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LOUISVILLE—The autistic brain builds a stronger-than-normal association between motor commands and proprioceptive feedback, which may account for why children with autism have difficulty forming the models necessary to engage not only in motor behavior, but in social and communicative behaviors, according to research presented at the 38th National Meeting of the Child Neurology Society.
Stewart H. Mostofsky, MD, Associate Professor of Neurology at Kennedy Krieger Institute and the Johns Hopkins University School of Medicine in Baltimore, and colleagues, observed 14 children with autism spectrum disorders and 13 typically developing children as they learned to control a robotic arm. Subjects attempted to reach a target of interest while the robotic arm produced a force perpendicular to that location.
To test this hypothesis, children engaged in a second experiment in which Dr. Mostofsky’s group observed and assessed generalization, the signature of activation fields of neurons. “Generalization can tell you about how [children] learn, because you can look at the way they are able to transfer what they learn in one particular state to another,” Dr. Mostofsky said.
“The generalization patterns were strikingly different,” Dr. Mostofsky and colleagues reported. Typically developing children generalized in both proprioceptive and visual coordinates when generating models of behavior; whereas, children with autism spectrum disorders only generalized in proprioceptive coordinates, and approximately twice as strong as the typically developing children. Furthermore, the tendency to generalize in proprioceptive coordinates was highly predictive of autism-associated impairments in performance in skilled motor gestures to imitation, as well as performance of these gestures to command, and with actual tool use (often referred to as “dyspraxia”).
“[Moreover], notions of feed-forward hypotheses would suggest that these same internal models that are the basis of learning skilled movements might also be the basis for which our brain learns to understand and recognize the actions of others,” Dr. Mostofsky stated. Therefore, impaired acquisition of skill movements may contribute to the social deficits associated with autism.
Serum IL-6 Levels
Consistent with this hypothesis, generalization in intrinsic proprioceptive coordinates was highly predictive of higher (more impaired) Autism Diagnostic Observation Schedule scores for children with autism, and predictive of higher (more impaired) Social Responsiveness Scale scores for children with autism and in typically developing children, according to Dr. Mostofsky.
Dr. Mostofsky and colleagues are now examining whether these findings are specific to autism. In addition, they want to determine whether the formation of internal models of action are associated with abnormal patterns of neural connectivity. “Our preliminary diffusion tensor imaging findings do suggest that disorganization of white matter in the primary sensorimotor cortex may be associated with this increased proprioceptive bias,” Dr. Mostofsky commented.
The researchers also want to determine whether these observations can be used to modify the learning patterns in autism, either on a behavioral level, or as cortical stimulation methods used to upregulate visual-premotor connections.
—Laura Sassano
LOUISVILLE—The autistic brain builds a stronger-than-normal association between motor commands and proprioceptive feedback, which may account for why children with autism have difficulty forming the models necessary to engage not only in motor behavior, but in social and communicative behaviors, according to research presented at the 38th National Meeting of the Child Neurology Society.
Stewart H. Mostofsky, MD, Associate Professor of Neurology at Kennedy Krieger Institute and the Johns Hopkins University School of Medicine in Baltimore, and colleagues, observed 14 children with autism spectrum disorders and 13 typically developing children as they learned to control a robotic arm. Subjects attempted to reach a target of interest while the robotic arm produced a force perpendicular to that location.
To test this hypothesis, children engaged in a second experiment in which Dr. Mostofsky’s group observed and assessed generalization, the signature of activation fields of neurons. “Generalization can tell you about how [children] learn, because you can look at the way they are able to transfer what they learn in one particular state to another,” Dr. Mostofsky said.
“The generalization patterns were strikingly different,” Dr. Mostofsky and colleagues reported. Typically developing children generalized in both proprioceptive and visual coordinates when generating models of behavior; whereas, children with autism spectrum disorders only generalized in proprioceptive coordinates, and approximately twice as strong as the typically developing children. Furthermore, the tendency to generalize in proprioceptive coordinates was highly predictive of autism-associated impairments in performance in skilled motor gestures to imitation, as well as performance of these gestures to command, and with actual tool use (often referred to as “dyspraxia”).
“[Moreover], notions of feed-forward hypotheses would suggest that these same internal models that are the basis of learning skilled movements might also be the basis for which our brain learns to understand and recognize the actions of others,” Dr. Mostofsky stated. Therefore, impaired acquisition of skill movements may contribute to the social deficits associated with autism.
Serum IL-6 Levels
Consistent with this hypothesis, generalization in intrinsic proprioceptive coordinates was highly predictive of higher (more impaired) Autism Diagnostic Observation Schedule scores for children with autism, and predictive of higher (more impaired) Social Responsiveness Scale scores for children with autism and in typically developing children, according to Dr. Mostofsky.
Dr. Mostofsky and colleagues are now examining whether these findings are specific to autism. In addition, they want to determine whether the formation of internal models of action are associated with abnormal patterns of neural connectivity. “Our preliminary diffusion tensor imaging findings do suggest that disorganization of white matter in the primary sensorimotor cortex may be associated with this increased proprioceptive bias,” Dr. Mostofsky commented.
The researchers also want to determine whether these observations can be used to modify the learning patterns in autism, either on a behavioral level, or as cortical stimulation methods used to upregulate visual-premotor connections.
—Laura Sassano
LOUISVILLE—The autistic brain builds a stronger-than-normal association between motor commands and proprioceptive feedback, which may account for why children with autism have difficulty forming the models necessary to engage not only in motor behavior, but in social and communicative behaviors, according to research presented at the 38th National Meeting of the Child Neurology Society.
Stewart H. Mostofsky, MD, Associate Professor of Neurology at Kennedy Krieger Institute and the Johns Hopkins University School of Medicine in Baltimore, and colleagues, observed 14 children with autism spectrum disorders and 13 typically developing children as they learned to control a robotic arm. Subjects attempted to reach a target of interest while the robotic arm produced a force perpendicular to that location.
To test this hypothesis, children engaged in a second experiment in which Dr. Mostofsky’s group observed and assessed generalization, the signature of activation fields of neurons. “Generalization can tell you about how [children] learn, because you can look at the way they are able to transfer what they learn in one particular state to another,” Dr. Mostofsky said.
“The generalization patterns were strikingly different,” Dr. Mostofsky and colleagues reported. Typically developing children generalized in both proprioceptive and visual coordinates when generating models of behavior; whereas, children with autism spectrum disorders only generalized in proprioceptive coordinates, and approximately twice as strong as the typically developing children. Furthermore, the tendency to generalize in proprioceptive coordinates was highly predictive of autism-associated impairments in performance in skilled motor gestures to imitation, as well as performance of these gestures to command, and with actual tool use (often referred to as “dyspraxia”).
“[Moreover], notions of feed-forward hypotheses would suggest that these same internal models that are the basis of learning skilled movements might also be the basis for which our brain learns to understand and recognize the actions of others,” Dr. Mostofsky stated. Therefore, impaired acquisition of skill movements may contribute to the social deficits associated with autism.
Serum IL-6 Levels
Consistent with this hypothesis, generalization in intrinsic proprioceptive coordinates was highly predictive of higher (more impaired) Autism Diagnostic Observation Schedule scores for children with autism, and predictive of higher (more impaired) Social Responsiveness Scale scores for children with autism and in typically developing children, according to Dr. Mostofsky.
Dr. Mostofsky and colleagues are now examining whether these findings are specific to autism. In addition, they want to determine whether the formation of internal models of action are associated with abnormal patterns of neural connectivity. “Our preliminary diffusion tensor imaging findings do suggest that disorganization of white matter in the primary sensorimotor cortex may be associated with this increased proprioceptive bias,” Dr. Mostofsky commented.
The researchers also want to determine whether these observations can be used to modify the learning patterns in autism, either on a behavioral level, or as cortical stimulation methods used to upregulate visual-premotor connections.
—Laura Sassano