Language skills in developmentally disabled children

Language measures of receptive and expressive vocabulary, story telling, and immediate verbal memory, as well as two perceptual tests, were administered to a group of developmentally disabled children, and three groups of normal children, one matched for chronological age, one for mean length of utterance, and one for performance on one of the perceptual tests. When diagnostic subgroups of “autism,” “childhood schizophrenia,” and “other severe disturbance” were formed using standard diagnostic tools, no language differences were found between diagnostic subgroups. When compared with the normal control groups, many of the language skills of the entire group of disabled children, and of the autistic children alone, were rather evenly delayed, showing only a relative sparing of the naming function, and a relative deficit on immediate verbal memory. Furthermore, a high correlation was found in a small subsample between the difficulty levels of morphemes in the disabled children and those reported for young normal children. Experienced special-education and early-childhood teachers could not discriminate the stories of the disabled children from those of young normal children. Analysis of the disabled children's error strategies, however, revealed features of their language not found in normal children's language: (1) extreme perseveration in test answers and stories, (2) attention to minor features of test stimuli, and (3) failure to adopt alternate, flexible communicative strategies. We conclude that the language acquisition of the developmentally disabled children is delayed but not deviant in its semantic and syntactic competence, and that current diagnostic practice does not differentiate linguistically distinct subgroups. We further argue that where developmentally disabled children do exhibit aberrant features of language, such deviance parallels similar features in other cognitive skills, and is not unique to language.     

The generality of overselectivity in developmentally disabled children

A growing body of research suggests that low Mental Age (MA) autistic and retarded children show a unique stimulus control deficit, one that may cause many or most of their behavioral deficiencies. This problem, stimulus overselectivity, is evidenced when a child responds only to a restricted portion of the stimulus environment when compared with normal children. The purpose of this study was to assess whether this overselectivity is general across situations or whether it is restricted to certain stimulus/task conditions. Eight autistic children, who evidenced overselectivity on a preassessment task, and 8 normal children with similar MA levels participated. All children were trained on 3 tasks to determine if overselectivity varied as a function of different stimulus conditions. Each of the 3 tasks involved training a child to respond to (i.e., touch) a card containing a circle (S +) and to avoid a blank (S ?) card. In each case, the circle comprised a series of dots. The difference between the 3 circles (tasks) was the distance between the successive dots making up each circle. Also, in the minimal separation condition the dots were smaller in size and greater in number than in the larger separation conditions. Of concern was whether autistic children learned about the gestalt (i.e., the circle), which required attention to multiple cues, or whether children would overselect and respond to the dots. The results showed that (1) stimulus overselectivity was found not to be a generalized deficit in autistic subjects; instead, it varied as a function of the stimulus variables; and (2) the stimulus variables manipulated in this study similarly influenced the responding of both normal and autistic children. The implications of these data for a theory of overselectivity are discussed.     

Relationship between intellectual status and reading skills for developmentally disabled children

The relationship between WISC-R Full Scale IQ and scores on the Woodcock Reading Mastery Tests were explored for 80 developmentally disabled children. While the children's reading skills correlated moderately and significantly with intellectual status, abstract reading skills, e.g., word comprehension, correlated more highly with Full Scale IQ than did concrete ones, e.g., word identification. The development of concrete learning patterns by such children was discussed, with an emphasis on the emotional importance of these learning styles to the children and their families.     

Sensory Extinction: A procedure for eliminating self-stimulatory behavior in developmentally disabled children

This study was designed to investigate the role of sensory reinforcement in the motivation of self-stimulation. If self-stimulatory behavior is maintained by its sensory consequences, such as the proprioceptive, auditory, or visual stimulation it produces, then such behavior should extinguish when those sensory consequences are not permitted. The present study introduces a new procedure, Sensory Extinction, in which certain sensory consequences are masked or removed, to examine whether self-stimulation is operant behavior maintained by sensory reinforcement. The effectiveness of Sensory Extinction was assessed by a reversal design for each of three autistic children, and the results showed the following. First, self-stimulation reliably extinguished when a certain sensory consequence was removed, then increased when that consequence was permitted. This was replicable within and across children. Second, different Sensory Extinction procedures were required for different self-stimulatory behaviors, since the sensory reinforcers supporting them were idiosyncratic across children. Finally, regarding clinical gains, the data suggest that Sensory Extinction may be a relatively convenient and rapid alternative for the treatment of self-stimulation. The present findings extend the efficacy of extinction as a behavior-modification technique to instances in which the reinforcer is purely sensory. The implications of these results for the treatment of other forms of deviant behavior are discussed.     

Prosodic aspects of motherese: effects on gaze and responsiveness in developmentally disabled children

This study was conducted to examine the effectiveness of using voice tones (prosody) typical of "motherese" (O. K. Garnica, 1977, in C. E. Snow & C. A. Ferguson (Eds.), Talking to Children: Language Input and Acquisition, pp. 63-88, Cambridge: Cambridge Univ. Press) on responsiveness and eye gaze in children with severe handicaps. Specifically, two conditions, "motherese" and "conversational" voice tones, were compared. The current study presents data from naturalistic observations of six children, and controlled experimental manipulations with four children. The results of the naturalistic observations in Study 1 suggested a positive relationship between the use of voice tones typical of "motherese" and responsiveness and eye gaze. Further analysis using an alternating treatments design in Study 2 revealed similar results. Specifically, the use of prosody associated with "motherese" showed increased levels of eye gaze when compared to the use of "conversational tones." The results suggest the importance of considering normal development in analyzing social and teaching interactions between teachers and severely handicapped children.     

Respect for the developmentally disabled and forgoing life-sustaining treatment

A developmentally disabled person should be treated at all times as a unique individual and not as some anonymous "disabled person." The developmentally disabled should not be subjected to invasive medical treatment that is unduly burdensome or nonbeneficial, or be forced to endure a quality of life not meaningful to them as individuals. They have a right to refuse or accept treatment that a surrogate must exercise on behalf of each individual in a responsible and careful manner. Three cases and a preliminary approach to the ethical analysis of decisions to allow developmentally disabled persons to die by forgoing medical treatment are offered. The "best interests" of a developmentally disabled individual, properly understood, can serve as a useful and ethically defensible standard for determining the ethical propriety of surrogate decision making about forgoing life-sustaining medical treatment of the disabled.     

Medical problems,maladaptive behaviors,and the developmentally disabled

Research has shown that aberrant behaviors of people with developmental disabilities have multiple determinants; of these, medical problems and their potential relations to aberrant behaviors, have been, for the most part, not studied. This retrospective study examined the relations of 26 acute medical treatements to the aberrant behaviors of 10 elderly people with developmental disabilities. Results showed that 73.1% of the aberrant behaviors decreased in frequency after medical treatments. The study suggests the importance of acute medical problems and treatments as possible factors in the occurrence of aberrant behaviors in this population.     

Factor analysis of Wechsler Adult Intelligence Scale-Revised in developmentally disabled persons

The results of previous studies on the factorial structure of Wechsler Intelligence Scales are somewhat inconsistent across normal and pathological samples. To study specific clinical groups, such as developmentally disabled persons, it is useful to examine the factor structure in appropriate samples. A factor analysis was carried out using the principal component method and the Varimax orthogonal rotation on the Wechsler Adult Intelligence Scale (WAIS-R) in a sample of 203 developmentally disabled persons, with a mean age of 25 years 4 months. Developmental disability ranged from mild to moderate. Partially contrasting with previous studies on normal samples, results found a two-factor solution. Wechsler's traditional Verbal and Performance scales seems to be more appropriate for this sample than the alternative three-factor solution.     

Treatment of chronic food refusal in a young developmentally disabled child

Chronic food refusal is a common problem among young children with developmental disabilities. Children with chronic food refusal may require supplemental tube feedings or parental feedings. A multicomponent treatment package consisting of escape–avoidance extinction, shaping and positive reinforcement was effective in establishing a normal oral feeding pattern with a 1.5 years old developmentally disabled child who was fed by gastrostomic tube. Treatment effects generalized to the home setting and were maintained during follow‐up. After treatment, tube‐feeding was discontinued. Copyright © 1999 John Wiley & Sons, Ltd.     

Long-term follow-up study of children developmentally retarded by early environmental deprivation

In 1972, two children representing a case of severe developmental retardation were discovered and taken into custody. The children, an older sister (referred to as F) and a younger brother (referred to as G), were found to have achieved no more than the physical and mental age level normal to children 1 year of age or less, in spite of their actual respective chronological ages of 6 and 5. Investigation revealed that the children's developmental retardation was due both to extreme social isolation and to complex deprivation. By following their sensorimotor, linguistic, cognitive, and socio-emotional development from the time of discovery to the date of this writing, we have found that their physical and motor development or recovery has proceeded smoothly, whereas their linguistic and cognitive development has continued to show such weaknesses as defective functioning of internal speech (Vygotsky, 1962) and poor ability to deal with abstract, linguistic subjects. F and G have continued to exhibit a tendency toward undersocialization, but this has at times been rather a positive factor in the process of attaining ego identity during adolescence, especially for G, serving to protect him from unreasonable social pressures to conform to group behavior. In combination with other cases of severe deprivation, the case of F and G holds some interesting implications for theories of human development, particularly the notion of critical periods.     

Naming of object-drawings by dyslexic and other learning disabled children

On the Oldfield-Wingfield Picture-Naming Test, sensitive to subtle chronic dysphasia in adults, dyslexic children name fewer pictures correctly. Even when correct on words with less than 30 per million frequency of occurrence, they perform more slowly than do nondyslexic subjects suffering from minimal brain dysfunction (MBD) or normal controls. However, there is no evidence for “perceptual impairment” underlying dyslexic subjects' low scores and prolonged latencies, as the distribution of their errors is similar to that of normal children. Rather it is the nondyslexic MBD group which produces a high percentage of wrong names, suggestive of mistaking the pictured stimuli for other, visually similar, objects.     

Arranging a residential environment for the developmentally disabled to generate and maintain verbal behavior

A specialized residential unit was assembled at a state residential facility for mentally retarded residents in order to provide services for individuals who lacked functional speech but who were capable of learning manual signs. Program development focused on four areas. First, a routine was designed to engage residents in functional training activities throughout the day. Second, opportunities to teach signed verbal behavior within all components of the routine were identified. Third, structured training sessions were developed to augment training within normal daily living activities. Fourth, multiple staff training strategies were initiated. Initial outcome data indicate that signing skills of both staff and residents improved.     

Reading deficits in learning disabled children

The purpose of this study was to determine whether LD children exhibited problems in the processes of attention, memory, or syntactical awareness when decoding written prose. Eighteen LD children and 18 normal controls were matched for initial word recognition skills. Subjects were then trained to read a list of individual words to criterion. Subsequently, they were tested on their ability to decode the same words in paragraph form, presented both immediately after training, and then again one week later. Half the children read paragraphs following standard English syntax, while the other half read a syntactically scrambled version of the same paragraph. The results indicated that a major contributing factor in the reading (decoding) difficulties demonstrated by the LD children derived from problems of acquisition and retrieval from long-term memory storage. The results were discussed in terms of their implications for the developmental lag theory of learning disabilities.     

Rate of information segregation in developmentally dyslexic children

Slowed processing of sequential perceptual information is related to developmental dyslexia. We investigated this unimodally and crossmodally in developmentally dyslexic children and controls ages 8-12 years. The participants judged whether two spatially separate trains of brief stimuli, presented at various stimulus onset asynchronies (SOA) in one or two senses, were synchronous or not. The stimulus trains consisted of light flashes in vision, clicks in audition, and indentations of the skin in the tactile sense. The dyslexic readers required longer SOAs than controls for successful performance in all six comparisons. The crossmodal spatiotemporal resolution of the groups differed more than unimodal performance. The dyslexic readers' segregation performance was also less differentiated than that of the controls. Our results show that not only sensory but also polysensory nonverbal information processing is temporally impaired in dyslexic children.