Strategies in Construction and Interpretation of Graphic-Symbol Sequences by Individuals who use AAC Systems

Abstract

Given the frequent use of graphic symbols in augmentative and alternative communication (AAC) systems, some individuals who use AAC may have greater familiarity with constructing graphic-symbol sequences than do speaking individuals without disabilities. Whether this increased familiarity has an impact on the interpretation of such sequences or on the relationship between construction and interpretation is fundamental to our understanding of the mechanisms underlying communication using graphic symbols. In this study, individuals who use graphic-symbol AAC systems were asked to construct and interpret graphic-symbol sequences representing the same target content (simple and complex propositions). The majority of participants used stable response patterns on both tasks; a minority were inconsistent on both tasks. Asymmetrical patterns (stable on one task but not the other) were rare, suggesting that neither channel (construction or interpretation) preceded the other, in contrast to earlier findings with participants without disabilities (i.e., novice users of graphic symbols). Furthermore, there were differences between stable and less stable responders on measures of syntactic comprehension and cognitive level but not on chronological age, receptive vocabulary, or AAC system characteristics and length of use.

Keywords:

• Augmentative and alternative communication
• Graphic-symbol sequences
• Production
• Comprehension
• Syntax

Notes

1. In order to avoid confusion, throughout this article, the terms production and comprehension will be used to refer to the expressive and receptive domains of the oral modality, whereas construction and interpretation will be used as the corresponding terms for the graphic-symbol modality.

2. In all analyses, the use of the symbol WEAR was considered optional, since it was the only symbol that did not need to be contrasted with another in order to make the message clear. In previous work, we found that considering WEAR as optional vs. mandatory did not impact the results of the analyses.

Acknowledgements

The authors wish to thank all the participants who so generously gave their time to take part in this study, and the research assistants who collected the data. This study was made possible through funding from the Social Sciences and Humanities Research Council of Canada (grant # 410-2002-1031) to the first three authors. Additional financial and material support was granted by the Centre de recherche du CHU Ste-Justine and the Canada Foundation for Innovation. The writing of this article was also supported in part by the National Science Foundation Science of Learning Center Program, under cooperative agreement number SBE-0541953. Any opinions, findings, and conclusions or recommendations expressed are those of the authors and do not necessarily reflect the views of the National Science Foundation. The second author is now affiliated with the École des sciences de la réadaptation, Université d'Ottawa.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.