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Which Predictors Play an Important Role in Successful Deaf-Blind Education?

by Dr. Jan van Dijk on Nov 30, 1986
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Full text of a presentation in which Dr. van Dijk, discusses important predictors for deaf-blind children's functioning levels in particular learning areas.

Reprint permission, courtesy of Dr. Jan van Dijk, 2001



"Nothing is more practical than a good theory" (Paul Moor).

Some practical people in education do not like "theory" because they find theory on child development and education not very valuable for their daily work. This is true when the theory presented is too abstract or too general; however a good theory makes it understandable how different variables are related to each other. Such a framework of coherent structures might serve the worker in the field as a sound foundation for his work. Unfortunately we lack such a comprehensive theory in the field of deaf-blind education. This is partially due because of the heterogenious population. The teacher of a low functioning rubella child who reads Helen Kellers's Story of My Life will find very few valuable principles in that book to apply in the education of his student. This teacher may raise questions such as: "How can I reduce stereotyped behaviour in my student, and if I manage to do so, will this improve his exploratory behaviour?". Before raising this question the teacher might have wondered why this student exhibits these behaviour patterns. Is it because the child is mentallv retarded? Visually impaired? Or, is the child e.g. rocking because of a severe hearing impairment? In other words, the teacher has developed hypotheses how all these variables may be connected. Even more he might have thought that one variable causes another one e.g., lack of vision "causes" eye pushing. What the teacher can do is test these hypotheses with sound scientific analyses. If he collects enough data on visually impaired children who poke their eyes, he is able to test the assumption that lack of vision causes eye pushing. The statistical technique he applies might show that there is a relationship between the two variables. If he uses the statistical technique of step-wise regression he might find that one or more independent variable(s) predict(s) one or more dependent variable(s), as a result a regression line can be formulated that could indicate the more visually impaired the child is, the more intense his eye-poking is. As a second step, he might add hearing-loss as an independent variable in the regression equation. The outcome can be that visual impairment and hearing-loss contribute to the explanation of the behaviour. As a third step the variable of intelligence might be added. The outcome might be that this variable contributes very little to the explained variance.

One goal of research is to find the causal structures. This goal is not only for the sake of knowledge but for the development of better educational strategies that are not based on experience alone but also on the results of scientific analyses. Unfortunately not many studies undertaken in the field of deaf-blindness meet the strict statistical criteria of group research. This often is quite understandable because finding large samples of deaf-blind subjects is difficult, and furthermore the subjects are difficult to test. Fortunately other techniques exist that can be used, such as single-subject designs (Barlow and Hersen, 1984) which tell us more about the individual child. We believe that group and single-subject approaches are valuable.

In this presentation, we will put forward some findings which we believe are important predictors for deaf-blind children's functioning levels in particular learning areas. We base our knowledge on our past research involving rubella deaf and deaf-blind children, and on the research literature of other etiological categories of deaf-blindness.

1. Most of the individuals who are hearing and visually impaired are victims of congenital rubella. In different stages of their embryological development, the rubella virus insulted the normal growth process. We hypothesized that the later in pregnancy the infection took place, the less neurologically damaged the child would be. The status of the neurological system reflects itself in the child's learning potential. In order to measure this a learning test was applied, the Hiskey Nebaraska Test of Learning Aptitude. This test consists of items which are related with the scholastic learning of deaf children. The memory items especially give an indication whether the child is capable of learning a communication system (Van Dijk 1982; Van Uden 1974; Broesterhuizen 1984). We entered eight sub-tests into the regression equation with the time-of-infection as the independent variable. It was rather surprising for us to find that the time at which the children had been infected in utero was such a strong predictor for performance on six out of the eight Hiskey subtests. Since the regression coefficients were positieve, this indicated a significant relationship between later infection times and good test results.

Research has shown that all rubella children with cataracts were infected before the 3rd month in utero. It can be argued that with deaf-blind rubella children the central nervous system involvement is rather prominent. Du Bose (1981) suggested that the low level of performance of deaf-blind rubella children is caused by sensory-organ damage which interferes with the incoming information from the environment of the brain. Follow-up studies of patients with congenital rubella discount this assumption (Gumpel 1971; Desmond 1970; Chess 1971).

It has been found that between 45-70% of rubella children with bi-lateral cataracts were mentally retarded. A recent study on a carefully selected sample of deaf-blind children, including large proportion of rubella victims, mentioned similar percentages (Wolf, Delk and Schein, 1982).

The neurological symptomatology of deaf-blind rubella children covers a wide range of problem areas such as motor deficits, hyperactivity, stereotyped movements and poor adaptive behaviour. In anatomic studies of the brains of rubella children vascular abnormalities of some type were found in half of the cases (Rorke, 1967). Adjacent to the areas of vascular damage in the brain, atrophy of cells were found.

Attention should be given to the hypo-cellularity, a condition associated with congenital infection, that prevents normal cell division and growth. Rorke (1967) suggested that the synaptic connections in the brain are less branched out in these victims in comparison with non rubella victims in the same age-qroup. This might influence important learning processes such as conditioning and giving attention to novel stimuli (orientative reflex). Hypoplasia of the corpus colosum was shown in rubella patients. This indicated that the integration between both hemispheres was hampered. The exact effect of the neurological dysorganisation on learning is difficult if not impossible to determine. Through careful observations on how learning processes take place, areas of (dys)functioning can sometimes be detected (see Broesterhuizen, these proceedings). It may become apparent that a particular type of stimuli is processed more adequately by the brain than another. Our study suggested for instance, that visual stimuli attract rubella children's attention almost immediately. Educationally speaking since the attention process is so strongly related to effective learning,it is important to investigate this area further.

One of the main reasons why we think we are so successful with some of our deaf-blind students is that we have explored the attention and memory processes and used our results in building a careful curriculum. In the development of communication, memory functioning is crucial. In accordance with modern theory of memory, we "add" rather carefully the other modalities of the visual mode. An "associate" chain can be formulated in this way: spontaneous (visual) interest - object - drawing - sign - fingerspell initial letter of the word - printed word - spoken word. An important finding is that the ability of the child to build up such a chain is more dependent from his memory function than his "IQ".

2. In the literature dealing with deaf-blind children, also with blind, mentally retarded and autistic children, one finds an enumeration of stereotyped and adventitious behaviors such as hand-flapping, finger-licking, moving the hand or objects in front of the eyes, or rocking. Sometimes these acts increase when the environment becomes more complex or when the child is left alone. All educational researchers agree that stereotyped behaviour patterns interfere with learning. We have described the variety of these motor-acts in detail and we have attempted to analyze these behaviour patterns (see Van Dijk 1982 for further references).

We hypothesized that the duration of pregnancy, time of infection and or birthweight contributed to these motor-acts. Our conclusion was that these prenatal variables only play a modest role in the explanation of stereotyped behaviour patterns in our sample. Only infection time and birthweight were significant predictors for stereotyped behaviours that were centered around light. We were somewhat surprised to find that the degree of hearing loss was not an important predictor in the development of stereotyped behaviour.

When we entered the variable bi-lateral cataract in the regression equation, it became very apparent that visual-loss was an important predictor of certain types of stereotyped behaviour, especially those in which light play a role. This is in accordance with our theorv that early visual deprivation has a great influence on the development of some abnormal behaviour patterns.

The conclusion from our study is that the visually impaired child who is very difficult to nuture because of low birthweight, is very likely to develop a wide variety of stereotyped motor behaviours. How to reduce these stereotyped patterns is a continuously reoccurring issue in the field of abnormal behaviour.

Different approaches have been attempted. In the framework of our deprivation theory it seems logical to apply techniques such as infant massage to reduce stereotypes. In some instances, this technique is effective. With other children, the self stimulation increases.

One of our important findings is that anxiety has a negative effect on stereotypes (see Van den Tillaart). The opposite is true as well: The feeling of security diminishes the stereotypes. The development of the sense of security in the child is dependent on the responsiveness of the caretaker. In this recent work with severely impaired children, including visually impaired rubella children, Murphy and his co-workers found that behavioural techniques in which external reinforcements were used had no effect in decreasing stereotyped behaviour; neither did the introduction of new toys. He was highly successful however by introducing toys which were immediately reinforcing to the child, e.g. lifting a part of a toy caused a light to go on. This immediate reinforcement made the children more active, and they generalized this behaviour to other situation (Murphy 1983). The educational outcome is more hopeful in those children who through careful educational management can be "changed" from passive subjects to more active exploring individuals. If careful observation (multiple baseline) shows that the child's behaviour does not change despite all the educational strategies attempted, very little hope exists that the child's adaptive behaviour will grow.

3. In connection with the aforementioned propositions we would like to draw attention to the dyspractic child. At the Institute for the Deaf, Sint-Michielsgestel, The Netherlands, a number of research projects have been carried out to show the relationship between sensory motor integration and learning (Van Uden 1974; Broesterhuizen, van Dijk and IJsseldijk 1981).

When a child is neurologically damaged, it is rather obvious that the damage will be manifested in his motor coordination. We pursued this theory further in connection with rubella children and found that motor development (age of walking) and fine-finger-motor control were predictors for the proficiency of activities such as manipulating small objects (e.g. paper folding) and drawing. Also it was found that our group of visually and hearing impaired children was very backward in their arm coordination as well. Since many forms of expressive communication require bodycontrol drawing, signing, speech), it can be predicted that the clumsy child will have extreme difficulties in acquiring a made of communication in which motor coordination plays a dominant role. This is a highly important issue, because selecting a communication system beyond the child's motor competency leads to frustration, anxiety for failing, an increase of stereotypes, and, last but not least, to passivity. This might be the reason why autistic children encourage only signing and not the use of other forms of communication, e.g. picto-grams, communication boards, and the printed word. In some cases the printed word can be produced by the child himself by using the electronic communicator.

A final word on fingerspelling:

In our children who suffer from the syndrome of dyspraxia, fingerspelling (one-handed) is used, so as we do with some of our deaf-blind children. Is this not in disagreement with the aforementioned information because fingerspellinq is motoric in nature? Broesterhuizen (1986) found this not to be a contradiction. By using factor analysis his results showed that in a group of severely dyspractic children, the ability to fingerspell loaded on the language factor and not on the motor competence factor. This is in agreement with our observation that severely dyspractic deaf-blind children have less problems in learning how to fingerspell than how to sign.

The findings printed in this paper show again that curricula for deaf-blind children will only lead to success if built on research and careful observations of the child's behaviour and learning!

Dr. J.P.M. van Dijk


Barlow, D.H. and Hersen, M. Single Case experimental designs. New York: Pergamon Press, 1984.

Broesterhuizen, M., Van Dijk, J., IJsseldijk, F. Psychological and educational assessment and evaluation. In A.M. Mulholland (ed.). Oral Education'Today and Tomorrow. Washington: The Alexander Graham Bell Association for the Deaf, 1981.

Broesterhuizen, M. Dove kinderen met spraak- en taalproblemen. Taal als visuele vaardigheid. In Tien jaar Eikenheuvel. J. van Dijk (ed.), Sint Michielsqestel (The Netherlands): Instituut voor Doven, 1984.

Broesterhuizen, M. Intelligentie, taalvaardigheid en qeheugen bij meervoudiq gehandicapte dove kinderen. Sint-Michielsgestel (The Netherlands): Instituut voor Doven, (in press).

Chess, S., Korn, S., & Fernandez, P. Psychiatric disorders of children with congenital rubella. New York: Bruner, Mazel, Butterworths, 1971.

Desmond, M.M., Wilson, G., Vermand, W.H., Melnick, J.L., & Rawls, W.E. The early growth and development of infants withcongenital rubella. Journal of Advances in Teratology, 1970, 4 39-63.

DuBose, R. Assessment of severely impaired young children: Problems and recommendations. Topics in Early Childhood Special Education, 1981, 1 (2), p. 9-21.

Gumpel, S.M. Clinical and social status of patients with congenital rubella. Archives of Diseases in Childhood, 1971, 47, 330-337.

Murphy, G. Calleas, M. and Carr, J. Increasing simple Toy Play in Profoundly mentally Handicapped Children I. TrainiLngto Play. Journal of Autism and Developmental Disorders, 1981, 14, 375-189.

Rorke, L.B. & Spiro, A.J. Cerebral lesions in congenital rubella syndrome. The Journal of Pediatrics, 1967, 70, 243-255.

Van Dijk, J. Rubella Handicapped Children. The effects of bilateral cataract and/or hearing impairment on behaviour and learning. Lisse: Swets and Zeitlinger, 1982.

Van Uden, A. Dove kinderen leren spreken. Rotterdam, University Press, 1974.

Wolf, E.G., Delk, M.T. and Schein, J.D. Needs assessment of services to deaf-blind individuals. Silver Spring (MD): Rehabilittion and Educ. Exp. Inc. 1110 Fidler Lane, 1982.

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