggest that impaired formation of perceptual-motor action models necessary to development of skilled gestures and other goal directed behavior is specific to autism; whereas, impaired basic motor control may be a more generalized finding.
In the rubber hand illusion, perceived hand ownership can be transferred to a rubber hand after synchronous visual and tactile stimulation. Perceived body ownership and self-other relation are foundational for development of self-awareness, imitation, and empathy, which are all affected in autism spectrum disorders (ASD). We examined the rubber hand illusion in children with and without ASD. Children with ASD were initially less susceptible to the illusion than the comparison group, yet showed the effects of the illusion after 6 minutes. Delayed susceptibility to the illusion may result from atypical multisensory temporal integration and/or an unusually strong reliance on proprioception. Children with ASD who displayed less empathy were significantly less likely to experience the illusion than those with more intact ability to express empathy. A better understanding of body representation in ASD may elucidate neural underpinnings of social deficits, thus informing future intervention approaches.
Humans demonstrate a remarkable ability to generate accurate and appropriate motor behavior under many different and often uncertain environmental conditions. We previously proposed a new modular architecture, the modular selection and identification for control (MOSAIC) model, for motor learning and control based on multiple pairs of forward (predictor) and inverse (controller) models. The architecture simultaneously learns the multiple inverse models necessary for control as well as how to select the set of inverse models appropriate for a given environment. It combines both feedforward and feedback sensorimotor information so that the controllers can be selected both prior to movement and subsequently during movement. This article extends and evaluates the MOSAIC architecture in the following respects. The learning in the architecture was implemented by both the original gradient-descent method and the expectation-maximization (EM) algorithm. Unlike gradient descent, the newly derived EM algorithm is robust to the initial starting conditions and learning parameters. Second, simulations of an object manipulation task prove that the architecture can learn to manipulate multiple objects and switch between them appropriately. Moreover, after learning, the model shows generalization to novel objects whose dynamics lie within the polyhedra of already learned dynamics. Finally, when each of the dynamics is associated with a particular object shape, the model is able to select the appropriate controller before movement execution. When presented with a novel shape-dynamic pairing, inappropriate activation of modules is observed followed by on-line correction.
Recent research investigating the principles governing human perception has provided increasing evidence for probabilistic inference in human perception. For example, human auditory and visual localization judgments closely resemble that of a Bayesian causal inference observer, where the underlying causal structure of the stimuli are inferred based on both the available sensory evidence and prior knowledge. However, most previous studies have focused on characterization of perceptual inference within a static environment, and therefore, little is known about how this inference process changes when observers are exposed to a new environment. In this study we aimed to computationally characterize the change in auditory spatial perception induced by repeated auditory-visual spatial conflict, known as the ventriloquist aftereffect. In theory, this change could reflect a shift in the auditory sensory representations (i.e., shift in auditory likelihood distribution), a decrease in the precision of the auditory estimates (i.e., increase in spread of likelihood distribution), a shift in the auditory bias (i.e., shift in prior distribution), or an increase/decrease in strength of the auditory bias (i.e., the spread of prior distribution), or a combination of these. By quantitatively estimating the parameters of the perceptual process for each individual observer using a Bayesian causal inference model, we found that the shift in the perceived locations after exposure was associated with a shift in the mean of the auditory likelihood functions in the direction of the experienced visual offset. The results suggest that repeated exposure to a fixed auditory-visual discrepancy is attributed by the nervous system to sensory representation error and as a result, the sensory map of space is recalibrated to correct the error.
Multisensory perception has been the focus of intense investigation in recent years. It is now well-established that crossmodal interactions are ubiquitous in perceptual processing and endow the system with improved precision, accuracy, processing speed, etc. While these findings have shed much light on principles and mechanisms of perception, ultimately it is not very surprising that multiple sources of information provides benefits in performance compared to a single source of information. Here, we argue that the more surprising recent findings are those showing that multisensory experience also influences the subsequent unisensory processing. For example, exposure to auditory–visual stimuli can change the way that auditory or visual stimuli are processed subsequently even in isolation. We review three sets of findings that represent three different types of learning ranging from perceptual learning, to sensory recalibration, to associative learning. In all these cases exposure to multisensory stimuli profoundly influences the subsequent unisensory processing. This diversity of phenomena may suggest that continuous modification of unisensory representations by multisensory relationships may be a general learning strategy employed by the brain.
Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity and communication, as well as by repetitive behaviors and restricted interests. Unusual responses to sensory input and disruptions in the processing of both unisensory and multisensory stimuli also have been reported frequently. However, the specific aspects of sensory processing that are disrupted in ASD have yet to be fully elucidated. Recent published work has shown that children with ASD can integrate low-level audiovisual stimuli, but do so over an extended range of time when compared with typically developing (TD) children. However, the possible contributions of altered unisensory temporal processes to the demonstrated changes in multisensory function are yet unknown. In the current study, unisensory temporal acuity was measured by determining individual thresholds on visual and auditory temporal order judgment (TOJ) tasks, and multisensory temporal function was assessed through a cross-modal version of the TOJ task. Whereas no differences in thresholds for the visual TOJ task were seen between children with ASD and TD, thresholds were higher in ASD on the auditory TOJ task, providing preliminary evidence for impairment in auditory temporal processing. On the multisensory TOJ task, children with ASD showed performance improvements over a wider range of temporal intervals than TD children, reinforcing prior work showing an extended temporal window of multisensory integration in ASD. These findings contribute to a better understanding of basic sensory processing differences, which may be critical for understanding more complex social and cognitive deficits in ASD, and ultimately may contribute to more effective diagnostic and interventional strategies.
It remains unclear whether autism and Asperger's disorder (AD) exist on a symptom continuum or are separate disorders with discrete neurobiological underpinnings. In addition to impairments in communication and social cognition, motor deficits constitute a significant clinical feature in both disorders. It has been suggested that motor deficits and in particular the integrity of cerebellar modulation of movement may differentiate these disorders. We used a simple volitional saccade task to comprehensively profile the integrity of voluntary ocular motor behaviour in individuals with high functioning autism (HFA) or AD, and included measures sensitive to cerebellar dysfunction. We tested three groups of age-matched young males with normal intelligence (full scale, verbal, and performance IQ estimates >70) aged between 11 and 19 years; nine with AD, eight with HFA, and ten normally developing males as the comparison group. Overall, the metrics and dynamics of the voluntary saccades produced in this task were preserved in the AD group. In contrast, the HFA group demonstrated relatively preserved mean measures of ocular motricity with cerebellar-like deficits demonstrated in increased variability on measures of response time, final eye position, and movement dynamics. These deficits were considered to be consistent with reduced cerebellar online adaptation of movement. The results support the notion that the integrity of cerebellar modulation of movement may be different in AD and HFA, suggesting potentially differential neurobiological substrates may underpin these complex disorders.
This article reviews the behavioral literature on the control of goal-directed aiming and presents a multiple-process model of limb control. The model builds on recent variants of Woodworth's (1899) two-component model of speed-accuracy relations in voluntary movement and incorporates ideas about dynamic online limb control based on prior expectations about the efferent and afferent consequences of a planned movement. The model considers the relationship between movement speed and accuracy, and how performers adjust their trial-to-trial aiming behavior to find a safe, but fast, zone for movement execution. The model also outlines how the energy and safety costs associated with different movement outcomes contribute to movement planning processes and the control of aiming trajectories. Our theoretical position highlights the importance of advance knowledge about the sensory information that will be available for online control and the need to develop a robust internal representation of expected sensory consequences. We outline how early practice contributes to optimizing strategic planning to avoid worst-case outcomes associated with inherent neural-motor variability. Our model considers the role of both motor development and motor learning in refining feed-forward and online control. The model reconciles procedural and representational accounts of the specificity-of-learning phenomenon. Finally, we examine the breakdown of perceptual-motor precision in several special populations (i.e., Down syndrome, Williams syndrome, autism spectrum disorder, normal aging) within the framework of a multiple-process approach to goal-directed aiming.
Although autistic people have shown impairments in various learning and memory tasks, recent studies have reported mixed findings concerning implicit learning in ASD. Implicit skill learning, with its unconscious and statistical properties, underlies not only motor but also cognitive and social skills, and it therefore plays an important role from infancy to old age.
We investigated probabilistic implicit sequence learning and its consolidation in Autism Spectrum Disorder (ASD). Three groups of children participated: thirteen with high-functioning ASD, 14 age-matched controls, and 13 IQ-matched controls. All were tested on the Alternating Serial Reaction Time Task (ASRT), making it possible to separate general skill learning from sequence-specific learning. The ASRT task was repeated after 16 hours. We found that control and ASD children showed similar sequence-specific and general skill learning in the learning phase. Consolidation of skill learning and sequence-specific learning were also intact in the ASD compared to the control groups.
These results suggest that autistic children can use the effects/results of implicit learning not only for a short period, but also for a longer stretch of time. Using these findings, therapists can design more effective educational and rehabilitation programs.
The onset of crawling marks a motor, cognitive and social milestone. The present study investigated whether independent walking marks a second milestone for social behaviors. In Experiment 1, the social and exploratory behaviors of crawling infants were observed while crawling and in a baby-walker, resulting in no differences based on posture. In Experiment 2, the social behaviors of independently walking infants were compared to age-matched crawling infants in a baby-walker. Independently walking infants spent significantly more time interacting with the toys and with their mothers, and also made more vocalizations and more directed gestures compared to infants in the walker. Experiment 3 tracked infants' social behaviors longitudinally across the transition from crawling and walking. Even when controlled for age, the transition to independent walking marked increased interaction time with mothers, as well as more sophisticated interactions, including directing mothers' attention to particular objects. The results suggest a developmental progression linking social interactions with milestones in locomotor development.
Autism spectrum disorders (ASD) form a continuum of neurodevelopmental disorders, characterized by deficits in communication and reciprocal social interaction, as well as by repetitive behaviors and restricted interests. Sensory disturbances are also frequently reported in clinical and autobiographical accounts. However, surprisingly few empirical studies have characterized the fundamental features of sensory and multisensory processing in ASD. The current study is structured to test for potential differences in multisensory temporal function in ASD by making use of a temporally dependent, low-level multisensory illusion. In this illusion, the presentation of a single flash of light accompanied by multiple sounds often results in the illusory perception of multiple flashes. By systematically varying the temporal structure of the audiovisual stimuli, a "temporal window" within which these stimuli are likely to be bound into a single perceptual entity can be defined. The results of this study revealed that children with ASD report the flash-beep illusion over an extended range of stimulus onset asynchronies relative to children with typical development, suggesting that children with ASD have altered multisensory temporal function. These findings provide valuable new insights into our understanding of sensory processing in ASD and may hold promise for the development of more sensitive diagnostic measures and improved remediation strategies.
Motor control is the study of how organisms make accurate goal-directed movements. Here we consider two problems that the motor system must solve in order to achieve such control. The first problem is that sensory feedback is noisy and delayed, which can make movements inaccurate and unstable. The second problem is that the relationship between a motor command and the movement it produces is variable, as the body and the environment can both change. A solution is to build adaptive internal models of the body and the world. The predictions of these internal models, called forward models because they transform motor commands into sensory consequences, can be used to both produce a lifetime of calibrated movements, and to improve the ability of the sensory system to estimate the state of the body and the world around it. Forward models are only useful if they produce unbiased predictions. Evidence shows that forward models remain calibrated through motor adaptation: learning driven by sensory prediction errors.
Grip selection tasks have been used to test "planning" in both autism and developmental coordination disorder (DCD). We differentiate between motor and executive planning and present a modified motor planning task. Participants grasped a cylinder in 1 of 2 orientations before turning it clockwise or anticlockwise. The rotation resulted in a comfortable final posture at the cost of a harder initial reaching action on 50% of trials. We hypothesized that grip selection would be dominated by motoric developmental status. Adults were always biased towards a comfortable end-state with their dominant hand, but occasionally ended uncomfortably with their nondominant hand. Most 9- to 14-year-olds with and without autism also showed this "end-state comfort" bias but only 50% of 5- to 8-year-olds. In contrast, children with DCD were biased towards selecting the simplest initial movement. Our results are best understood in terms of motor planning, with selection of an easier initial grip resulting from poor reach-to-grasp control rather than an executive planning deficit. The absence of differences between autism and controls may reflect the low demand this particular task places on executive planning.
This study aimed to investigate the development of audiovisual integration in children with Autism Spectrum Disorder (ASD). Audiovisual integration was measured using the McGurk effect in children with ASD aged 7-16 years and typically developing children (control group) matched approximately for age, sex, nonverbal ability and verbal ability. Results showed that the children with ASD were delayed in visual accuracy and audiovisual integration compared to the control group. However, in the audiovisual integration measure, children with ASD appeared to 'catch-up' with their typically developing peers at the older age ranges. The suggestion that children with ASD show a deficit in audiovisual integration which diminishes with age has clinical implications for those assessing and treating these children.
Individuals with autism spectrum condition (ASC) have diagnostic impairments in skills that are associated with an implicit acquisition; however, it is not clear whether ASC individuals show specific implicit learning deficits. We compared ASC and typically developing (TD) individuals matched for IQ on five learning tasks: four implicit learning tasks--contextual cueing, serial reaction time, artificial grammar learning, and probabilistic classification learning tasks--that used procedures expressly designed to minimize the use of explicit strategies, and one comparison explicit learning task, paired associates learning. We found implicit learning to be intact in ASC. Beyond no evidence of differences, there was evidence of statistical equivalence between the groups on all the implicit learning tasks. This was not a consequence of compensation by explicit learning ability or IQ. Furthermore, there was no evidence to relate implicit learning to ASC symptomatology. We conclude that implicit mechanisms are preserved in ASC and propose that it is disruption by other atypical processes that impact negatively on the development of skills associated with an implicit acquisition.
Although temporal processing has received little attention in the autism literature, there are a number of reasons to suspect that people with autism spectrum disorder (ASD) may have particular difficulties judging the passage of time. The present study tested a group of 20 high-functioning adults with ASD and 20 matched comparison participants on a temporal reproduction task. The ASD group made reproductions that were significantly further from the base durations than did the comparison group. They were also more variable in their responses. Furthermore the ASD group showed particular difficulties as the base durations increased, tending to underestimate to a much greater degree than the comparison group. These findings support earlier evidence that temporal processing is impaired in ASD.
Numerous reports of elevated global motion thresholds across a variety of neurodevelopmental disorders have prompted researchers to suggest that abnormalities in global motion perception are a result of a general deficiency in the dorsal visual pathway. To test this hypothesis, we assessed the integrity of the dorsal visual pathway at lower subcortical (sensitivity to flicker contrast) and higher cortical (sensitivity to global motion) levels in children with autism, children with dyslexia, and typically developing children, of similar age and ability. While children with autism demonstrated intact lower-level, but impaired higher-level dorsal-stream functioning, children with dyslexia displayed abnormalities at both lower and higher levels of the dorsal visual stream. These findings suggest that these disorders can be dissociated according to the origin of the impairment along the dorsal-stream pathway. Implications for general cross-syndrome accounts are discussed.
Various visual cues provide information about depth and shape in a scene. When several of these cues are simultaneously available in a single location in the scene, the visual system attempts to combine them. In this paper, we discuss three key issues relevant to the experimental analysis of depth cue combination in human vision: cue promotion, dynamic weighting of cues, and robustness of cue combination. We review recent psychophysical studies of human depth cue combination in light of these issues. We organize the discussion and review as the development of a model of the depth cue combination process termed modified weak fusion (MWF). We relate the MWF framework to Bayesian theories of cue combination. We argue that the MWF model is consistent with previous experimental results and is a parsimonious summary of these results. While the MWF model is motivated by normative considerations, it is primarily intended to guide experimental analysis of depth cue combination in human vision. We describe experimental methods, analogous to perturbation analysis, that permit us to analyze depth cue combination in novel ways. In particular these methods allow us to investigate the key issues we have raised. We summarize recent experimental tests of the MWF framework that use these methods.
Autism and Asperger disorder have long been associated with movement abnormalities, although the neurobehavioural details of these abnormalities remain poorly defined. Clumsiness has traditionally been associated with Asperger disorder but not autism, although this is controversial. Others have suggested that both groups demonstrate a similar global motor delay. In this study we aimed to determine whether movement preparation or movement execution was atypical in these disorders and to describe any differences between autism and Asperger disorder. A simple motor reprogramming task was employed. The results indicated that individuals with autism and Asperger disorder have atypical movement preparation with an intact ability to execute movement. An atypical deficit in motor preparation was found in Asperger disorder, whereas movement preparation was characterized by a lack of anticipation in autism. The differences in movement preparation profiles in these disorders were suggested to reflect differential involvement of the fronto-striatal region, in particular the supplementary motor area and anterior cingulate.
