An Evidence-Based Approach to Augmentative and Alternative Communication Design for Individuals with Cortical Visual Impairment
Authors:
Krista M. Wilkinson, Lynn R. Elko, Emma Elko, Tara V. McCarty, Dawn J. Sowers, Sarah Blackstone, Christine Roman-Lantzy
Main Research Question: AAC Design for CVI
How can augmentative and alternative communication (AAC) systems be designed to meet the specific visual and communicative needs of individuals with cortical visual impairment (CVI)?
Key Findings/Results: Tailor AAC for Unique CVI Needs
The study emphasizes the importance of tailoring AAC systems to the unique needs of individuals with CVI, a brain-based visual impairment that affects how the brain processes visual information. Effective AAC designs for CVI reduce visual complexity, optimize symbol arrangements, and employ adapted navigation methods. Reducing the complexity of displays with fewer symbols and familiar images can mitigate challenges associated with CVI. Motion-based navigation, such as a swipe gesture, and strategic auditory feedback can further enhance usability. Emma, a 20-year-old with CVI, exemplified these findings, showcasing how personalized AAC adaptations improved her ability to communicate effectively.
Methodology Used:
The authors employed a mixed-methods approach that combined literature reviews, clinical insights, and a case study. Emma’s journey served as the focal case study, illustrating how iterative modifications to an AAC system could address specific visual and motor challenges. Systematic observation of her interactions, assessments of her visual processing, and ongoing adaptations informed the development of a practical and evidence-based framework for AAC design for CVI.
Significance of the Study:
CVI is the leading cause of pediatric visual impairment in developed countries, yet traditional AAC systems often fail to address its unique challenges. Dense visual displays and reliance on typical visual processing overwhelm many users with CVI. This study provides an urgently needed framework for creating accessible and effective AAC systems that enhance communication, promote independence, and foster inclusion. By integrating scientific research, clinical expertise, and lived experiences, the study bridges gaps in both AAC design and service delivery.
Main Conclusions: Individualized AAC Design for CVI
This study demonstrates the critical importance of designing AAC systems that address the unique needs of individuals with CVI. By prioritizing customization of a system to an individual's unique needs, these systems enable users to reduce barriers and experience meaningful access to aided communication. Features such as adapted navigation and reduced visual complexity enhance usability. Emma’s case exemplifies the potential of these systems to transform lives, offering a blueprint for how interdisciplinary collaboration can create impactful solutions.
The authors advocate for a paradigm shift in AAC design, urging practitioners and developers to center their work on the needs of users and to foster ongoing collaboration among stakeholders. This approach ensures that AAC systems not only meet immediate communication needs but also empower individuals with CVI to achieve greater independence and social inclusion.
Detailed Breakdown and Case Study Integration:
Tailoring AAC Systems for CVI
The study identifies customization as a key principle for designing visually accessible AAC systems for individuals with CVI. Unlike conventional AAC systems, which often feature dense symbol arrays, effective designs for CVI users prioritize reduced visual complexity by limiting the number of symbols per display. For example, Emma’s system initially included just two symbols per page. While her functional vision improved, her current system continues to display only five symbols (words) per page with links to multiple pages to access additional vocabulary. This approach, utilizing a non-complex array of five symbols per page interlinked to pages with additional vocabulary, allows her continuous engagement with a non-frustrational AAC system, regardless of the environment.
Motion-based navigation, in Emma’s case, utilizing a swipe gesture to navigate to those interlinked pages, also proved impactful. Removing traditional navigation buttons simplified Emma’s display, conserving space for critical content symbols. Initially, motion cues were integral in helping Emma locate and select symbols, particularly in environments with high sensory complexity.
The intentional use of color and familiar images further enhanced usability. The use of a dark background with brightly colored images drew Emma’s attention, while familiar symbols and personalized content facilitated comprehension. These features allowed her to transition from body-based communication to the effective use of her AAC device in daily life.
Case Study of Emma
Emma’s journey highlights the transformative potential of customized AAC adaptations. Diagnosed with CVI and motor impairments, she initially struggled to use conventional AAC systems, which did not accommodate her visual needs. Through systematic adaptations—including simplifying displays, teaching motor gestures like swiping, and integrating auditory feedback—her system was aligned with her abilities. These changes empowered her to navigate her device independently and communicate effectively, even in complex sensory environments.
Emma’s progress underscores the importance of an iterative approach. Initially, her AAC system displayed just two symbols per page to reduce visual clutter. Over time, as her visual processing improved, the system expanded to include more symbols and pages, supporting a broader vocabulary. Her success demonstrates how adaptive designs, informed by ongoing assessment, can dramatically improve communication outcomes.
Challenges Addressed by the Study
Traditional AAC systems often fail to account for the unique challenges posed by CVI, such as difficulty processing complex visual arrays and reduced visual fields. Many families report inadequate guidance and resources for addressing their children’s communication needs. The study addresses these gaps by presenting evidence-based design principles tailored to the needs of individuals with CVI. Key recommendations include reducing visual demands, simplifying or customizing navigation, utilizing familiar images, and the intentional use of color.
Future Directions
The findings have significant implications for AAC design and implementation. Clinicians, educators, and developers are encouraged to utilize individualized assessments to inform adaptations and customize design and navigation to ensure systems are responsive to users’ evolving needs. The study emphasizes collaboration among researchers, practitioners, and families, fostering inclusive approaches that empower individuals with CVI. With the prevalence of CVI rising, the framework provides a roadmap for creating accessible, effective communication tools that promote independence and social participation.
Wilkinson KM, Elko LR, Elko E, McCarty TV, Sowers DJ, Blackstone S, Roman-Lantzy C. An Evidence-Based Approach to Augmentative and Alternative Communication Design for Individuals With Cortical Visual Impairment. Am J Speech Lang Pathol. 2023 Sep 11;32(5):1939-1960. doi: 10.1044/2023_AJSLP-22-00397. Epub 2023 Aug 18. PMID: 37594735. https://pubs.asha.org/doi/10.1044/2023_AJSLP-22-00397