- Selected Topics
- Accessing the General Curriculum
- Auditory Training
- Calendar Systems
- Concept Development
- Daily Living Skills
- Environmental Considerations
- Harmonious Interactions
- Lilli Nielsen and Active Learning
- Orientation & Mobility
- Play & Recreation
- Social Interactions
- Tactile Strategies
- Universal Design for Learning
- van Dijk Approach
The Sint-Michielsgestel Approach to Diagnosis and Education of Multisensory Impaired Persons
Current philosophies and new approaches for persons who are sensory impaired and multiply handicapped
Reprint permission, courtesy of Dr. Jan van Dijk, 2001
Dr. Jan van Dijk
Head of Inter-disciplinary Diagnostic Centre
Instituut voor Doven, Sint Michielsgestel, Netherlands
Tuesday August 8, 1989
In this contribution I would like to present the theory of deaf-blind education as developed by myself in collaboration with my colleagues at the deaf-blind department of the Institute for the Deaf at Sint Michielsgestel, the Netherlands. Our diagnostic and educational approach has attracted world wide attention and many professional workers in this field have developed programs based on our ideas. Some of them have based their work on a part of our theoretical principles, e.g. the ideas of "co-active movement as the basis for language development" [Writer, 1987, Hammer, 1989] or have introduced the idea of "predictability of events" by using day/week calendars or memory boxes [Rowland & Schweigert, 1988].
It has been urged that a comprehensive theory should be presented by us based on empirical facts, including measurements of the effect of the program [Writer 1987]. I have been challenged to carry out this request. In the near future a study will be published, which hopefully demonstrates the strength of our diagnostic and educational models [Van Dijk: Persons handicapped by rubella. Victors and Victimes. A Follow-up study. In preparation]. In this paper I will present some findings of this follow-up study and will compare the data with those found by other researchers in this area. I am aware that empirical data without a logic cohesive theory is not of much help for the teacher or parent whose task it is to educate multi-sensory impaired children. I would like to attempt both: present here our basic philosophy, supported by relevant data. The latter I will do in a rather descriptive way but I will refer to the literature where the exact data can be found.
The target population
Before describing the theory, the question arises for what type of handicapped persons our theory is meant. It has emerged from our work with deaf-blind children, who were mainly victims of maternal rubella. These persons had mostly severe to profound hearing losses and were visually impaired because of bi-lateral cataract. The effect of congenital sensory deprivation manifested itself in the behaviour of these individuals. I have found that the strong tendency of these persons to light-gaze and move their hands in front of their eyes is strongly related with the visual loss and that in the behaviour of stereotyped jumping the degree of hearing impairment plays a role [Van Dijk 1982]. Another important result of my early research was that the learning ability of these individuals at the ages of six years was rather strongly predicted by the time of infection during pregnancy, and that motor ability was significantly predicted by the independent variable birth-weight. These measurements can be considered as
parameters for neurological involvement. [Early] prenatal infection has often a strong impact on the development of the individual. This in combination with the sensory impairments make these persons rather unique. They should not be considered as primarily mentally retarded individuals and that the sensory impairments "only" aggravated their condition.
From an educational standpoint this should be rejected. There is evidence that the education of these persons and the efforts to improve their behaviours require a very special intensive approach, which is different from educational methods applied in the education of the "only mentally-retarded persons".
It should be noted here that recent investigations came up with data which indicate that within this population a sub-classification can be made. Dunlap was able to classify a fairly large sample of 251 deafblind persons into three distinct groups. On the basis of four variables - gross motor, language, leisure and socialization, 30% could be classified as "high functioning" and 42$ belonged to the middle group, while the remaining part belonged to the group of "low functioning individuals" [Dunlap 1985]. It is of great importance to note that in the latter group were significant more individuals with severe visual problems than in the "high functioning" group, where the individuals were significantly more severe hearing impaired, but had better vision. In our own rather small sample [N = 18] we found a rather clear distinction between a group of really low functioning individuals and a group who had developed some language and whose adaptive behaviour was fairly appropriate. Since we had assessed all these persons 12 years earlier, inspection of the "early" data revealed that with two exceptions this distinction was already present at that time.
The lower functioning group can be characterized as mentally retarded individuals with strong tendencies of withdrawal and reluctance to engage into conversation. As indicated by Curtis, Donlon and Tweedie "avoidance" is the low-functioning deaf-blind individual's preferred strategy in coping with his or her environment [Curtis et al. 1975]. A possible explanation of this behaviour can be found within the framework of the social learning theory [Bandura 1977]. This theory states that in all learning it is necessary that the subject identifies stimuli that serve as positive reinforcers and that [s]he retains this reinforcing proporties over many administration [Sisson 1988]. To put it more simply, persons who are unable to recall that a certain person provides a particular pleasurable reinforcement, will not develop a special relationship with this person. By the same token this person will not remember [daily living] situations in which [s]he has been successfully engaged before. This learning has to start all over again and does not build upon previous success. It is understandable that these subjects' behaviours are rather resistant to change and their cognitive [language] development is limited. It is obvious that this type of extreme memory disorder in this persons, is often associated with [severe] retardation and that it appears quite typical in this subgroup. We should drawn here attention to the neuropsychological model presented by Lamendella and recently advocated by Prior as an important hypothesis-testing model for autism [Lamendella 1977, Prior 1987]. Lamendella associates both the development of social relationships and the ability of mammals to modify behaviour as a result of experiences and instrumental learning with the functioning of the limbic system, in particular with the memory function of the amygdala and hippocampus. Such a model can be very enlightening in the development of a theory of treatment for these persons. It explains that multiple impairment can occur as a consequence of insult or deficits in a single primary area [Prior 1987, p. 14]. It explains too why development must be considered as a bottom-upwards process, this means that low zones have to be intact for adequate functioning of higher zones. These principles are the foundations of our educational approach to multi-sensory impaired persons who are severely delayed in their development and are reflected in the theory of mother-infant banding, the so-called attachment theory.1. The role of theory of attachment in the treatment of multi sensory impaired children.
The psychoanalyst John Bowlby has laid the basis for the now widely accepted theory of early social and emotional bonding. He concluded that "contact comfort" was important and that a young infant should receive appropriate care and stimulation from a limited number of people [Bowlby 1982]. In order to receive this contact-comfort there is a desire in the infant to seek proximity, this tendency is met by the mother during early development. If this secure steady base is provided, the infant is motivated to investigate changes in his environment, providing that the stimuli are moderately intense and regular. Intense and irregular stimuli result in withdrawal [Salzen 1979]. This approach-withdrawal behaviour can already be observed in neonates: gently contact will elicit extensor responses e.g. opening of the hand when being touched, while strong stimuli will elicit flexor responses [the child "closes-up"] or even moves away. This is the beginning of internal experiences and primitive consciousness, as can be derived from the infant's crying. At 2 weeks of age a differentiation already takes place between "global crying" and a general "discomfort cry". Initially this behaviour does not have intentional character; whether this occurs depends entirely on the ability of people in the environment to make correct inferences about the state of the infant. This is the lowest base of nonverbal communication in which the limbic system plays an important role.
One may assume that in the very early stages of a first differentiation is made between stimuli which cause comfort or discomfort in the child. Accordingly his reactions can be called "appetitive" or "aversive". The limbic system is also responsible for facial expressions and vocalizations. As a result of environmental response to the instinctual expression the infant becomes involved in a network of social relationships and at one month of age foundations are laid for the attachment of the infant with his mother. This is enhanced by the special attention which the child gives to the human face, to which the child responds earlier preferentially than to the human voice [Salzen 1979]. The role of vision and hearing is very prominent in the attachment process. As already indicated by Harlow and his colleagues touch contact has at least equal importance as both distance senses on the bonding-process.
Experiments have showed that when primates were exposed to extensive visual and auditory experience but deprived from early physical contact they appeared to be grossly impaired in social interaction [Harlow 1964]. Contact stimuli are without any doubt a source for attachment orientation. The role of memory in this process, is, however often overlooked. An instrumental learning process takes place through the reactions of the environment on the child's expressions of his internal state [comfort or discomfort] or his response to an environmental stimulus. Situations are becoming more familiar through experience. As a consequence of this the child's orientative reactions diminish. The child habituates to the stimulus. He learns too how people will respond to his behaviour. At an early stage there is also learning about the emotions of other people. For example, when the child is addressed by a pleasant tone it will sooth him, however, an angry face will make him cry. Again it seems that the basis of understanding other people's emotions are laid at a very early age and that both operant conditioning and the memory functions of the hippocampus play an important role in this process.
It is hypothesized that the mother's ability to pick up infant's cues and her appropriate reaction has effect on the child. It gives him a feeling of security and develops the notion in the child that in moments of distress the mother will be available to "contact". There are mothers of children, however, who can be characterized as persons who are "clumsy" in dealing with children. Sometimes these mothers respond immediately to a minor cue, in other circumstances the child has to insist for a long time before he is picked-up. Being inconsistent in her responsitivity towards the child seems to account for the strong proximity - and contact seeking and maintaining of these infants, who often cry frequently.
Taking these findings regarding attachment into consideration and relating these to the sample of [multi] handicapped rubella persons in our follow-up study, the following general picture emerges: Most of the rubella babies are born at term after a pregnancy often characterized by stress on the part of the mothers, since many of them were aware of the possibility of delivering a handicapped child. After birth most of the newborns exhibited problems in their management, due to [very] low birth-weight and failure to thrive. It can be assumed that in many of these newborns the virus was still present, so the mothers were dealing with sick babies [Van Dijk 1982, Coll, Dumoulin & Souriau, 1983]. The development of eye-contact, for which the feeding situation is so important, was virtually impossible in the babies with cataracts. As already stated visual behaviour plays a crucial role in social interaction.
Therefore it may be contended that in babies with visual problems the highly sophisticated signal relating system between infant and mother was absent from the start of life. In other words the development of mother-infant synchrony failed to develop. During the time these babies were born removal of cataracts was only common practice in the second part of the first year of life, with even some extractions occurring much later. The consequence of this was that not only was the early stage face-to-face interaction hampered, but also the subsequent stage of mutual looking to the same object.
Since this "mutual regulation system" between mother and infant was absent and hearing could not play its "compensatory" role as in blind "only" infants, the deaf-blind baby's seeking for comfort and security had to come from direct contact. Unless this process of the touching of a deaf-blind baby is very well guided, the mother's direct contact with her child will only arouse confusion and chaos in the child. Henceforth the baby will not learn to associate the comfort or security touch with a particular person. This is why many deaf-blind infants do not recognize their mothers as special persons who provide security, until much later in life, if this happens at all. As the seeking of security is a biological imprinted behaviour pattern in virtually all primates, in the care of absolute confusion they will cling to any figure or object which may provide comfort. When such a figure is absent, one may note self-clutching, jumping to be picked up, self-orality [biting on lips or fingers] and motor stereotypes. This picture is universal in these children and the analogy striking with e.g. monkeys reared in total isolation without adequate sources of contact stimulation [Salzen 1979].
In our follow-up study we have observed that this proximity seeking [hanging onto persons] mingled with the angry behaviour of resistance, continues to be present in some of these individuals for the rest of their lives. As explained earlier, if a secure base is lacking in an infant's life, this may affect his exploratory behaviour. We found a part of our deaf-blind subsample to be extremely passive. The theory developed here explains to a certain extent the social withdrawal, the stereotypes, the aggressiveness and the passivity of a part of the subsample of the deaf-blind group.
The intriguing question arises, however, as to what extent the lack of basic security influences intellectual development. In other words, if these [now] low-functioning persons had been approached in the way we will describe later, would their development have been so aberrant as these individuals manifest themselves now.
Experiments with a carefully organized preschool program with deafblind children indicated that their level of functioning could be increased significantly [cf. Appell 1977].
Considering all the stressful events happening in a family with a handicapped and difficult to manage child, it is quite understandable that in some instances a "fully secure base" is lacking, which has its effect on social competence. There is no sense in denying this - on the contrary this issue should be pursued further:a. by the further development of instruments which can be used to assess early mother [handicapped] child interaction patterns; b. by the development of instruments which measure the effect of early intervention programs; c. by the development of a theory on which a basis for intervention programs may be developed which may lead to the prevention of the problems described in the previous paragraphs.
In the following section the general outline of such a theory will be presented.2. Appetite versus aversion
In her impressive paper on the effects of a combined vision and hearing loss on a child's development, Fox describes the experience of such a child as "imprecise, unpredictable and unfiltered". In other words there is only chaos in the child's life, he does not know to which stimuli to orientate [Fox 1985]. This is a clear description of a
[multi] sensory impaired child, who lives in an unstructured environment, where persons touch the child indiscriminatively, present him/her with objects which may raise the level of anxiety or which lead to an increase of stereotyped [motor] acts.
We would like to draw attention here again to the fundamental aspect of [human] communication: the approach - withdrawal system, which is based on gentle - strong / irregular stimuli respectively [Salzen, 1979]. We have presented research data which explained that when the distance receptors, especially vision, are not functioning, so-called "precurrent action" for contact stimulation is impossible. Instead that this contact leads to orientation movements such as exploring the person who provides the contact, the child will either withdrawn or accept the contact in a passive non-exploratory way. Neither reactions can be considered as "communicative".
We are not aware of any assessment procedure, which tries to determine which kinds of contact stimuli bring about "approach" and which ones "withdrawal".
In our approaches to these children we try to determine by carefully touching the child at different places on his body, what types of contact stimuli lead to an "approach" of the child. In doing so one may notice that the child may pay more attention to one type of stimuli than to other kinds. At this level [of limbic activity] there is already an abundance of sign behaviour that communicates information about the affective state of the child [Lamendella 1977]. One may notice an "appetite" reaction when blowing gently into the child's mouth [oral-facial stimuli], or when rocking the child gently or when spraying him with lukewarm water. The purpose of this approach is to "map-out" areas which may elicit orientative reactions. Responding to these in a consequent manner, may lead to signal behaviour [Sokolov 1960, Meshcheryakov 1979, see also Nielsen, 1987]. This procedure should not be confused with merely the "massage" approach, where the child is overwhelmed with stimuli. It is our purpose to create an environment which enhances the development of orientative behaviour and of communication. One will notice, however, that after presenting the child with the same type of stimulus [s]he will "get used" to it. The "novelty" has disappeared, the child has "habituated" to the stimulus. This indicates "memory" function and means that in order to again elicit orientative behaviour, one has to present a slightly different stimulus. The child may show surprise, because his expectations are "mismatched". There are clear indications, when taking the plasticity of the nervous system into consideration, that an intensive intervention program based on eliciting orientative [anticipatorial] behaviour, may enhance intellectual performance [Kimmel, 1981].
When the caretaker notices that the child has become aware of the "mismatch" by change in level of attention, and the caretaker responds appropriately to it, the child will start to feel that he is able to "control" the events happening in his environment [internal locus of control].
Intervention programs, for this population which should be designed after careful assessment, have to be centered around activities and objects which elicit "appetite" behaviour. This can only be established when the activities are conducted according to regular daily time intervals, carried out by the same person, preferably the mother. Since "appropriate responsiveness" is the key-concept in this approach, this person should be supervised carefully. Immediately feedback "on-the job" seems to be the most effective method for this [Seys & Duker 1986].3. Development of attachment
In the literature on attachment it is generally agreed that through "sensitive appropriate reactions" of the mother/caregiver the child gradually learns what he may expect from his attachment figure, and [s]he learns to predict his behaviour. This leads to a feeling of security.
In the population discussed here of [dual] sensory deprived children, the signals the child emits, may be hard to recognize and receive. In order to facilitate this we have introduced the so-called "co-active movements and responsiveness". [Van Dijk 1965, Writer 1987, SiegelCausey & Downing 1987].
By moving and acting initially in close physical contact with the child, one becomes aware of "topographically minute behaviours" [Siegel-Causey et al. 1987, p. 33] and the principal caregiver may respond accordingly. It should be emphasized here, that "responding" does not necessary mean affirmatively. In the development of a person's predictability, it is highly important to learn when to expect "no" as an answer. With respect to the memory problems so manifest in these children, such activities e.g. moving [together] with the child along an "obstacle course" should be repeated very regularly and announced for instance by presenting the child with an object which will be used during the activity.
A similar procedure which we successfully applied was to characterize the principal caregiver by a typical object e.g. a scarf, earrings or a piece of clothing [s]he wears during a one-to-one situation with the child. [For further details: see Van Dijk 1986, Visser 1988].
In moving-acting together with the child the educator will become aware of the child's pervasive sensory-motor problems [dyspraxia] which has an enormous impact on communication and behaviour.4. Dyspraxia - communication and learned helplessness
The research findings on the relationship between dyspraxia and communicative skills demonstrated rather clearly how this "cognitive sensory-motor" function strongly influences the communicative competence of particularly the [low functioning] deaf-blind child. Being unable to properly carry out self help skills, such as putting on one's socks, zipping a bag, holding a pencil or colouring shapes, must have a devastating influence on the subject's feeling of competence. If a person working with these individuals comprehends the pervasive nature of this dysfunction [s]he will understand the following behaviour: the teacher presented two triangles she had drawn. one shape was already neatly coloured by her, the child [hearing and visually impaired] had to do the same with the other one. A crayon was presented to the child. He looked at it, gave it back to his teacher, banged his head and withdrew from the table. Again an episode was added to his long experience of failure. Many of these children will try to manipulate their caregivers' or teachers' hands, indicating the desire that they want to observe while the other carries out the task. Some of the individuals turn out to be very effective "manipulators": they become increasingly more successful in letting someone else do the task. If the person in the environment of the subject is willing to offer "help" [sometimes he is forced to do so by the child] the vicious circle is closed: the significant adult in the child's life becomes increasingly active and the handicapped subject increasingly passive. In the context of the theory of "locus of control": the individual perceives him/herself as unable to influence the events in his environment and feels controlled by them.
Encouraging the child to become active e.g. by means of rewards, has no sense if the tasks are not adjusted to the individuals' eupractic abilities. In order to facilitate the learning of [sensory] motor skills, we have advocated the carrying out of these tasks co-actively; this is carefully guiding the child's limbs [Van Dijk 1986].
A similar approach has recently been employed in teaching self-dressing skills to a severely retarded deaf-blind girl, age 11 years.
The therapy started with total hand-over-hand manual guidance in putting on a garment. Gradually the guidance was faded out completely. Reinforcement therapy was combined with this procedure [Sisson, Kilwein & Van Hasselt 1988]. Sometimes this "fading out" procedure is difficult to maintain, because in a normal daily living situation the subject may unexpectedly grasp the hands of his/her trainer and in this way acquire full assistance again. We have experienced this in teaching deaf-blind individuals to walk independently, without continuous prompting by the adult [e.g. giving a small push in the back, or taking the child by the hand]. An automatic prompting device had been constructed with a timer which gives the subject a "tap" when [s]he stops walking. Time intervals of independent walking have increased with training. When the device is withdrawn results are preserved [Lancioni, Van Dijk, Manders & Driessen 1988]. New devices e.g. for staying on task which allow adults "to stay away" from the child are under development. In the setting of the author [Institute for the Deaf, Sint Michielsgestel, the Netherlands] so-called "task-rooms" are designed to allow the deafblind individual to complete appropriate tasks independently. It has been found that tasks which were chosen on the basis of eupractic competence and which are repeated frequently and reinforced led to an unexpected level of independent functioning. Also play activities in which the objects were self-reinforcing (e.g. every time a coloured disk is manipulated it produces a bright colour pattern] stimulated independent play. It is reported that independent play in some individuals increased by 82% [Van Dijk, Carlin & Janssen 1989].
In relation to communication the eupractic ability of the individual is too often overlooked. The interest in communication systems for persons unable to speak is overwhelming [see for overview Kurnau, 1987].
According to Fristoe and Lloyd's survey the selection of a system for clinical use seems to be based more upon familiarity with a certain system than on knowledge of available options [Fristoe and Lloyd 1977]. In general there are two types of systems: aided communication techniques [the graphic systems such as Rebus Reading, Bliss and Makaton] and unaided techniques of sign language. Different sign language systems combined with aided forms of communication are widely used with multi-handicapped individuals, including the deaf-blind [Kates & Schein 1980, Shane & Wilbur 1980]. It seems obvious that selection of a particular non speech system should consider the potential user's eupractic ability. Our experiences in agreement with those of Shane and Wilbur, who warn against using signs exclusively for persons having mild to severe motor impairment [Shane et al. 1980, p. 29] .
These authors emphasize the motor component as such, which plays a role in competent signing and to a much lesser extent the user's eupractic ability, which contains cognitive elements as well, such as [motor] memory to retain the signs.
In reference to non-speaking autistic children, Wetherby and Prutting make a similar statement, namely that there have been few investigations of autistic children's profile of sensorimotor functioning in relation to communicative and linguistic development [Wetherby et al. 1984, p. 364].
In determining the motor components of sign structures it is important to make a distinction as to whether the hands actually touch the body or do not make contact. In our approach of severe dyspractic children and adolescents the sign system should be initially a "body-touching system". If an individual is unable to choose or differentiate the places to be touched, [s]he should be aided by wearing a "communication apron", with different colours and/or textures or a finger spelling glove. In general the signs to be used with persons with dual sensory disabilities, should be within their eupractic competence. If not, the subjects will withdraw from any initiative to communicate, which often, leads to the adverse effect of people in the subject's environment bombarding the individual with a continuous flow of signs.
In many instances it is more appropriate to refrain from the introduction of a sign system at all, and start developing a communication code which is exactly matched to the individuals capacities. It is our assumption that the extreme passivity of a number of deaf-blind individuals is partly attributable to the selection of an inappropriate code of communication.
One important point should be mentioned here. Presenting an individual with signs means that the so-called sequential memory is involved. This type of memory is highly associated with one's rhythmic ability and general level of language functioning [Van Uden, 1983], capacities underdeveloped in many multi-impaired individuals. This supports the view of considering "simultaneous" communication codes such as the use of [embossed] objects of reference, "tangible symbols" [Rowland et al., 1988] schematized pictures and...the written word, combined with pictures [iconic graphic system]. [See for further details on our approach: Writer 1987, p. 198-199].
To conclude this paragraph we would like to draw attention to the relationship between stereotypic behaviour and functional communication. This has been recently clearly demonstrated in autistic individuals. Results of the study of Dadds, Schwartz, Adam and Rose showed that low verbal skills in autistic children predict [a high] level of stereotypic behaviour, especially in low contact settings [Dadds et al. 1988]. It is generally agreed that stereotyped behaviour interferes with pro-social behaviour, task direction and cognition. Teaching these individuals a limited number of functional signs, decreased their stereotypic behaviour significantly.5. Some case studies
In this final section of this paper, we will present a number of cases, which fall within the category of moderately to severely retarded individuals. The results of applying appropriate modes of communication is well demonstrated here. The subjects illustrate that with an increase in communicative ability, the strong preference for stereotyped [motor] acts decreases. [See Table 1 - 7.] This suggests a causal relationship. It can be noted too, that although many of the stereotyped behaviour patterns were not completely extinguished, they became less intense. The treatment theory advocated by us was that many of these types of behaviour are essentially communicative in nature, but should be gradually replaced by more appropriate means. One may notice that a great variety of communicative means are used, according to the relative strengths of the individual. These ideas have only recently been acknowledged by researchers in adjacent areas of study. In relation to autism, Prizant and Wetherby wrote:...a significant impact on communication enhancement is the presentation of information through the visual spatial modality, using pictures, picture symbols and/or written words... [Prizant et al. in press].
It should be noted that it has taken many years of education of these persons to come to the conclusion that sometimes "aberrant behaviour patterns" serve a meaningful purpose for a dual sensory deprived person to signal the need for stimulation, proximity and comfort.
The true educator for these persons is [s]he who perceived this and is able to respond accordingly. In other words who can really come into conversation with the persons.
Appell, M.W. . Infant stimulation programming for the deafblind. In E.L. Lewe11 & C.C. Rouin [Eds.], State of the art. Perspectives on serving deaf-blind children [pp. 149-165]. Sacramento: California State Department of Education.
Bandura, A. . Social learning theory. Englewood Cliffs: Prentice Hall, Inc.
Bowlby, J. [1969/1982]. Attachment and loss, Vol. 1: Attachment [2nd ed]. New York: Basic Books.
Coll, J., Dumoulin, M. & Souriau, J. . L'examen auditif et les moyens de communication chez le sourd-aveugle. Bulletin d'audiophonologie, 1, 16-52.
Curtis, W.S., Donlon, E.T. & Tweedie, D. . Learning behavior of deaf-blind children. Education of the visually handicapped, 7, 40-46.
Dodds, M., Schwartz, S., Tracey, A. & Rose, S. . The effects of social context and verbal skill on the stereotypic and taskinvolved behaviour of autistic children. Journal of child psychology and psychiatry, 29, 669-676.
Dunlap, W.R. . A functional classification system for the deafblind. American annals of the deaf, 130, 236-243.
Fox, M.A. . The effects of combined vision and hearing loss on the attainment of developmental milestones, The University of Western Ontario [Canada].
Fristoe, M. & Lloyd, L. . Manual communication for the retarded and others with severe impairment: a resource list. Mental retardation, 15, 18-21.
Hammer, E.K. . Research issues in educating visually handicapped persons with multiple impairments. In M.C. Wang, M.C. Reynolds, & H.J. Walberg [Eds.], Handbook of special education. Research and practice. Vol. 3. New York: Pergamon Press.
Harlow, H.F. . Maternal behavior in socially deprived rhesus monkeys. Journal of abnormal and social psychology, 69, 345-354.
Kates, L. & Schein, J.S. . A complete guide to communication with deaf-blind persons. Silver Spring, Md.: National Association for the Deaf.
Kimmel, H.D. . Intelligence and the orienting reflex. In M.P. Friedman, J.P. Das & N. O'Connor [Eds.], Intelligence and learning. Tampa: University of South Florida.
Kurnau, C.C. . Non-vocal communication systems: a critical survey. In W. Yule & M. Rutter [Eds.], Language development and disorders. London: McKeith Press.
Lamendella, J.T. . The limbic system in human communication. In H. Whitaker & H. Whitaker [Eds.], Studies in neurolinguistics. New York: Academic Press.
Lancioni, G.E., Van Dijk, J., Driessen, M. & Manders, N. . An automatic prompting instrument to increase task-related responding in low-functioning individuals. Journal of behaviour therapy and experimental psychiatry, 19, 267-273.
Meshcheryakov, A. . Awakening to life. Forming behaviour and the mind in deaf-blind children. Moscow: Progress Publishers.
Nielsen, L. . Pedagogical methods and materials helping severely multihandicapped blind children to develop. In: L. Palmer, S. Raynoi & J. Urban [Eds.], Proceedings second international symposium on visually handicapped infants and young children: Birth to seven [pp [121-124]. Boston: The New England.
Prior, M.R. . Biological and neuropsychological approaches to childhood autism. British journal of psychiatry, 150, 8-17.
Rowland, C. & Schweigert, Ph. . Tangible symbol systems. Eugene: Oregon Research Institute.
Salzen, E.A. . Social attachment and a sense of security. In M. von Cranach, K. Foppa, W. Lepenies & D. Ploog. Human ethology claims and limits of a new discipline. Cambridge: Cambridge University Press.
Seys, D.M. & Duker, P.C. . Effects of a supervisory treatment package on staff-mentally retarded resident interactions. American journal of mental deficiency, 90, 388-394.
Shane, H.C. & Wilbur, R.B. . Potential for expressive signing based on motor control. Sign language studies, 29, 331-348.
Siegel-Causey, E. & Downing, J. . Nonsymbolic communication development. In L. Goetz, D. Guess & K. Stremel-Campbell [Eds.], Innovative program design for individuals with dual sensory impairments [pp.15-48]. Baltimore/London: Paul H. Brookes Publishing Co.
Sisson, L.A. . Single-case analysis and social validation of behavioral interventions with severely and profoundly handicapped deaf-blind children and youth. Pittsburgh University of Pittsburgh.
Sisson, L.A. & Kilwein, M.L. & Van Hasselt, V.B. . A graduated guidance procedure for teaching self-dressing skills to multihandicapped children. Research in developmental disabilities, 9, 419-432.
Sokolov, E. . Neural models and the orienting influence. In M. Brazier [Ed.], The central nervous system and behavior: III. New York: Macy Foundation.
Van de Biggelaar, B., Verwijst, D. & Heynen, I. . Case-studies on intrinsic motivation and feeling of competence. In Proceedings of the European conference on the education and management of the deaf-blind [53-57]. Brugge: Anna Temmerman Association.
Van Dijk, J.P.M. . Motor development in the education of deafblind children. In Proceedings of the conference on the deafblind, Denmark [pp 41-47]. Boston: Perkins School for the Blind.
Van Dijk, J.P.M. . Rubella handicapped children. The effects of bi-lateral cataract and/or hearing impairment on behaviour and learning. Lisse: Swets & Zeitinger B.V.
Van Dijk, J.P.M. . An educational curriculum for deaf-blind multihandicapped persons. In D. Ellis [Ed.] Sensory impairments in mentally handicapped people [pp. 375-382]. London: Croom-Helm.
Van Dijk, J.P.M., Carlin, R. & Janssen, M. . Stereotyped behaviour in rubella-deaf and deaf-blind people. Deaf-blind education, 3, 8-10.
Van Uden, A.M.J. van . Diagnostic testing of deaf children: the syndrome of dyspraxi a. Lisse: Swets & Zeitlinger B.V.
Visser, A. . Educational programming for deaf-blind children. Some important topics. Deaf-blind education, 2, 4-7.
Wetherby, A.M. & Prutting, C.A. Profiles of communicative and cognitive social abilities in autistic children. Journal of speech and hearing research, 27, 264-377.
Writer, J. . A movement - based approach to the education of student who are sensory impaired/multihandicapped. In L. Goetz, D. Guess & K. Stremel-Campbell [Eds.], Innovative program design for individuals with dual sensory impairments. Baltimore/London: Paul H. Brookes Publishing Co.