Motor Performance and Neural Activity of Motor Networks in Children with Autism Spectrum Disorder during Imitation of Motor Hand Actions

Background: Recent work has demonstrated that motor deficits are highly prevalent in children with Autism Spectrum Disorders (ASD) (Fournier et al, 2010; Ming, Brimacombe & Wagner, 2007). Additionally, imitation skills have been found to be significantly impaired in children with ASD (Williams et al. 2004). Previous imaging work has shown reduced neural activity in adolescents with ASD during imitation of hand gestures when compared to typically developing (TD) peers (Wadsworth et al, 2016). The mechanisms underlying this imitation deficit are unclear, though there may be a relationship between reduced motor skills and imitation impairments in ASD.

Objectives: (1) To compare performance on the Movement Assessment Battery for Children (MABC-2; Henderson, 2007) and MABC Checklist (Henderson, 2007) between a sample of TD children and children with ASD. (2) To assess how performance on these motor assessments correlate with neural activity in motor-related brain regions during an imitation task.

Methods: Data from 9 high-functioning participants with ASD (age 10.93 ± 1.86), and 15 TD participants (age 11.15± 1.39) were analyzed. The MABC-2 was administered and scored by an occupational therapist. MABC Checklist was completed by parents and scored by a research staff member. fMRI data was collected on a 3-T Siemens MAGNETOM Prisma scanner. In the scanner participants were instructed to imitate videos of hand actions (i.e., stapling paper, slicing bread) presented in a block design. Standard preprocessing and motion correction were applied, and whole brain comparisons between groups were made. Parameter estimates from motor regions (e.g., primary motor cortex) were extracted and correlated with motor skills.

Results: Two tailed t-tests showed both MABC-2 and MABC Checklist scores were significantly impaired in ASD compared with TD participants (p<.001). In the ASD group, significant correlations between MABC-2 total standard score and imitation of hand actions were found in the right precentral gyrus (r=.67, p=.04), and the left postcentral gyrus (r=.69, p=.03). However in the TD group, there were no significant correlations with MABC-2 scores and neural activity during imitation. Finally, there were no significant correlations with MABC checklist scores in either group.

Conclusions: These data suggest that in ASD, MABC-2 scores may be related to activity patterns in premotor and primary motor regions recruited during hand action imitation. This relationship is not observed in the TD group. Future directions include involving larger sample sizes, comparing to children with primary motor impairments (e.g., dyspraxia) and correlating findings with other motor and social assessments in our sample.