Research in imitation, social communication, and gestural processing
As the number of individuals worldwide diagnosed as being on the autism spectrum increases every year (Center for Disease Control, 2018), researchers are striving to meet the needs of this growing population. Recent trends in the field of autism require cross-disciplinary research and extensive collaboration on multiple levels, integrating areas including developmental psychology, neuropsychology, psycholinguistics, and education. A major challenge in achieving successful outcomes and meeting the educational demands is the heterogeneity of the population; ranging from individuals who are preverbal or those who may never acquire functional speech, to individuals who are struggling to survive in traditional society but who have skills and talents to bring to the workplace.
Autism occurs along a continuum, and the differences in functional outcomes among autistic individuals are striking. Therefore, implementing research programs pinpointing significant predictors of long-term success and positive functional outcomes in autistic individuals is essential. Despite the heterogeneity of this population, core challenges are evident in individuals across the spectrum, and identifying a possible weakness that may be implicated in the sequelae of social interaction and communicative difficulties would pose a logical starting point for an innovative approach.
The ability to imitate is an early and important developmental milestone that continues throughout the lifespan (Metzloff & Moore, 1977, 1983), and is believed to provide the foundation for social identification, perspective taking, and emotional connectedness (Metzloff & Gopnick, 1993; Meltzoff & Decety, 2003). Because imitation is a critical developmental milestone, it is of special interest to research in children on the autism spectrum. Charman et al. (2000) suggested that the study of imitation is necessary to inform our understanding of development in autism, specially the development of social communication, to determine the core skills that impact the long-term outcome of individuals on the autism spectrum. Imitation performance may predict gains in expressive or receptive language similar to tasks of joint attention (Mundy, Sigman, & Kasari, 1990) in autistic children and it appears that immediate vocal and gestural imitation in infants is positively correlated with expressive language development in the second year of life (Masur & Rodemaker, 1999). These results have led researchers to suggest that “joint attention and immediate imitation are important starter set skills that set the stage for social and communicative exchanges in which language can develop” (Toth et al., 2006, p.994). Following these findings, any delays or differences in the development of these “starter set skills” including gestural imitation, is an important focus in autism research.
In parallel, the underlying motoric disturbances in autism are a critical area of imitation research in children with developmental disorders, including ASD. Many children with ASD demonstrate difficulty in imitating manual gestures, even when they are taught signs (Page & Boucher, 1998). Seal and Bonvillian (1997) showed that measures of dyspraxia and fine motor coordination were positively correlated with the production and vocabulary size of manual signs in children with autism. However, the question remains as to the relationship between imitation and dyspraxia and the underlying cognitive mechanisms predicting gestural performance in autistic children and adults.