Bodily Expression of Social Initiation Behaviors in ASC and non-ASC children: Mixed Reality vs. LEGO Game Play

ABSTRACTThis study is part of a larger project that showed the potential of our mixed reality (MR) system in fostering social initiation behaviors in children with Autism Spectrum Condition (ASC). We compared it to a typical social intervention strategy based on construction tools, where both mediated a face-to-face dyadic play session between an ASC child and a non-ASC child. In this study, our first goal is to show that an MR platform can be utilized to alter the nonverbal body behavior between ASC and non-ASC during social interaction as much as a traditional therapy setting (LEGO). A second goal is to show how these body cues differ between ASC and non-ASC children during social initiation in these two platforms. We present our first analysis of the body cues generated under two conditions in a repeated-measures design. Body cue measurements were obtained through skeleton information and characterized in the form of spatio-temporal features from both subjects individually (e.g. distances between joints and velocities of joints), and interpersonally (e.g. proximity and visual focus of attention). We used machine learning techniques to analyze the visual data of eighteen trials of ASC and non-ASC dyads. Our experiments showed that: (i) there were differences between ASC and non-ASC bodily expressions, both at individual and interpersonal level, in LEGO and in the MR system during social initiation; (ii) the number of features indicating differences between ASC and non-ASC in terms of nonverbal behavior during initiation were higher in the MR system as compared to LEGO; and (iii) computational models evaluated with combination of these different features enabled the recognition of social initiation type (ASC or non-ASC) from body features in LEGO and in MR settings. We did not observe significant differences between the evaluated models in terms of performance for LEGO and MR environments. This might be interpreted as the MR system encouraging similar nonverbal behaviors in children, perhaps more similar than the LEGO environment, as the performance scores in the MR setting are lower as compared to the LEGO setting. These results demonstrate the potential benefits of full body interaction and MR settings for children with ASC.