Children With Autism Spectrum Disorder (ASD) Process Action Imitation Differently Depending on Motor Difficulties: Implications for Individualized Therapy

PURPOSE: Autism Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized primarily by social and communication deficits. While social deficits are ASD’s hallmark, 80% of diagnosed individuals have motor deficits (Fournier et al., 2010). Imitation difficulties exhibited by those with ASD can inhibit learning as well as social and motor development (Pfeifer et al., 2008). Disparate findings have been reported in the neural networks thought to be compromised in ASD, such as the Action Observation Network (AON;Yang et al., 2016). An examination of motor skill heterogeneity in ASD may inform these aberrant findings in imitation. This study investigates how motor skills mediate AON neural processing as it relates to social and motor imitation and aims to elucidate a rationale that supports delivering individualized interventions that meet client needs as expressed through different symptom profiles present in ASD.

DESIGN: This study utilized quantitative experimental methods to compare social and motor processing among children and adolescents.

METHODS: Participants were recruited from local clinics and schools in the Los Angeles area. Eligibility criteria included: right-handedness, English fluency, and an IQ >80. Group eligibility criteria: 1) Typically developing (TD) group; no existing neurodevelopmental or psychiatric diagnosis, no evidence of motor impairment 2) ASD group; clinical diagnosis of ASD and confirmed research-qualifying scores on ASD assessments, no evidence of motor impairment 3) ASDd group; clinical diagnosis of ASD and confirmed research-qualifying scores on ASD assessments along with evidence of motor impairment. Motor ability was determined by the Movement Assessment Battery for Children (MABC-2; Henderson, 2007). ASD participants who fell below the 16% range were placed in a group labeled “ASDd,” indicating a high likelihood of comorbid dyspraxia. Those with scores at our above 16% were placed in either the ASD-only group, or in the TD group when appropriate eligibility requirements were met.

PROCEDURES: Six ASD (11.18 ± 1.24 years), eleven ASDd (12.15 ± 2.33 years), and seventeen TD (11.45 ± 1.14 years) participants underwent an fMRI scan while imitating videos of actors performing emotional (ie., happy) and non-emotional facial expressions (ie., puffing cheeks), as well as hand actions (ie., cutting paper). Between-group activation for each condition was evaluated in regions of the AON. Relationships between activation in AON and motor assessment scores were assessed using bivariate correlation.

RESULTS: Individuals with ASD without motor deficits elicited significantly less activation in the left inferior frontal gyrus compared to TD controls as well as those with motor deficits (ASDd) while imitating emotional faces (TD p=.011, ASDd p=.001) and non-emotional faces (TD p=.005, ASD p=.013). Activation while imitating emotional faces was related to motor impairment as measured by the DCDQ in the ASDd group only (R=.716, p=.004).

CONCLUSION: Preliminary results suggest that motor skills mediate imitation processing in ASD. Specifically, as motor skills improve, those with social and motor impairments (the ASDd subgroup) activate the AON more. By combining motor performance and imaging data, clinicians can identify discrete clinical ASD groups and use this classification to develop individually tailored therapies that selectively address motor and social learning skills as needed.

References

Fournier, K. A., Hass, C. J., Naik, S. K., Lodha, N. & Cauraugh, J. H. Motor coordination in autism spectrum disorders: a synthesis and meta-analysis. J Autism Dev Disord 40, 1227-1240, doi:10.1007/s10803-010-0981-3 (2010).

Henderson SE, Sugden DA, Barnett AL. Movement Assessment Battery for Children – 2 Examiner’s Manual. London: Harcourt Assessment, 2007.

Pfeifer, J. H., Iacoboni, M., Mazziotta, J. C., & Dapretto, M. (2008). Mirroring others' emotions relates to empathy and interpersonal competence in children. Neuroimage, 39(4), 2076-2085.

Yang, J., & Hofmann, J. (2016). Action observation and imitation in autism spectrum disorders: an ALE meta-analysis of fMRI studies. Brain imaging and behavior, 10(4), 960-969.