Atypical Head Movement during Face‐to‐Face Interaction in Children with Autism Spectrum Disorder

Abstract

The present study implemented an objective head pose tracking technique—OpenFace 2.0 to quantify the three dimensional head movement. Children with autism spectrum disorder (ASD) and typical development (TD) were engaged in a structured conversation with an interlocutress while wearing an eye tracker. We computed the head movement stereotypy with multiscale entropy analysis. In addition, the head rotation range (RR) and the amount of rotation per minute (ARPM) were calculated to quantify the extent of head movement. Results demonstrated that the ASD group had significantly higher level of movement stereotypy, RR and ARPM in all the three directions of head movement. Further analyses revealed that the extent of head movement could be significantly explained by movement stereotypy, but not by the amount of visual fixation to the interlocutress. These results demonstrated the atypical head movement dynamics in children with ASD during live interaction. It is proposed that head movement might potentially provide novel objective biomarkers of ASD. Lay Summary Our study used an objective tool to quantify head movement in children with autism. Results showed that children with autism had more stereotyped and greater head movement. We suggest that head movement tracking technique be widely used in autism research.

Restricted Kinematics in Children With Autism in the Execution of Complex Oscillatory Arm Movements

“…The participants of this study came from a larger research project dedicated to seeking behavioral markers of ASD from social interaction ( Zhao et al, 2021 ) and restricted behavior. The estimated sample size of this study was 34 based on data from a previous study that investigated behavioral complexity ( Fournier et al, 2014 ) by implementing power analysis (between-group t -test, d = 1, α = 0.05, power = 0.8).…”

“…Previous studies examining restricted kinematics in motor behavior have focused on the complexity of postural control and head movements in individuals with ASD ( Fournier et al, 2014 ; Li et al, 2019 ; Zhao et al, 2021 ). For instance, Fournier et al (2014) utilized multiscale entropy to quantify the complexity of postural control dynamics during quiet stance in children with ASD and age-matched TD children.…”

“…Their results demonstrated that the children with ASD exhibited a reduced level of complexity both anteroposteriorly and mediolaterally, as observed in the center of pressure (COP) data ( Fournier et al, 2014 ). Zhao et al (2021) examined the level of head movement complexity in children with ASD during a face-to-face interaction and showed an elevated stereotypy in these children as compared with the TD peers. Noticeably, all these studies adopted unintentional tasks, in which participants were not instructed how to perform movements.…”

“…Although a complex movement was performed and the time series varied at different times, Słowiński et al (2016) found that time-invariant and individual-specific kinematic properties were preserved in velocity distribution patterns, suggesting the existence of IMS. In light of this finding and given that ASD is characterized by stereotyped movement ( Fournier et al, 2014 ; Li et al, 2019 ; Zhao et al, 2021 ), we were motivated to investigate whether restrictedness would be reflected in the movement of children with ASD when performing this particular motor task.…”

“…It was later adapted to probability theory, information theory, and the theory of dynamical systems, where it is used to quantify the level of uncertainty, complexity, or irregularity ( Shannon and Shannon, 1948 ; Kolmogorov, 1959 ). Entropy analysis has been previously performed to compute the complexity of movement in individuals with ASD, and a lower entropy value indicated a higher level of restrictedness/stereotypy ( Fournier et al, 2014 ; Li et al, 2019 ; Zhao et al, 2021 ). In this study, we hypothesized that individuals with ASD would display more periodic movement patterns, and thus the entropy of amplitude and velocity would be significantly lower in ASD as compared with TD.…”