Infusing T2L Literacy Supports into AAC for Individuals with Developmental Disabilities with Different Needs and Skills

Abstract

Literacy skills are essential for full participation in education, employment, and independent living (Light & McNaughton, 2013). For people who benefit from AAC, functional literacy skills are also critical for generative, independent communication as literacy offers a modality for accessing receptive and expressive language. Unfortunately, these same individuals are often left out of literacy instruction and enter adulthood without functional literacy skills (Foley & Wolter, 2010).

Functional literacy skills require the integration of multiple skills (e.g., phoneme segmentation, letter-sound correspondence; Adams 1990). Direct instruction in foundational literacy skills, including letter-sound correspondence and decoding, has been shown to be effective for people who use AAC across a wide range of diagnoses when adaptations are made to facilitate participation (Yorke et al., 2021).

However, many individuals who are preliterate use picture-based AAC systems and these systems often do not provide supports for learning literacy skills. Technology supports built into AAC systems offer a promising addition to traditional literacy instruction to facilitate the acquisition of literacy skills by AAC users. Specifically, the development of Transition to Literacy (T2L) features that can be infused within AAC displays may be highly effective for targeting early literacy skills including sight word reading (e.g., Caron et al., 2020; Holyfield et al., 2020), letter sound correspondence (Pope et al., under review), and single word decoding (e.g., Brittlebank & Light, 2025; Holyfield et al., 2024) The design of the T2L feature was guided by what is known about basic visual-cognitive processing and early literacy learning. Specifically, the T2L features use motion with text enlargement, luminance, and speech output to support visual attention to the written word and phonological recoding of the text. Additionally, these features can support comprehension by connecting the written text with a known symbol. The Transition to Literacy (T2L) features can be integrated into AAC applications to support formative literacy skills to supplement systematic, direct literacy instruction. Research shows that these T2L features support increased sight word, letter-sound correspondence, and decoding skills for individuals with developmental disabilities.

In this session, we aim to: (1) demonstrate and describe the evidence-based transition to literacy (T2L) features within the context of literacy instruction for individuals who benefit from AAC; and (2) provide an overview of different applications of the T2L features for people who benefit from AAC with a wide range of needs and skills.

To date, research has demonstrated the effectiveness of the T2L features across a range of children, adolescents, and adults with developmental disabilities (e.g., Down syndrome, autism spectrum disorder, cerebral palsy) who use and benefit from a range of AAC systems, including both direct access and alternative access techniques.

These T2L features have successfully been embedded within visual scene display systems (Mandak et al., 2020; Holyfield et al., 2020); video visual scene displays (Holyfield et al., 2019); and grid-based systems (Caron et al., 2018; Caron et al., 2020) to support sight word learning. More recently, T2L features have also successfully been implemented to support letter sound correspondence, decoding, and encoding.

Further, we will examine the context in which these skills were targeted. Thus far, the T2L features have been implemented with individuals in a range of appropriate activities including shared book reading (Pope et al., under review), seek and find (Brittlebank & Light, 2025), conversational tasks (Holyfield et al., 2024), and funny animal videos (Brittlebank et al., in preparation).

With each of the studies we highlight, we will discuss the individuals , the literacy skills targeted, and the context and activities used in the interventions. We aim to provide examples of ways we have used the T2L feature to increase exposure to literacy skills for individuals with a wide range of needs and skills who benefit from AAC. In doing so, we will highlight a number of studies that have been conducted by this research team all using the T2L features to target literacy skills.

In this presentation, we will share information on the aspects of the T2L feature and how they specifically support literacy learning. Additionally, we will outline the wide range of intervention tasks and activities we have used to naturally incorporate the T2L feature. This presentation will highlight a wide range of studies that have been conducted investigating the T2L features and discuss how individuals (not just speech-language pathologists) can use these features to support literacy learning for individuals who benefit from AAC.