Research has demonstrated that parents' use of synchronous language, which is language that follows their children's focus of attention, is related to language development in children with autism spectrum disorder (ASD; Haebig, McDuffie, & Ellis Weismer, 2013a; Haebig, McDuffie, & Ellis Weismer, 2013b; Siller & Sigman, 2002; Siller & Sigman, 2008). Furthermore, experiments demonstrate that professionals can teach parents to increase their use of synchronous language when interacting with their children (Aldred et al., 2004, 2012; Green et al., 2010; Siller, Hutman, & Sigman, 2013). This investigation is part of the longitudinal Early Social Interaction (ESI) project and compared pre- and post-measures of parent synchronous language across two different intervention conditions that varied on intensity. A total of 82 children between the ages of 17 and 20 months of age and their parents were randomly assigned to either parent-implemented intervention (PII), which was offered in three individual sessions per week for 6 months, or information, education, and support (IES), which was offered in one group session per week. Findings revealed that parents in both intervention conditions significantly increased their use of synchronous language at similar rates after six months of intervention. Additionally, there was a significant time by treatment interaction for parent use of undemanding language indicating that the PII group increased their use of undemanding language over the course of intervention and the IES group did not. Additionally, significant relationships were observed between six-month levels of parent synchronous language and child outcomes measured on the Communication and Symbolic Behavior Scales (CSBS; Wetherby & Prizant, 2002). Finally, parent use of synchronous language was significantly related to parent behaviors displayed in a home observation three months after collection of the clinic measure. Results of this study suggest that parents increased their use of synchronous language after participation in either intervention condition, both of which targeted parent synchrony. However, undemanding language may require more hours of training for parents to make changes during six-months of intervention. Furthermore, the findings of this study suggest that parent synchrony was not an active ingredient in mediating child change.
