Identifying and Validating Prelinguistic Communicative Forms and Functions in Children with Developmental Disability
While children with developmental disabilities often fail to develop speech, many will nonetheless engage in a range of prelinguistic behaviours. Prelinguistic behaviours include actions such as eye gaze or eye pointing, pointing with a finger, facial expressions (e.g., smile, frown), and body movements (e.g., waving an arm, leg extension). The purpose of this research project was to evaluate procedures for (a) identifying prelinguistic forms in the repertoires of children with developmental disability, and (b) validating the communicative function, if any, of these existing prelinguistic behaviours. This was achieved through a three-phase study involving a total of 10 children with developmental disabilities and their parents. For Phase 1, the author interviewed each child’s parent(s) and teacher using a structured protocol; The Inventory of Potential Communicative Acts (IPCA; Sigafoos, Woodyatt, Keen et al., 2000). The IPCA has been used in numerous previous studies to identify prelinguistic behaviours that are interpreted as forms of communication. In Phase 2, the author used informant report to identify and replicate six situations: three in which each participant was reported to communicate a specific function and three in which he/she reportedly did not communicate. The author then compared the children’s responses during the clinical trials to the behaviours he/she was reported to use for the targeted function. In Phase 3, the parent replicated the structured trials used in Phase 2 to determine whether participant performance varied relative to communicative partner. Findings from this study provide evidence to support the validity of the IPCA as an interview protocol for identifying potential communicative acts in children with developmental disability and severe communication impairment. The comparisons made between the reported communicative behaviours used for each function revealed both similarities and differences across children. The results also provide evidence that children with severe communication impairment and developmental disability are using similar behaviours to communicate specific functions across different environments and with different communicative partners.