Motor learning and use of visual information
Numerous lines of research have demonstrated that individuals with ASD have difficulties using visual information for planning, controlling and learning motor skills. In some cases this leads to heavy reliance on proprioception for guiding movement, and less effective use of visual information.
Haswell, C., Izawa, J., Dowell, L., Mostofsky, S., & Shadmehr, R. (2009). Representation of internal models of action in the autistic brain. Nature Neuroscience, 12(8), 970–972. http://doi.org/10.1038/nn.2356
Children with autism spectrum disorder (ASD) exhibit deficits in motor control, imitation, and social function. Does a dysfunction in the neural basis of representing internal models of action contribute to these problems? We measured patterns of generalization as children learned to control a novel tool and found that the autistic brain built a stronger than normal association between self generated motor commands and proprioceptive feedback; furthermore, the greater the reliance on proprioception, the greater the child’s impairments in social function and imitation.
Our findings demonstrate that when ASD children learn a motor task, the internal models that they form place a stronger than normal association between the self-generated motor commands with proprioception. This suggests a greater than normal dependence on cortical regions where movements are represented in intrinsic coordinates of motion (M1, somatosensory cortex), and less dependence on regions where movements are represented in extrinsic coordinates (premotor, posterior parietal). A stronger than normal association between motor commands and proprioceptive feedback may be a consequence of the fact that M1 and somatosensory cortex are nearby cortical regions, and in ASD the short-range cortical connections are over-expressed.
M.K. Marko, D. Crocetti, T. Hulst, O. Donchin, R. Shadmehr, S.H. Mostofsky Behavioural and neural basis of anomalous motor learning in children with autism Brain, 138 (2015), pp. 784–797
Summary Autism is a set of heterogeneous neurodevelopmental conditions, characterised by early-onset difficulties in social communication and unusually restricted, repetitive behaviour and interests. The worldwide population prevalence is about 1%. Autism affects more male than female individuals, and comorbidity is common (>70% have concurrent conditions). Individuals with autism have atypical cognitive profiles, such as impaired social cognition and social perception, executive dysfunction, and atypical perceptual and information processing. These profiles are underpinned by atypical neural development at the systems level. Genetics has a key role in the aetiology of autism, in conjunction with developmentally early environmental factors. Large-effect rare mutations and small-effect common variants contribute to risk. Assessment needs to be multidisciplinary and developmental, and early detection is essential for early intervention. Early comprehensive and targeted behavioural interventions can improve social communication and reduce anxiety and aggression. Drugs can reduce comorbid symptoms, but do not directly improve social communication. Creation of a supportive environment that accepts and respects that the individual is different is crucial.
Ament, K., Mejia, A., Buhlman, R., Erklin, S., Caffo, B., Mostofsky, S., & Wodka, E. (2015). Evidence for Specificity of Motor Impairments in Catching and Balance in Children with Autism. Journal of Autism and Developmental Disorders, 45(3), 742–751. http://doi.org/10.1007/s10803-014-2229-0
To evaluate evidence for motor impairment specificity in autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Children completed performance-based assessment of motor functioning (Movement Assessment Battery for Children: MABC-2). Logistic regression models were used to predict group membership. In the models comparing typically developing and developmental disability (DD), all three MABC sub-scale scores were significantly negatively associated with having a DD. In the models comparing ADHD and ASD, catching and static balance items were associated with ASD group membership, with a 1 point decrease in performance increasing odds of ASD by 36 and 39 %, respectively. Impairments in motor skills requiring the coupling of visual and temporal feedback to guide and adjust movement appear specifically deficient in ASD.
Nebel MB, Eloyan A, Nettles CA, Sweeney KL, Ament K, Ward RE, Choe AS, Barber AD, Pekar JJ, Mostofsky SH. Intrinsic Visual-Motor Synchrony Correlates With Social Deficits in Autism. Biol Psychiatry. 2016 Apr 15;79(8):633-41. doi: 10.1016/j.biopsych.2015.08.029. Epub 2015 Sep 3. PubMed PMID: 26543004; PubMed Central PMCID: PMC4777671.
BACKGROUND: Imitation, which is impaired in children with autism spectrum disorder (ASD) and critically depends on the integration of visual input with motor output, likely impacts both motor and social skill acquisition in children with ASD; however, it is unclear what brain mechanisms contribute to this impairment. Children with ASD also exhibit what appears to be an ASD-specific bias against using visual feedback during motor learning. Does the temporal congruity of intrinsic activity, or functional connectivity, between motor and visual brain regions contribute to ASD-associated deficits in imitation, motor, and social skills?
METHODS: We acquired resting-state functional magnetic resonance imaging scans from 100 8- to 12-year-old children (50 ASD). Group independent component analysis was used to estimate functional connectivity between visual and motor systems. Brain-behavior relationships were assessed by regressing functional connectivity measures with social deficit severity, imitation, and gesture performance scores.
RESULTS: We observed increased intrinsic asynchrony between visual and motor systems in children with ASD and replicated this finding in an independent sample from the Autism Brain Imaging Data Exchange. Moreover, children with more out-of-sync intrinsic visual-motor activity displayed more severe autistic traits, while children with greater intrinsic visual-motor synchrony were better imitators.
CONCLUSIONS: Our twice replicated findings confirm that visual-motor functional connectivity is disrupted in ASD. Furthermore, the observed temporal incongruity between visual and motor systems, which may reflect diminished integration of visual consequences with motor output, was predictive of the severity of social deficits and may contribute to impaired social-communicative skill development in children with ASD.
Sharer EA, Mostofsky SH, Pascual-Leone A, Oberman LM. Isolating Visual and Proprioceptive Components of Motor Sequence Learning in ASD. Autism Res. 2015 Oct 7. doi: 10.1002/aur.1537. [Epub ahead of print] PubMed PMID: 26442448.
In addition to defining impairments in social communication skills, individuals with autism spectrum disorder (ASD) also show impairments in more basic sensory and motor skills. Development of new skills involves integrating information from multiple sensory modalities. This input is then used to form internal models of action that can be accessed when both performing skilled movements, as well as understanding those actions performed by others. Learning skilled gestures is particularly reliant on integration of visual and proprioceptive input. We used a modified serial reaction time task (SRTT) to decompose proprioceptive and visual components and examine whether patterns of implicit motor skill learning differ in ASD participants as compared with healthy controls. While both groups learned the implicit motor sequence during training, healthy controls showed robust generalization whereas ASD participants demonstrated little generalization when visual input was constant. In contrast, no group differences in generalization were observed when proprioceptive input was constant, with both groups showing limited degrees of generalization. The findings suggest, when learning a motor sequence, individuals with ASD tend to rely less on visual feedback than do healthy controls. Visuomotor representations are considered to underlie imitative learning and action understanding and are thereby crucial to social skill and cognitive development. Thus, anomalous patterns of implicit motor learning, with a tendency to discount visual feedback, may be an important contributor in core social communication deficits that characterize ASD.
Sharer E, Crocetti D, Muschelli J, Barber AD, Nebel MB, Caffo BS, Pekar JJ, Mostofsky SH. Neural Correlates of Visuomotor Learning in Autism. J Child Neurol. 2015 Dec;30(14):1877-86. doi: 10.1177/0883073815600869. Epub 2015 Sep 8. PubMed PMID: 26350725.
Motor impairments are prevalent in children with autism spectrum disorder. The Serial Reaction Time Task, a well-established visuomotor sequence learning probe, has produced inconsistent behavioral findings in individuals with autism. Moreover, it remains unclear how underlying neural processes for visuomotor learning in children with autism compare to processes for typically developing children. Neural activity differences were assessed using functional magnetic resonance imaging during a modified version of the Serial Reaction Time Task in children with and without autism. Though there was no group difference in visuomotor sequence learning, underlying patterns of neural activation significantly differed when comparing sequence (i.e., learning) to random (i.e., nonlearning) blocks. Children with autism demonstrated decreased activity in brain regions implicated in visuomotor sequence learning: superior temporal sulcus and posterior cingulate cortex. The findings implicate differences in brain mechanisms that support initial sequence learning in autism and can help explain behavioral observations of autism-associated impairments in skill development (motor, social, communicative) reliant on visuomotor integration.
Motor planning is affected by emotional valence of task
Longuet S, Ferrel-Chapus C, Orêve MJ, Chamot JM, Vernazza-Martin S. Emotion, intent and voluntary movement in children with autism. An example: the goal directed locomotion. J Autism Dev Disord. 2012 Jul;42(7):1446-58. doi: 10.1007/s10803-011-1383-x. PubMed PMID: 22038289.
This article focuses on the impact of intentionality on goal directed locomotion in healthy and autistic children. Closely linked with emotions and motivation, it is directly connected with movement planning. Is planning only preserved when the goal of the action appears motivating for healthy and autistic children? Is movement programming similar for autistic and healthy children, and does it vary according to the emotional valence of the object? Moving in a straight line, twenty autistic and healthy children had to retrieve a positive or aversive emotional valence object. The results suggest planning and programming are preserved in an emotionally positive situation. However, in an aversive situation, autistic children appear to have a deficit in terms of planning and sometimes programming.