Cortical and subcortical alterations associated with precision visuomotor behavior in individuals with autism spectrum disorder

Abstract

In addition to core deficits in social-communication abilities and repetitive behaviors and interests, many 2 patients with autism spectrum disorder (ASD) experience developmental comorbidities, including 3 sensorimotor issues. Sensorimotor issues are common in ASD and associated with more severe clinical 4 symptoms. Importantly, sensorimotor behaviors are precisely quantifiable and highly translational, 5 offering promising targets for neurophysiological studies of ASD. We used functional MRI to identify 6 brain regions associated with sensorimotor behavior using a visually-guided precision gripping task in 7 individuals with ASD (N=20) and age-, IQ-, and handedness-matched controls (N=18). During 8 visuomotor behavior, individuals with ASD showed greater force variability than controls. BOLD signal 9 for multiple cortical and subcortical regions was associated with force variability, including motor and 10 premotor cortex, posterior parietal cortex, extrastriate cortex, putamen, and cerebellum. Activation in 11 right premotor cortex scaled with sensorimotor variability in controls, but not in ASD. Individuals with 12 ASD showed greater activation than controls in left putamen and left cerebellar lobule VIIb and activation 13 in these regions was associated with more severe clinically-rated symptoms of ASD. Together, these 14 results suggest that greater sensorimotor variability in ASD is associated with altered cortical-striatal 15 processes supporting action selection and cortical-cerebellar circuits involved in feedback-guided reactive 16 adjustments of motor output. Our findings also indicate that atypical organization of visuomotor cortical 17 circuits may result in heightened reliance on subcortical circuits typically dedicated to motor skill 18 acquisition. Overall, these results provide new evidence that sensorimotor alterations in ASD involve 19 aberrant cortical and subcortical organization that may contribute to key clinical issues in patients. 20 21 New and noteworthy: This is the first known study to examine functional brain activation during 22 precision visuomotor behavior in autism spectrum disorder (ASD). We replicate previous findings of 23 elevated force variability in ASD and find these deficits are associated with atypical function of ventral 24 premotor cortex, putamen, and posterolateral cerebellum, indicating cortical-striatal processes supporting 25 action selection and cortical-cerebellar circuits involved in feedback-guided reactive adjustments of motor 26 output may be key targets for understanding the neurobiology of ASD.