AAC Symbols & AI for Individuals with Cerebral or Cortical Visual Impairment (CVI)

Cerebral or Cortical Visual Impairment (CVI) in children is usually the result of developmental damage to the brain rather than any damage to the actual eyes, although both types of visual impairment need to be assessed early on, but are very different, as is stressed in the RNIB Cerebral visual impairment and PMLD article and by CVI Now in Understanding the CVI Visual Behaviors

Image produced from a helpful YouTube Video "ISAAC Cortical Visual Impairment The Everyday Impact on People who use AAC"

There are also a series of blogs written in 2018 by Deirdre McLaughlin CF-SLP, Denee Kroeger OTR/L, and Kayley McDonald OTD from Communication Matrix on "Clinical Practice Application For Children With CVI" and these offer some very practical advice although, as with all individual difficulties, the range of skills varies hugely. However, visual attention and perception can be improved when appropriate support is in place and environments are not like a kaleidoscope of objects and colours. Movement can be helpful for visual attention - shiny and shimmering, but this will not necessarily lead to language or literacy generation but can be used early on.

Our aim is to learn more about specific designs for AAC symbols as it is rare to find open licence symbol sets offering alternatives to black and white options. Three spinning tops thanks to Pixabay and Sclera symbols, where the multicoloured version is like a kaleidoscope, but objects seen as a whole with a suitable colour against a black background may be more easily perceived, especially when presented individually rather than in an array in a learning situation.

The more components a symbol has the more likely it is to cause overload in visual processing, as with a complex environment. A complex and cluttered symbol causing the kaleidoscope effect makes it much harder to understand or learn a concept. A single straight line is a component and so is a circle that represents a face. Adding lines and dots and circles and then more circles increases the complexity until the whole can no longer be processed. Some of the most recent research work on this subject was shared by multinational attendees at the 2024 Perkins CVI Conference in USA. The site has many links to advice and guidance including the components that make up the environment and task complexity framework.

These high contrast symbol examples are available with a licence from Tobii Dynavox Picture Communication Symbols® (PCS)

Colour also needs to be very carefully considered as individuals may have specific colours they like or completely fail to attend to unless prompted when in amongst other colours. Linda Burkhart and Gayle Porter presented slides at ISAAC 2012 that have some very helpful examples in their PDF handout on "Combining Visual and Auditory Scanning for Children with CVI and Complex Communication Needs." and AAC & CVI: Can We Chat? is a blog by Carole Zangari that also highlights the issues of colours and complexity when symbols are used on communication boards.

Paths to Literacy in USA have a blog about Moving from Three Dimensional to Two Dimensional symbols and Dr. Roman-Lantzy’s book "Cortical Visual Impairment: Advanced Principles" includes a CVI 2D Image Assessment.

So how do we keep complexity out of the picture if we are using AI generated symbols? Here is a trial using the Mulberry Symbol set as a style guide and a few tweeks to make a black background for prompts that said 'yellow man runnning', 'a yellow child sitting on a chair' and 'a red ball on yellow boxes' - verbs 'run', 'sit' and preposition 'on'. Definitely not perfect and human intervention is still needed because only the last symbol of the three will probably be sufficiently clear.