University of Edinburgh

Tactile Graphics

CHAPTER FIVE: Congenital Blindness

5.1 The usual pattern of development of tactile-kinaesthetic ability in young sighted children

Before considering some of the effects of congenital blindness on a child's development it is worth summarising briefly the normal pattern of tactile-kinaesthetic ability in young children as described by Williams, (1983).

Most of the ability in tactile perception develops by the age of five. There are no differences among five to eight year-old children in the ability to locate single point stimuli, but four year-olds are less accurate. There is unfortunately no information on developmental changes in the two point limen test. Only 50% of five year-olds are able to tell consistently when different fingers are touched simultaneously or sequentially. There is a steady improvement in this ability from four to eight but little improvement thereafter.

Three year-olds tend to explore an object by grabbing and patting it, but four year-olds begin to move their hands in meaningful exploration. Five year-olds are more systematic and by six the child uses the fingers to examine special features of an object and discover relationships. There is little apparent difference in ability to compare shapes between the ages of five to eight except that eight year olds are slightly faster. Ability to reproduce designs drawn on the back of the hand improves continually from four to eight year-olds.

Eight year-olds are much better than five to six year-olds in their ability to reproduce a given limb movement. When blindfolded, five to six year-olds are generally unable to keep a straight path throughout a 20ft distance, whereas eight year-olds are significantly more accurate.

Six year-old children with more advanced tactile kinaesthetic ability are superior to those with less well developed tactile kinaesthetic abilities in both gross and fine motor tasks. The differences in performance in the fine tasks are much greater between the two groups of children. By the age of eight, the differences are very slight. Although for younger children the level of tactile kinaesthetic functioning is not an important factor in the level of achievement in reading or conceptual development, it is much more important with older children (twelve to fourteen years). Williams (loc cit) believes that it is possible that poor tactile kinaesthetic development reflects weak cortical development which does not hinder simple motor tasks, but affects higher order cognitive operations much more severely.

In connection with research described in this book there are just three aspects of this developmental sequence which deserve immediate notice. Firstly, there is little apparent difference in ability to compare shapes between the average five year-old and the average eight year-old, except increased speed. This suggests that difficulties with descriptive tactiles presented to children at this age and beyond should not stem from a simple inability to discriminate and compare shapes. There may be difficulties related to the type of information presented.

The second point that may be noted is the improved ability to reproduce designs drawn on the back of the hand between the ages of four and eight. It seems reasonable to suppose that this runs parallel to a general improvement in drawing ability. With blind children, as has been mentioned in the previous chapter there are all sorts of hindrances to the development of the necessary skills, but the exploratory and drawing experiences which have been suggested in this book as being suitable for children in this age group should support and enhance this development in blind children.

Finally, the impact on higher order cognitive tasks of poor tactile kinaesthetic development is noted. Where blind pupils have been taught in a way which does not strengthen tactile kinaesthetic ability, often because some of the more practical and manipulative activities have seemed less important for blind children than the acquisition of information, it seems likely that cognitive development may also suffer, at least by the age of eight. It is unwise to generalise about this for all visually impaired children, but it appears that schools should put more stress on the systematic provision of opportunities for the development of tactual ability in such children and that this is likely to this is likely to aid the development of many higher order reasoning skills as well as manipulative skills.

5.2 The educational significance of congenital blindness

In the past a great deal has been written about the insurmountable difficulties of congenital blindness. Much of this writing has been unnecessarily pessimistic and some of the assertions made about the predicament of the congenitally blind are not in fact borne out by carefully investigated facts. (Birns, 1986; Cromer, 1973) Controlled experiments do not suggest that congenital blindness imposes any further limits on a blind person's general performance, given an adequate education, than late blindness, although it is admitted that the congenitally blind person works against a sensory shortfall which needs to be overcome by careful provision. It is also clear that there are individual differences in performance which override the late blind/congenitally blind division. Some of these may be the result of differences in earlier educational experiences. [Tobin, 1972, p 196).

It was a commonly held belief among some teachers and others, including the less fortunate congenitally blind people of an earlier generation, that 'the congenitally blind cannot understand tactile diagrams' but careful work and observations under conditions which are fair to the blind person show that this is far from the truth. The present writer has worked with some congenitally blind teenagers and younger children who are highly proficient in using diagrammatic forms of representation, not only as an aide memoire after careful schooling, but freely, imaginatively, and with genuine understanding.

Many congenitally blind people of an older generation went through a more didactic educational system in which rote learning was a notable feature. When they complain of difficulties with diagrams, their complaints need to be taken very seriously and met with sympathy and tact, but in the writer's experience rarely denote an insurmountable lack of ability. There is simply a lack of the type of preparatory experience which would lead to success. Happily, some of these people have found enjoyment and interest to a degree in illustrations for leisure pursuits which are now becoming available. (eg; Hinton, 1986 and 1989b).

What differences do need to be borne in mind therefore? There are some visual concepts such as colour, light and shade which can only be approached by the congenitally blind person through some mental effort unsupported by direct sensory experience. Despite this, such concepts as colour can be partially understood by association, and perhaps by some inexplicable imaginative construct understood by each congenitally blind individual only according to his or her personal definition. They become, therefore, concepts which are virtually impossible to describe and yet may be convenient to use in conversation.

Beyond such necessarily visual phenomena, most concepts can be learned by direct sensory experience if adequate opportunities are provided for direct encounter. However such encounters may not occur naturally in everyday life. It is thus vital that this type of opportunity is provided in the home or in formal education, particularly for the young congenitally blind child, and that objects which are not directly approachable because of their size, or for reasons of safety, are presented through some 'reality substitute' such as a model.

To cite two examples which are relevant to this discussion: A congenitally blind 14 year-old in the north of England was found to be unaware that the body shape of men and women was different and was therefore unable to begin to understand their differing reproductive function. At his age it was obviously a fairly urgent matter for his teachers to ensure that this lack of understanding was put right, and the writer was involved with the Health Education Authority in providing suitable teaching materials for this purpose. (Hinton, 1988c) One can understand why the boy mentioned had not acquired this knowledge, because to understand the secondary sexual characteristics and body shape differences of human beings he would need to feel live human bodies or good models. He was debarred from direct experience of this by normal etiquette and taboo, particularly where the opposite sex was concerned, and apparently models had never been provided for him. Small wonder that another such pupil once confessed to a sympathetic female teacher that in his early teens he deliberately contrived to fall against a female member of staff occasionally for no worse motive than wanting to obtain some of the morphological understanding which he knew he lacked.

Even where adequate models are provided by an understanding teacher in a sympathetic environment there is a degree of embarrassment which prevents a blind student from exploring parts of the model in public with the intensity which may be necessary for acquiring full understanding. This is why such students need a degree of privacy in this study which can only come from individual use of the teaching materials.

A completely different aspect of the problems which exist for congenitally blind students was the blind 9 year-old boy already mentioned who was found by the writer to have no knowledge of egg-cups, because when he ate a boiled egg his mother always fed him for fear of getting egg on his clothes. Hence, he had never handled an egg-cup, and probably had never handled an in-shell egg. So he did not realise that the egg would tend to roll on a flat table and so was normally held in a special vessel called an egg-cup. An illustration of an egg-cup thus meant little to him.

Such illustrations underline the need for wide-ranging handling experiences from earliest childhood, and for parents and teachers to be aware that such experiences need to be provided in a deliberate and cumulative manner.

Another characteristic of this condition is that the child does not have the strong visual role models to copy which are so potent in shaping the techniques and behaviour of fully sighted children. This can weaken the drive to attempt early activities such as standing upright and walking, for example, and at school it can also make such tasks as the controlling of a pen, scissors or other implements more difficult to learn.

The acquisition of an adequate pen-grip, important for a blind child learning to draw on German film, is a dear example of the kind of difficulty. For the fully sighted child it is possible to adjust the grip on the pen while looking at the teacher's pen-grip in a way that can give relatively quick results. Blind children can only feel the teacher's grip, aided by suitable instructions from the teacher, and then have to try to retain a mental model of this grip while attempting to recreate it. It can be done, but with a lot more difficulty and after more trial and error than most fully sighted children would need.

This problem also affects such activities as the drawing of straight lines free-hand as a preliminary to other drawing activities. In classroom work in connection with this project it has been found helpful to practise straight lines by constructing a 'fence' for which the teacher draws two horizontal lines about 5 cm apart. This gives the child a definite starting and finishing mark for a series of vertical lines, and a mildly interesting context in which to work. The close span of the two horizontal lines avoids the complications of forearm drag during the drawing of each line, and also reduces the chance of wandering which a longer line without parallel reference points would present. The distance can of course be increased as the child's skill develops.

Similar problems can occur with tasks such as drawing round a template. Here part of the problem, in the absence of visual feedback, is that the sensation of drawing the shape needs to be experienced as a psychophysical sequence. The actual kinaesthetics of the operation need to be experienced by the child's joints and muscles. This is of course even more important in the earlier stages of learning these skills.

In a teaching session the writer would normally get the child to draw round the template with the index finger 'to see what it feels like' before using the pen. To remain in close contact with the template requires some inward pressure, and the direction in which this needs to be applied will change as the pen progresses around the shape. The pupil can only avoid skidding away from the template by being aware of what is coming ahead of the pen. This knowledge comes partly from experience, and partly from the use of a finger of the free hand to feel ahead of the pen. (Some more dextrous pupils may use the lower fingers of the hand that holds the pen.)

Similar teaching techniques may also be necessary with blind children with some history of vision, depending on individual needs. Only by adequate interpretation of the kinaesthetic feedback using experience built up through plenty of practice can the blind child's drawing skill be consolidated. It is also important that teachers do not restrict the use of items like German Film for reasons of economy. A child with normal sight lays down the foundation of drawing technique in early childhood by 'scribbling' on countless scraps of paper. Thus fully sighted children in a nursery school go through a progression of making enjoyable hand and arm movements with paintbrush or crayon in hand (perhaps even with finger-paints), so that the movements are traced by lines or patches of colour on a sheet of paper. Then at a later stage these shapes have simple meanings attached to them by the child, who then begins to feel the need to refine and develop the link between the marks and what is depicted so that the meaning becomes clear to an audience. The opportunity to experiment is vital for the acquisition of control and fluency. It is not unusual for the blind child who is encouraged to draw in school (and not all such children are) to find that there is no opportunity for experimenting between formal lessons. The writer has found it necessary in teaching to provide the child with a few spare sheets of film for free practice in spare moments in class or even to take home to show parents or to work in privacy.

With regard to opportunities for direct contact with concrete objects, there are of course particular problems with objects which are inaccessible for safety reasons, or because their size is too vast or too minute to be detectable. Here the only thing that can be done is for some kind of reality substitute such as a model to be provided. With all models or tactile pictures it is important for the child to be aware of the relationships of scale. It is often helpful to make some anthropomorphic comparison to make clear the real size of the object depicted. If extremes of size make this impossible then a description of size or magnification reduction should be provided in some form appropriate to the subject matter and to the educational development of the pupil concerned.

It is also important to ensure that the child's experiences are not entirely formal and instrumental, but after also opportunities for imaginative and creative activity, Anderson (1984, p 209) suggests, apparently paraphrasing Olson (1981, p 375), that:

the curricula of nursery and primary schools should encourage congenitally blind children to investigate more creative or novel uses for common objects rather than simply to use the objects in a stereotyped, prescribed manner. If the creative tendencies of these children are to be enhanced, the children need to be challenged and encouraged to explore the properties and uses (real or potential) of objects, individually or in combination. Since blind children cannot imitate the exploratory and play behaviour of other children whom they cannot see, teachers and parents must model ways to explore and assist them to invent or discover new and different uses for objects.

From the writer's own experience of visually impaired children in school during continuing research it is clear that much is being accomplished along these lines in present day schools. There is also a heart-warming readiness on the part of sighted peers, or children with more residual vision, to involve a blind child in play activity. Nevertheless, it is still true that it is the tendency of the condition of congenital total blindness to cause passivity, and this needs to be overcome if the child is to lead a full life.

It is also true that in the competition for time and resources in the educational curriculum, creative, imaginative and play opportunities lend to be given low priority. The congenitally blind child loses more from this situation than does the child with full vision.

5.3 Older congenitally blind people and their  understanding of a scene

Much of the present writer's earliest work with tactile pictures as distinct from the more stylised graphic displays involved the depiction of objects or parts of objects in isolation. Such pictures can take the form of a simple plan, elevation or section and therefore be free of the complications of perspective which influence the depiction of a scene in pictures for fully sighted people. It cannot be too strongly emphasised that perspective is a purely visual phenomenon and is completely beyond the normal experience of a congenitally blind person, although the analogous fading of sound with increasing distance is a phenomenon of which blind people are aware, and this can be used as an illustration, The decreasing angle from the horizontal of a sound producer as it moves further away is also used by the writer in teaching about perspective to blind adults. The voice of a tall person close to the hearer appears to come from a high source, whereas as the speaker moves away the source seems to become lower and lower as well as more distant. (See Figure 4). The parallel is easy for an adult to understand.

auditory analogue of perspective

Figure 4: An auditory analogue sed in discussing perspective with congenitally blind adults

Perspective will be discussed in more detail in relation to visual picture perception in Chapters Six and Seven of this book. What has also been interesting in the writer's recent work with congenitally blind adults has been the discovery of more obvious features of pictures which are almost universal in the experience of the fully sighted and yet completely unknown to the congenitally blind person.

One example is the depiction of people facing in directions other than towards the artist. A very intelligent 40 year-old man who was congenitally blind was shown a tactile representation of a painting in which a woman was depicted from her back view. He became absorbingly interested in this picture because he said it had never occurred to him that an artist or photographer might show someone's back view. Yet the more he thought about it the more he realised that this viewpoint not only told him a great deal about the arrangement of the room, but also helped to explain the social relationships between the woman and the people with whom she was in conversation.

Another feature of visual pictures which is really one of the fundamental aspects of perspective is the way in which nearer objects are shown towards the bottom of the picture, and more distant objects towards the top. This is something which congenitally blind people have to be taught to interpret. It is outside their normal experience, unless they have useful residual vision. Bach-y-Rita (1972) and his colleagues (Guarnerio, 1974, p 103; White et al, 1970) had to deal with this problem in their TVSS training and the writer has had to teach users of tactile representations of paintings to understand the same phenomenon.

For the blind person objects are related in space by their distances and directions from each other in absolute three-dimensional terms. Where the distance overall is greater than the subject's arms can stretch the distances between features may be understood in terms of the distances travelled in getting from one to the other. Thus for the blind person there may be a passage of time between observations of one feature of the landscape and another, while for the fully sighted person the distance may be traversed by the eyes almost in an instant. It is the lack of this instant scanning which is perhaps the severest loss for blind students doing environmental fieldwork; individual features may be examined and assessed with ease, but to absorb their spatial relationships with any accuracy may be very difficult. Maps and diagrams help a great deal with this problem.

Both von Senden, and Gregory and Wallace (1963) were able to work with congenitally blind people whose sight had been restored after eye surgery. Gregory (1974, p 92) reports on such subjects responding to standard perception tests and visual illusions as well as to objects from their everyday environment. Gregory found a frequent referral back to tactile experience obtained while they were still blind, and often an inability to identify objects until they were verified by touch. (See also the closing pages of Hocken, 1984.) Subjects were able to describe features of an object which they could see without arriving at an identification of the whole object. Gregory also found that in the early drawings drawings of sight recovered people features were sometimes exaggerated according to their tactile importance, and the artists could have great difficulty in representing features which they had not had an opportunity to touch. (Gregory, 1974, p 102).

In some cases drawing skills improved along with other abilities in the newly found world of vision, (Ibid  p 105) but there were cases where reliance on tactile information could never be completely abandoned. (Ibid p 106).

Ron Hinton
First published 1996
ISBN: 0901580775