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Mary T. Morse
Originally appeared in RE:view, Spring 1999
In the last decade, children who are cortically visually impaired (CVI) have received increased attention and concern from the medical, educational, and rehabilitative communities. The Association for Education and Rehabilitation of the Blind and Visually Impaired has increased the number of sessions on CVI at its bi-annual conferences. The Journal of Visual Impairment & Blindness and RE:view have published many articles on varying facets of this often confusing condition. Several recent teleseminars were devoted to children with CVI. All of these efforts have increased our understanding of CVI and given many of us confidence to work with children who are cortically visually impaired. Because we should not become overly confident about our knowledge, I offer the following words of caution.
We need to be cautious not to oversimplify a complex condition. Despite its label, the term cortical visual impairment refers not to an eye condition but to a brain condition. About 80% of the brain, working as functional systems, is required to efficiently process and understand a visual message. We the workers, therefore, need knowledge of how the brain functions if we are to understand the implications of brain dysfunction (Dutton et al., 1996; Morse, 1990; Morse, 1992; Padula, 1996; Sacks, 1985).
Vision is also a psychological process; as a result, disruptions in visual function cannot be considered in isolation from other functions. Visual attention does not automatically mean cognitive understanding. We the workers should understand the implications of motor, cognitive, and communication problems when we plan habilitative visual services (Dutton et al., 1996; Morse, 1990; Morse, 1992; Nielsen, 1991; Padula, 1996: Padula & Shapiro, 1993; Sacks, 1985; van der Kolk, 1994).
A final factor to consider is that vision is an emotional process. All people with complete or partial sight have patterns of visual use and nonuse. People tend to use the visual system more when they feel confident about what they are expected to do, when they are listening to something that interests them, or when they want to relate to others. They tend not to use their vision when their senses are overwhelmed, when they are planning or thinking how to do something that is difficult (i.e., giving someone some bad news or when performing a difficult motor act); or when they are bored, tired, stressed, or feel submissive. We the workers should always consider what the child finds motivating and find ways to give the child a sense of self-efficacy in the activity (Morse, 1991).
We should be cautious not to assume that all children with CVI exhibit the same behaviors. The diagnosis means different things for different children; the effects depend on factors such as how extensive and severe were the insults to the brain, the developmental period during which the insult occurred, the child's previous experience, the presence or absence of additional disabilities, medications being taken, and the child's motivation. Some individuals with CVI have no observable visual responses: others have occasional responses to stimuli, whereas still others have a significant amount of usable vision. Some children have field restrictions and others do not. Even some of those who have significant peripheral field losses may be able to detect movement, perhaps through the secondary visual system. Over time and with or without intervention, many children show significant improvement in their general use of vision. That improvement may be the result of being more able neurologically to handle complex stimuli (Burke, 1991). Thus, we might see that as children understand their daily experiences more and as they anticipate routines, their functional visual behaviors also improve.
Even when visual behaviors improve to the point of appearing normal, many of the children may have significant difficulty with specific types of visual stimuli. For example, some individuals may be able to see a human face, know it is a face, but be unable to identify to whom the face belongs solely on the basis of the experience of visual information. That difficulty in visual identification may be similar to the experience of those of us who can discriminate cars from trucks but cannot identify the make or year of the car on the basis of our visual discrimination abilities. Faces are often confusing to individuals with CVI. The face changes with every expression and with every physical movement of different parts of the body. The face also presents a kaleidoscope of sensory information - visual, auditory, and olfactory. Moreover, a specific face may change depending on the hair style, on whether the individual alternates between wearing glasses or contact lenses or is using makeup or not. Identifying faces requires complex visual analysis. Other individuals with cortical visual impairment may be able to identify people and concrete objects as well as photographs of them but be unable to understand visual symbolic information in forms such as line drawings or print.
Some children with CVI may have difficulties with depth perception that go far beyond a situation such as mono-ocularity. Others may have significant difficulty in moving through even a very familiar environment. Dutton et al. (1996) described several children who can identify objects when they are moving very slowly but not when they are stationary or moving quickly. Padula and Shapiro (1993) discussed later-in-life trauma and see many patients who have associated strabismus, oculomotor dysfunction, convergence and accommodative abnormalities, diplopia, and balance and movement difficulties. Those patients described a world of distortions that did not match their previous visual memories. Those reports raise interesting questions about the individuals who attribute their CVI to congenital causes or early postnatal insult. The point here is that a major insult may have been localized to one or more specific areas but other parts of the cerebral cortex may or may not come into play and support the functions lost to the insult.
On casual observation, vision use in some children may appear normal. During the school years, however, some of these children may be described as being preoccupied, distractible, and inattentive when, in reality, some of their behaviors result from CVI. The observable school behaviors may be a result of fatigue from trying to interpret difficult visual stimuli. The visual components of a task frequently become even more difficult when combined with the demands of listening, maintaining position in space, and simultaneously performing complex motor actions (Dutton et al.,1996).
We should be cautious not to think that a single approach works for all children. As Sacks (1985) pointed out, a diagnosis of seizures is an insufficient label for prescribing a treatment regimen, and so too is a diagnosis of CVI.
Some children increase their visual awareness by such means as the use of lighted toys in a darkened room, the light box, distinctive geometric patterns, the use of bright colors, and sound toys (Baker-Nobles & Rutherford, 1995; Jan & Groenveld, 1993). Other children, however, tend to use their vision more efficiently and more frequently when they understand and feel comfortable with the tactile-kinesthetic-motor demands of the task. Farrenkopf, McGregor, Nes, and Koenig (1997) stated, "[T]ypical visual enrichment strategies do not work with children who have CVI because the visual sense is overwhelmed by the visual information" (p. 484). For example, a common lament among educators and therapists is that many children who are diagnosed with CVI tend to turn their head away as they reach for an object. One hypothesis is that the children are using their peripheral vision when they turn their heads away. That may be true for some. I have followed a significant number of children with CVI for over a decade (many on video tape) and believe that many of the children avert their gaze until they understand what their hands are doing. For these children, intervention might be referred to as vision through the back door, through the hands. That approach considers the complexities of the task's motor demands and the saliency of the tactual experiences so the brain becomes aware of what the hands are doing. It is the hand first; then the vision. When the hands explore real objects, they feed the abstract visual and cognitive systems (Affolter, 1991; Dutton et al., 1996: Hyvarinen, 1994; Morse, 1992; Nielsen, 1995: Padula & Shapiro, 1993; Sacks, 1985).
Many of these same children are extraordinarily attentive to environmental sounds. We need to be cautious that we do not assume that an interest in sounds automatically means an understanding of those sounds. Many, but not all, children with cortical visual impairment display varying degrees of difficulty with language. Indeed, processing auditory information may actually interfere not only with the use of vision but also with motor exploration. Much energy may go into trying to interpret the meaning of the sounds or the sounds themselves may provide a recreational diversion. According to studies by Farrenkopf et al. (1997) and Lane (1996), verbal prompts are not as effective as physical prompts. These children come to understand their visual world better when the language used around them does not interfere with attending to what the hands are doing. Interestingly, language is promoted more effectively when the words used conform to what the hands are experiencing (Affolter, 1991; Hodgdon, 1997; Koenig & Farenkopf, 1997; Lane, 1996; Morse, 1992).
We should be cautious not to view treatment as a linear and isolated training process. We need to recognize that simplification of the visual environment is not enough. Infants with no disabilities come to recognize those objects and people that have the most meaning to them (parents, bottle, favorite toy) through physical interaction in their everyday activities. For many children with CVI, reaching out and actively participating is a frightening experience. To them, the world may seem chaotic and unfriendly. Our interventions should examine the environments in which these children function, the activities in which they engage, the sensory-motor demands of tasks, time pressures, and interfering variables. We need to relate those factors to the individual child's ability to modulate his or her states of arousal, ability to determine which aspects of the task are the important ones to attend to, and memory. For many of the children we need to reduce the number of words we use while they are involved in highly demanding tasks. We should be more consistent in what we call objects and people. We also need to learn when not to talk. (Hynd & Willis, 1988; Morse, 1990; van der Kolk, 1994).
We need to be cautious about allowing our own egos and desire for student progress to interfere with our objective professional evaluation of the child's progress. Many of these students also have severe multiple disabilities that may prevent them from making obvious quantitative changes. Rather, many make qualitative changes. One of the most objective ways to measure change is to video tape a child 3 or 4 times during a school year. Determine ahead of time which behaviors are to be taped during which activities and develop an accompanying data sheet. Subsequently, have staff independently watch the tape and fill in their own data sheet from their professional perspective. The findings then constitute one measure of change. Subsequently, the composite data and the video tape may become part of the child's permanent record.
Those of us who work on behalf of children who have visual handicaps need to applaud our efforts to secure quality information to use on behalf of children with CVI. However, we should be forever diligent that we do not fool ourselves into thinking that there is a step-by-step single or simple method of enticing these children into their visual world and of assisting them in comprehending what they see.
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