Cortical Vision Impairment: Using the Sense of Sight as a Secondary Sensory Modality.
by Lilli Nielsen, Refsnaesskolen, Kalundborg, Denmark.
(This article first appeared in Danish in Refsnaes-Nyt, no 41, 1994.)
Anne is eight years old. She has vision problems because of cortical visual impairment. Until her sixth birthday she reacted visually only to sunshine. Now she also reacts visually while lying underneath an umbrella from which is hanging objects that she can suck, grasp by means of her mouth, and push using her nose and mouth. She is unwilling to use her hands for grasping. Anne also reacts visually while exposed to the Little Room.
It would be too easy to say that she reacts visually in familiar environments. She does not react visually while being fed or cared for or in any other environment that she has experienced daily during her life, and so much more often than in the environment provided by the umbrella and the Little Room.
What is it then, that makes her react visually underneath
the umbrella or inside the Little Room? Is it the contrast of colours
of the objects hanging under the umbrella, or from the ceiling and the
walls of the Little Room? Are the objects in question especially visually
stimulating? Or is it the shape of the objects that encourages Anne to
look at them?
No, visually it does not seem to matter what shape, colour, contrast or contours. What is important for Anne is that she can grasp the objects using her mouth, that she can mouthe them, taste them, and also make them swing to and fro by pushing them.
Recently Anne has started to move her hands towards her mouth. When this activity has become familiar maybe she will begin to look at the fingers she has been sucking.
Jacob was seven years old when he started to react to light. Sometimes he also seemed to fixate on an object, but whether fixating or not, he did not reach for an object, nor display any prolonged interest in looking at the object.
The toys he was given were chosen for their auditory and tactile qualities rather than for their visual qualities. Gradually Jacob became more and more interested in experimenting with making sounds with the objects and in touching those objects which had strong tactile qualities. One day when he was nine years old, he sat once again in the Little Room, pushing objects and so producing sounds. Suddenly he visually tracked an object that was swinging to and fro because he had just pushed it. When the object stopped moving he reached towards it and grasped it. During the following months he increasingly reached for something he had seen. This did not mean that he used his sight in situations where use of sight would have been to his advantage, eg, if he had been given something new with which he could be active, or if he intended to perform an action that one of the adults usually did for him it was important to him to start the new activity without being watched. In such situations he would turn towards the adult and listen intently, but without looking at the adult. When he thought that the adult was not paying attention to him, he carefully started on the new task without looking at it, but rather using a kinaesthetic-auditory or a kinaesthetic-tactile approach.
After having performed this same activity 20 to 30 times he sometimes looked at the materials, but only for 1-2 seconds, after which he continued the activity using a combination of kinaesthetic-tactile or kinaesthetic-auditory sensory experiences. By eleven years of age he was able to feed himself if some food had been placed on the fork. He did so without looking at anything at all. By 12 years of age he looked for the fork before he took it.
How can these observations be interpreted?
Morse (1990) and Groenveld (1990) think that children with CVI are sometimes unable to see. This apparent lack of ability to see has also been discussed by this author (Nielsen, 1990). However, are the conclusions stated in these articles the only explanation of the cause of temporal blindness? Could other causes for or explanations of the child's temporal inablity to use his sight be found by observing what the child is doing while not using his sight?
Observations of Anne and Jacob and several other children with CVI seem to show that they are busy using other sensory modalities while they are not using their sight. This happens especially when the toys are still rather unfamiliar to the children or when the sounds from the surrounding world are new, or when the child has a particular need to know what is going on around him, or when the child is searching for what is within reach.
So it seems that the more familiar an object an environment or an event has become by the use of those sensory modalities that are primary for this child, the easier it is or the more motivated the child is to start looking at whatever occupies him.
This is probably because during the first years of life while he was still unable to see or had light perception only, the child learnt to experience the surrounding world by means of his well functioning auditory, tactile, olfactory and kinaesthetic sensory modalities. The child also seems to consider it most beneficial and meaningful to combine information from these sensory modalities whenever he becomes interested in an object or event. Therefore he keeps utilizing those sensory combinations that from the beginning have been and still are primary for him. When new objects are presented to the child he also seems to be unable to concentrate on using more than two sensory modalities simultaneously. For some children these can be the kinaesthetic and the tactile, while for others the kinaesthetic and the olfactory sensory modalities. Only when the combination of the information from two sensory modalities has become familiar is the child ready to add to it information from a third sensory modality (Nielsen, 1989, 1992)
So the child needs to explore, for example, the auditory and tactile qualities of an object before he can benefit from looking at it.
Some children with CVI may later become able to include the sense of sight when exploring, experimenting and experiencing an exciting object or event for the first time - others will maybe never achieve this ability. Some may always have to experience new objects by means of their primary sensory modalities before they can include visual experience.
Consequently, instead of being temporarily blind, the child is so concentrated on using other sensory modalities that he simply does not use his ability to see. While functioning in this way the child will probably benefit from having the opportunity to enhance his knowledge of tactile and auditory qualities as much as possible, that is, to practice without being encouraged to look. The child will commence to use his sight when he is ready or when it is beneficial for him to do so.
In promoting this process it is essential to identify which sensory modality is primary to the child and then to provide the child with toys and materials that can promote his use of that sensory modality. At the same time though, it is important to identify the stage in the learning process that the child has achieved, so that the environments arranged for the child's activities match both his developmental level of the ability to see and his level of learning to comprehend what he is seeing (Nielsen, 1993).
Whether the sense of sight will continue to be the child's secondary sensory modality probably depends on the child's general ability to comprehend or on the child's intellectual potential. Also the child's physical ability is of importance. Manipulating and looking at an object simultaneously requires hand rotation, as well as the ability to fixate and to move focus from one detail to another. The older the child is when he starts to see something the more inclined he seems to be to rely on auditory and tactile more than on visual qualities.
How to facilitate the child's opportunity to include visual information in the combination of sensory experiences based on primary sensory modalities depends on the child's interest, motivation and physical skills.
It was with hesitation that I commenced this article with the reports on Anne and Jacob, because every child with CVI is different from any other child. So the two reports should never be considered a formula. It takes a very long time - maybe several years - before the sense of sight becomes the primary sense in the way that we who have normal sight consider it to be. Maybe the auditory and/or the tactile sensory modality will continue to be the child's primary sensory modality. However, the better and the more differentiated the child is in his ability to utilise the auditory and tactile sensory modalities and the more objects and surroundings that have become familiar to him, the easier it will probably be for him to utilise his ability to see so that he can learn what he sees. Maybe later, just looking at an object will be sufficient for him to be able to imagine the auditory and tactile qualities of this object, how heavy it is, and what it looks like behind and underneath.
Groenveld, M., Jan, J.E. & Leader, P. (1990): Observations of the
Habilitation of Children with Cortical Visual Impairment. Journal of Visual
Impairment & Blindness. January.
Morse, M.T. (1990): Cortical Visual Impairment in Young Children with
Multiple Disabilitites. Journal of Visual Impairment & Blindness.
Nielsen, L. (1993): Cortikal synsnedsaettelse. Refsnaes-Nyt, nr. 38. Refsnaesskolen,
Nielsen, L. (1994): Mere om cortikal synsnedsaettelse. Refsnaes-Nyt nr.
39. Refsnaesskolen, Kalundborg.
Nielsen, L. (1989): Spatial Relations in Congenitally Blind Infants. Refsnaesskolen,
Nielsen, L. (1992): Learning Object Concept and Permanence in Blind Infants.
Paper read at the ICEVH's Conference in Bangkok. Published in Information
Exchange no. 40, March, 1994. RNIB, London.
This article was printed in the journal "Information Exchange" Spring 1998.