Children with Cortical/Cerebral Visual Impairment (CVI) who use Augmentative and Alternative Communication (AAC) face unique challenges and receive intervention provided by professionals from multiple disciplines. However, research shows that there is a gap between what they need and what is being provided (Blackstone et al., 2021; Boster, et al., 2021). Professionals who serve these children often provide services in silos with limited guidelines and resources (Blackstone et al., 2021; Luo et al., 2022; McCarty & Light, 2023). Although limited, a retrospective longitudinal study conducted by our school show that with a comprehensive approach to AAC and CVI provided by an interprofessional collaborative team, these children’s vision can improve along with their communicative competence (Blackstone et al., 2024).
Over the years, through working with these children, as well as learning from families, professionals, and attendees of our webinars and conferences, we’ve recognized the need for a comprehensive approach. We have observed the negative consequences of professionals working in silos, where focusing solely on a child’s language needs, without considering their functional vision, seating, positioning, or sensory needs, could be detrimental. Similarly, decisions based solely on functional vision without addressing language needs were also problematic.
In 2023, a team led by Dr. Wilkinson from Penn State University proposed the AAC-CVI framework which has provided us with an excellent tool to demonstrate and share our comprehensive approach to AAC and CVI.
Besides sharing the original framework, we are sharing The Bridge School adapted version of it, as we added key areas that reflect our approach as well as some possible interventions that could be considered. We will continue to update the approach presented on this page with new findings from growing research on CVI and AAC.
We hope this approach can help you start your journey on supporting children with CVI who use AAC.
AAC-CVI Framework
*Blue text indicates adaptations to the original.
Domain: Skills brought by the Individual
| Characteristics | Diagnostic questions to consider | Assessment information needed | Possible considerations for intervention |
|---|---|---|---|
| Physical and emotional wellbeing | What is impacting the individual’s ability to engage/interact/use vision at time of assessment/intervention? | Medical status, medications, Attention levels & variations in alertness Preferences and interests Sensory needs | Incorporating sensory preferences and regulation Alternate input methods |
| Language comprehension and expression | Experience using symbols for language representation, where in the continuum is the person? Can communication needs be met by a visually accessible AAC tool, if not, can visually accessible communication tools be created as supplementary options? | AAC and Language Assessment Tools (E.g.: McArthur, C-BiLLT, Forms and Functions, Communication Matrix, AAC Profile, etc.) | Selection of Representation Mode(s) that considers language, cognitive and visual needs. Identify supports needed to transition to abstract representation modes. |
| Auditory function | What auditory/partner-assisted strategies are currently in use, and how might exploration of voice output from aided AAC or partners assist with learning of the AAC layout? | Auditory/hearing function, receptive language, use of scanning, use of exploration activities of voice output | Direct selection with support of auditory cues, PAAS, PAVAS Determine when auditory supports are needed (always, only for complex environments or fatigue?) |
| Level of functional vision | What functional vision does the individual have and how was it assessed? When was it assessed? What co-occurring ocular motor conditions exist? Based on results, is vision a possibility of primary input mode for AAC tools? Supplementary tools? Teaching materials? What idiosyncratic skills, if any, have the individuals developed to aid them in visual engagement (e.g., rocking, pushing away, resetting the screen, leaning towards AAC)? | CVI Range Score (based on interview with parents, observation and direct assessment), ophthalmologist report, parent input, teacher of the visually impaired input, 2D image assessment, learning media assessment, complexity of AAC layout assessment | Characteristics of visually accessible symbols (3D and/or 2D). Learning Media used for AAC tools (primary, supplementary, etc.). Consider information regarding tactile information Learning Media used for teaching materials. |
| Fine and gross motor, Visuomotor integration | How well does the individual use their vision to guide their reach? | GMFCS Seating and Positioning Visual field deficits, fine/gross motor abilities, observation of sequential vs. simultaneous visually guided reach | Accommodations for seating and positioning Access method: direct selection vs. eye-gaze, use of keyguards or touch-guides, consistent location of high-frequency vocabulary. |
Domain: Responsibilities of the Communication Partner
| Partner’s response to individual CVI characteristics | Diagnostic questions to consider | Assessment information needed | Possible considerations |
|---|---|---|---|
| Manage linguistic complexity | |||
| Manage environmental complexity | What is the impact of multisensory environmental factors on visual function (e.g. overhead lights, decorated walls, ceiling fans, teacher clothing, sound/noise level, and movement of people/things in the visual field? | Engineer the environment to promote visual engagement, participation, independence: Manage distractions created by IAs or teachers moving, talking, and assisting. Alternate layouts or access methods for busy environments that are part of the child’s life (e.g. recess time, grocery shopping, etc.) “Make communication possible in all environments” | |
| Consider placement in visual field | How does the location in which the stimulus appears in the visual field influence visual engagement? What are the student’s preferences? | ……stimuli are presented in different visual fields, including left/right, upper/lower quadrants, and periphery | Present stimuli on easier fields when other goals are present, time is limited, etc. Present stimuli on harder fields when time is available and other supports are in place (use of color, light, etc.) Decide location of communication partner depending on their role (e.g. a partner within an interaction on an easier side, if only supporting, locate where they would be least distracting). |
| Consider distance from individual | What is the optimal distance of the stimulus from the individual to maximize visual engagement (inclusive of any coexisting ocular needs such as nearsightedness). | … the distance of presentation of the individual is varied | Present stimulus at optimal distance. Use camera’s on tablet, video recording for stimulus presented at a distance. |
| Use movement to present stimuli | What is the effect of adding movement cues during stimulus presentation on visual engagement? | … the stimulus tracks from one side to the other of the side (left to right, right to left), or the stimulus grows/recedes in size upon presentation. … the stimulus is enhanced with shiny materials (processed in the brain as movement). | Use movement (actual movement or shiny materials) to attract and engage visual attention) |
| Provide wait time to assist with visual latency | How long should the partner quietly wait after presenting a stimulus to support the individual engagement? | … presenting stimuli of different complexity, contrast, lighting, etc. given the different design considerations in the rest of the table. | |
| Provide visual breaks to accommodate visual fatigue | Sensory balanced schedule | ||
| Consider individual’s preferences – do not presume competence-potential benefit |
Domain: Features of the AAC system
| Characteristics | Diagnostic questions to consider | Assessment information needed | Possible considerations |
|---|---|---|---|
| Design feature in response to individual CVI Characteristic | Aided AAC consideration (all ages/language level/ CVI Range phases) | Measure latency and duration of visual engagement when | |
| Representation Modalities | What is the student’s primary learning modality? Secondary? | All assessments previously mentioned. | Based on language needs, language comprehension, auditory processing and CVI characteristics, decide on representation modalities of AAC tools. (Be mindful that visual access can increase over time) Auditory only Tactile only Visual + auditory and/or tactile Visual |
| For tools using visual modalities: | |||
| Internal symbol complexity | What level of complexity within the symbol can the individual engage with / recognize? | ..simple vs complex stimuli are presented. Consider colors and patterns within the symbol and varying representations (object, photograph, realistic illustrations, abstract illustrations, etc..) Assess symbol complexity (2D Image Assessment) | Consider that selecting text as a representation mode involves the consideration of a whole set of aspects. |
| Number of symbols presented on the array | How is visual engagement/accuracy affected for large arrays vs small ones (one or two symbols)? | ..symbols are presented one by one, in pairs, larger arrays. Assess complexity of array | Alternate layouts or access methods for complex environments, visual fatigue or when needed |
| Familiarity of symbols | What is the impact of familiar vs. novel symbols on visual engagement? | …stimuli of familiar vs. unfamiliar partners, settings, objects are presented. | Provide longer wait time with novel symbols, pages. Symbol pre-teaching |
| Symbol background and foreground | How do characteristics of the symbol impact visual engagement? | …symbols with complex background, background removed, black background, symbols that are overlapping, | Remove symbol background or use simpler background when appropriate. Alternate presentations of symbols that have overlapping components. |
| Color | What impact do color cues have for promoting visual processing? | … | |
Adapted by The Bridge School from: Wilkinson, K. et al., 2023. “An Evidence-Based Approach to Augmentative and Alternative Communication Design for Individuals with Cortical Visual Impairment. AJSLP
