Social motor synchrony in autism spectrum conditions: A systematic review

Abstract

Some researchers suggest difficulties synchronising with a partner could underpin the social differences associated with Autism Spectrum Condition, potentially acting as a marker for autism. Social Motor Synchrony (SMS) is one aspect of synchrony that could augment observational diagnostic procedures. However, the full breadth of literature examining SMS in autism has not been systematically reviewed. A systematic review following the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines yielded 29 papers meeting inclusion criteria. Of 21 studies including a comparison group, all indicated weaker SMS between two autistic partners and in mixed-neurotype partnerships compared with two non-autistic partners. Papers involving mixed-neurotype pairs without a comparison group showed higher than chance SMS and demonstrated an increase in SMS over time following rhythm-based interventions. Although research so far demonstrates weaker SMS in pairs involving an autistic partner compared with non-autistic pairs, we identified several limitations which may have influenced SMS in autistic people and their partners. Further work is needed with autistic partnerships, more natural and preferred tasks within comfortable settings and partnerships, and more work to identify the basis of synchrony differences. We set out implications for design of further research. Lay abstract When two people interact, they often fall into sync with one another by moving their bodies at the same time. Some say autistic people are not as good as non-autistic people at moving at the same time as a partner. This has led some researchers to ask whether measuring synchrony might help diagnose autism. We reviewed the research so far to look at differences in Social Motor Synchrony (SMS) (the way we move together) between autistic people and people they interact with. The research suggests that interactions involving an autistic partner (either two autistic partners, or an autistic and non-autistic partner) show lower synchrony than a non-autistic pair. However, we recognised elements in the research so far that may have affected SMS in interactions involving an autistic person. One way SMS may have been affected in research so far might be the way interactions have been set up in the research studies. Few papers studied interactions between two autistic people or looked at synchrony in comfortable environments with autistic-preferred tasks. The studies also do not explain why synchrony might be different, or weaker, in pairs involving autistic partners. We use these limitations to suggest improvements for future research.

Evidence of mutual non-verbal synchrony in learners with severe learning disability and autism, and their support workers: a motion energy analysis study

“…Despite this, most synchrony studies have involved unfamiliar partnerships or have been situated in unfamiliar environments, such as university study centers (e.g., Fitzpatrick et al, 2017 ; Georgescu et al, 2020 ; Liu et al, 2021 ). Glass and Yuill (2023) found autistic pairs displayed similar synchrony to non-autistic pairs in carefully considered social contexts: in familiar settings and partnerships with personalized tasks. It remains unclear whether the lower synchrony previously observed in mixed pairs (e.g., Georgescu et al, 2020 ) is the result of an interpersonal mismatch, or whether this is influenced, and may be improved, by other contextual factors.…”

“… Romero et al (2018) , for instance, found higher than chance levels of synchrony between autistic children and therapists in child-led conversations. Other studies have shown that synchrony between pairs of autistic children can equal synchrony between pairs of non-autistic children when the settings and partners are familiar, and when tasks are personalized ( Glass and Yuill, 2023 ). The current results contribute to a growing body of literature challenging the idea that autistic people have impaired synchrony and demonstrate the importance of task selection in synchrony research.…”

The relationship between executive function and the association of motor coordination difficulties and social communication deficits in autistic children

“…Our mediating model of motor, EF, and social function could be partially explained by the theory of social movement synchronization (SMS) in autistic population ( 65 , 66 ), which refers to synchronous motor movements within social interaction. The motor-social relationship might be attributed to the deficit of SMS among autistic children, particularly when intentional SMS tasks were involved ( 65 ).…”

“…Our mediating model of motor, EF, and social function could be partially explained by the theory of social movement synchronization (SMS) in autistic population ( 65 , 66 ), which refers to synchronous motor movements within social interaction. The motor-social relationship might be attributed to the deficit of SMS among autistic children, particularly when intentional SMS tasks were involved ( 65 ). These intentional SMS tasks generally involve additional processing demands, such as attention, working memory and movement planning, posing challenges for autistic individuals with EF difficulties ( 67 ).…”