AN ALTERNATING TREATMENTS COMPARISON OF ORAL AND TOTAL COMMUNICATION TRAINING WITH MINIMALLY VERBAL RETARDED CHILDREN

This study was a comparison of the effects of oral speech with total communication (speech plus sign language) training on the ability of mentally retarded children to repeat 4-word sentences. Three children were chosen who used single words to communicate but who did not combine words into complete sentences. Three sentence pairs were trained, with each pair having one sentence trained using oral methods and an equivalent one trained using the total communication approach. Both training procedures involved chaining sentence parts, reinforcement, and prompting. Oral methods involved presenting vocal stimuli and requiring vocal responses whereas total communication methods involved presenting vocal and signed stimuli and requiring vocal and signed responses. For the initial sentence pair with each child, an alternating treatments design was used to determine the relative efficacy of the two language training approaches. This was repeated with a second and third sentence pair using a multiprobe technique within a multiple baseline design. Results pointed to the superiority of the total communication approach in facilitating sentence repetition. Possible explanations of these results are offered and the utility of the alternating treatments experimental design is discussed.     

TRAINING AND GENERALIZATION OF REACH-GRASP BEHAVIOR IN BLIND,RETARDED YOUNG CHILDREN

The effects of a graduated prompting treatment procedure were analyzed in three phases of an experiment on the training and generalization of reaching-grasp responding in 2- to 4-year-old blind, severely or profoundly retarded children. In Phase 1, we used a multiple-baseline across-subjects design to investigate the effectiveness of the treatment on midline reach-grasp responding. In Phase 2, we used a reversal design to investigate the effects of repeated implementations and withdrawals of the treatment. In both phases, generalization to right and left positions was measured. In Phase 3, in a multiple-baseline across-responses design, the treatment was implemented in right and left positions. Also in Phase 3, shift of stimulus control from toy-sound to verbal instructions was measured. The results showed that (a) the graduated prompting procedure was effective in training reach-grasp responding in all three children; (b) for one child, the effects were durable over repeated applications of the treatment procedure, but were not maintained during withdrawals; (c) for another child, the treatment procedure was effective in teaching reach-grasp responding in all three positions; and (d) for the same child, training of reach-grasp responding generalized to toys presented without sound, given only the verbal instruction.     

Delayed reinforcement as an indiscriminable contingency in verbal/nonverbal correspondence training

We investigated the programming of generalization and maintenance of correspondence between verbal and nonverbal behavior in a preschool setting. Four children participated in a series of multiple-baseline designs. In Experiment 1, delayed reinforcement of verbal behavior effectively controlled maintenance of correspondence with previously trained responses and also resulted in generalization of correspondence to one untrained response. As the latter effect was limited, Experiment 2 was a further assessment of the effects of delayed reinforcement of generalization of correspondence to untrained responses, and consistent generalization was shown. Experiment 2 also showed that generalization, if lost, could be recovered through use of "booster training," in which the original contingencies were reinstated for a brief period. Experiment 3 provided replications, with two additional children, of the effects of delayed reinforcement on maintenance of correspondence. Results are discussed in terms of using delayed reinforcement as an indiscriminable contingency.     

Infant sensitivity to figural coherence in biomechanical motions

Two experiments assessed infant sensitivity to figural coherence in point-light displays moving as if attached to the major joints of a walking person. Experiment 1 tested whether 3- and 5-month-old infants could discriminate between upright and inverted versions of the walker in both moving and static displays. Using an infant-control habituation paradigm, it was found that both ages discriminated the moving but not the static displays. Experiment 2 was designed to clarify whether or not structural invariants were extracted from these displays. The results revealed that (1) moving point-light displays with equivalent motions but different topographic relations were discriminated while (2) static versions were not, and (3) arrays that varied in the amount of motion present in different portions of the display were also not discriminated. These results are interpreted as indicating that young infants are sensitive to figural coherence in displays of biomechanical motion.     

Trading relations in the perception of speech by 5-year-old children

Five-year-old children were tested for perceptual trading relations between a temporal cue (silence duration) and a spectral cue (F₁ onset frequency) for the “say-stay” distinction. Identification functions were obtained for two synthetic “say-stay” continua, each containing systematic variations in the amount of silence following the /s/ noise. In one continuum, the vocalic portion had a lower F₁ onset than in the other continuum. Children showed a smaller trading relation than has been found with adults. They did not differ from adults, however, in their perception of an “ay-day” continuum formed by varying F₁ onset frequency only. The results of a discrimination task in which the two acoustic cues were made to “cooperate” or “conflict” phonetically supported the notion of perceptual equivalence of the temporal and spectral cues along a single phonetic dimension. The results indicate that young children, like adults, perceptually integrate multiple cues to a speech contrast in a phonetically relevant manner, but that they may not give the same perceptual weights to the various cues as do adults.     

A comparison of monocular and binocular depth perception in 5- and 7-month-old infants

Monocular depth perception was compared with binocular depth perception in 5- and 7-month-old infants. Reaching was used as the dependent measure. Two objects, identical except in size, were presented simultaneously to each infant. The smaller object was within reach for the infants while the larger object was just beyond reach. The two objects subtended equal visual angles from the infants' observation point. With binocular presentation, 96% of the 7-month-olds' reaches and 89% of the 5-month-olds' reaches were for the nearer object. With monocular presentation, 58% of the 7-month-olds' reaches and 65% of the 5-month-olds' reaches were for the nearer object. The reaching preferences observed in the monocular condition indicated sensitivity to monocular depth information (motion parallax, accommodation, and relative size information were available). Binocular viewing, however, resulted in a far more consistent tendency to reach for the nearer object. This result suggests that the infants' perception of the objects' distances was more veridical in the binocular condition than in the monocular condition.     

On the basis of early transitivity judgments

This research had two aims. The first was to test three explanations of performance on N-term series tasks by young children: the labeling model of B.DeBoysson-Bardies and K. O'Regan (1973), Nature (London), 246, 531–534, the sequential-contiguity model of L. Breslow (1981, Psychological Bulletin, 89, 325–351), and the ordered array or image model of C. A. Riley and T. Trabasso (1974, Journal of Experimental Child Psychology, 17, 187–202). In the first experiment, 5-year-old children were taught additional premises which would interfere with labeling and sequential-contiguity processes, but not with forming an ordered array. Reasoning performance was essentially comparable to previous results with the paradigm, thus supporting the ordered array model. The second aim was to reexamine children's ability to learn sets of premises which can be assembled into an ordered array, since there was reason to believe that previous studies had created false positives. In the second experiment, 3- to 7-year-old children were taught either overlapping (a > b, b > c, …) or nonoverlapping (a > b, c > d, …) premises. Overlapping premises can be integrated into an ordered array (a, b, c, d, e), but nonoverlapping premises cannot. However, the overlapping condition proved more difficult, and the success rate for preschoolers ($\text{3}\text{1}\text{2}\text{-}\text{to 4}\text{1}\text{2}\text{-year-olds}$) was of zero order. This raises doubts about their ability to learn a set of premises of the kind required for transitive inference. These doubts were strengthened by the third experiment which showed that when premises were not presented in serial order, preschool ($\text{3}\text{1}\text{2}\text{-}\text{to 4}\text{1}\text{2}\text{-year-old}$) children could not learn the premises of an N-term series task.     

More precisely defining and measuring the order-irrelevance principle

R. Gelman and C. Gallistel (1978, Young Children's Understanding of Number, Cambridge, MA: Harvard Univ. Press) use two definitions of the order-irrelevance principle interchangeably: (1) count tags do not have to be assigned in a fixed order and (2) the order in which elements of a set are enumerated does not affect the cardinal designation of the set. A study involving 107 kindergarten and first grade children indicates that the two are actually distinct concepts. Apparently, a willingness to arbitrarily assign tags is a developmentally less sophisticated ability than--and hence does not necessarily imply--an ability to predict that differently ordered counts produce the same cardinal designation. Thus it appears that evidence of the second ability is necessary to infer a full understanding of the order-irrelevance principle. The first ability alone implies what might better be termed an "order-indifferent tagging scheme." Suggestions for measuring and further researching the order-irrelevance principle are discussed.