Cortical Visual Impairment affects the brain’s ability to process what the eyes are seeing. One of the central characteristics of CVI is visual complexity. Children with CVI have a difficult time looking at objects with a complex surface, (complexity of pattern), or at a scene with many objects grouped together (complexity of array)i. This is because busy patterns with many colors make it difficult to discern the overall shape of an object, and therefore recognize it. When objects are grouped close together, children with CVI may not be able to recognize each object as separate from the others. We can think of both of these characteristics when we look at a herd of zebras:
If I ask you to count the animals in this photo, looking at just the outline of each animal is a little confusing, because they tend to blend together. Not only is it hard to tell where the zebras’ heads and legs are, (complexity of pattern) but it is hard to tell one zebra from another (complexity of array). Your brain does some amazing visual categorization in milliseconds to decide how to define each shape as a zebra. You might begin to look for the salient visual features of “short dark mane,” or “long swishy tail” or “groups of four legs” and count those to support your guess about how many zebras there are. One of our strategies when helping children with CVI is to point out these salient visual features explicitly, so they can start to make sense of an image like this one.
Literacy is one of the most important expectations we have for children, but it poses one of the biggest challenges to children with CVI. Just like the zebra photo, complexity of pattern makes recognizing individual letters difficult, while complexity of array makes it hard to distinguish the edges and shape of one word for anotherii. This type of visual processing is so automatic in people with unaffected vision, it is hard to imagine what it might feel like to a child with CVI. Matt Teitjen, a Teacher of the Visually Impaired who studies complexity, compares the experience of visual complexity with trying to fluently read a technical passage without punctuation, capitalization, or spaces.iii Try reading the text below from a journal article about visual processing:iv
Did that feel overwhelming? To simulate this challenge the way Matt presents it, imagine reading this passage in the middle of a noisy restaurant! Without the familiar arrangement of spaces, punctuation and capitalization, our brains have a much more difficult time organizing the information and making sense of what we read. For children with CVI, complexity of pattern and array make learning to read feel as difficult as the example passage.
There are many approaches to reading instruction. The phonics-based approach, among the most widely adopted in mainstream school systems, includes exposure to letter shapes and letter sounds, pairing the shape to the sound, learning how letter sounds blend, recognizing simple words, applying letter blends to larger words, and reading those words fluently within phrases, sentences, and paragraphs.
For children with CVI, this approach is not always effective. While children in late Phase II and early Phase III on the CVI Range (with scores of 3-7 and 7-10, respectively) may be able to view isolated letters and discriminate, recognize and identify them, visual complexity increases dramatically once individual letters are paired together to form longer words. How can we expose children to printed materials if they are unable to cope with the complexity those materials create?
Dr. Christine Roman proposes an alternate approach to literacy that flips the learning process around by beginning at the word level. By teaching specific words adapted to the child’s CVI Range score and that are grouped around a familiar and motivating context, children can learn to recognize whole word shapes, rather than trying to process the shapes and sounds of groups of letters. The shape of a whole word is taught through its salient visual features; by describing its length, the characteristics of its letters, and by surrounding the word with the child’s preferred color so that the shape stands out as a single object.v
By teaching contextually related words in pairs, we can use comparative language to point out the similarities and differences between words that are visually distinct from each other.vi These words are chosen because they represent concepts that are deeply understood by the student in the real world. They may surround memories of a sporting event, or time with the family watching the game on TV.
We can even isolate the color outline so that the word can be matched, sorted, and recognized by its shape. As the child works towards this ability, they are strengthening their understanding of letter shapes and sounds with whole word shapes:
A benefit of this approach is that words can be chosen which are relevant and motivating to the child regardless of their length or composition. Some children may identify a core group of words that support access to communication on a device, or that allow the child to identifying key words at home or school that increase independence. Other children may move on from this approach and develop fluent smooth reading.
How do we ensure a child has the visual skills needed to support a symbol-based literacy approach that includes the use of letters and words? The child needs to have stable and consistent ventral stream function, which is typically present when a child scores around a 4 on the CVI Range. In addition, the child should be able to recognize a wide range of familiar target objects with ease. This demonstrates the ability to use both salient visual features and comparative thought to sort, categorize, and reflect on what they see. Children should be able to identify these objects, and view them as both real objects (3-D) and images of objects (2-D). Once the child has a very strong concept of the target object, the real object or image can be replaced with a symbol, such as a whole word, or abstract color image (like those used in many AAC systems). In some cases, using highlighted bubble-word text as a communication symbol may be easier for a child with CVI than the cartoon color and black-and-white symbols found on communication devices, which do not reflect enough salient visual features for a child to compare and interpret.vii In determining an appropriate approach to literacy, Dr. Roman shares these sentiments:
I now know that some children with CVI will achieve the prerequisites for reading and ultimately become competent readers, while others will follow a different path. But I cannot forsee ahead of time which individuals with CVI will read, so I believe that all children must be provided a path to literacy. […] There is no eye report, no neurological history, no MRI, or degree of cerebral palsy that seems to be correlated with being able to learn to read. I do know that all individuals with CVI are more capable than they can demonstrate in Phase I CVI, when there is little access to the visual world. So I encourage my colleagues to take the risk of believing that your students with CVI are capable of literacy no matter what form it ultimately takes.viii
Using Word Bubbling helps us rethink the problem of complexity when teaching print literacy for children with CVI, and for some children, these strategies have been incredibly successful. Print-based literacy like the model described above may not work for every child with CVI, but if the prerequisite skills are there, we cannot know what the child is capable of unless we give them a chance to show us.
i Roman, 2018 p. 40-44
ii Roman. 2019 p. 38
iii Tietjen, 2019 lecture,(Concept borrowed with permission)
iv Hoyt, 2003
v Images generate using The Roman Word Bubbling tool, a web-based app designed to complement this literacy model.
vi Roman, 2019 p. 29
vii Tietjen, 2019
viii Roman, 2019 p. 37
Hoyt, C. S. (2003). Visual function in the brain-damaged child. Eye, 17(3), 369–384. doi: 10.1038/sj.eye.6700364
Roman-Lantzy, C. (2018). Cortical visual impairment: an approach to assessment and intervention(2nd ed.). New York: AFB Press.
Roman-Lantzy, C. (2019). Cortical visual impairment: advanced principles. Louisville, KY: APH Press, American Printing House for the Blind.
Tietjen, M. (2019, April). What's the Complexity Framework - Spring 2019. Perkins eLearning. Watertown, MA.
Zebras - "Zebra herd" by Nagarjun is licensed under CC BY 2.0