Advances in Cognition, Education, and Deafness

Language and Cognitive Development of Deaf and Hearing Twin Sisters

Language and Cognitive Development of Deaf and Hearing Twin Sisters Barbara R. Schirmer T he child's ability to symbolize is manifested in the emergence of language and imaginative play during the second year of life. As aspects of the child's developing semiotic function (Piaget 1962), both language and play require that the child be able to represent reality in thought. Evidence for a developmental sequence in imaginative play that corresponds with early language development comes primarily from studies of normally developing children (Fein 1981; McCune-Nicolich 1981; Rubin & Pepler 1982; Westby 1980). Studies of handicapped children have confirmed the existence of relationships between imaginative play and language development (Casby & Ruder 1983; Lombardino & Sproul 1984; Owings & Workman 1983; Terrell, Schwartz, Prelock & Messick 1984). Investigations into the play of hearing-impaired children have shown that delays in one system correspond to delays in the other (Casby & McCormack 1985; Higginbotham & Baker 1981; Mann 1984). The relationship between language and cognitive development is of central concern to educators of hearing-impaired youngsters. The purpose of the present study was to investigate this relationship within the special environment of twins, one deaf and one hearing. The specific research questions were: (1) What is the pattern of sameness or difference in their language and cognitive development, and (2) What aspects of their interaction enhance or impede language and cognitive development? SUBJECTS AND PROCEDURE The subjects were one pair of identical twin sisters who were 4 years 5 months old. Dena had normal hearing. Jill had a profound sensorineural hearing loss 205 206 Cognitive Development that had been diagnosed at 18 months of age. She had no other handicapping condition. Two 60-minute sessions were used to observe the twins. The first session took place in a clinical setting in which Jill interacted individually with the investigator . The second session took place in the children's home 13 days later. The materials were designed to elicit spontaneous, representative, expressive language and to encourage imaginative play. Included were a picture book of The Three Bears with no written words and three sets of Fisher-Price toys (doll house, farm, and garage) with miniature people. SEMANTIC AND SYNTACTIC LANGUAGE ANALYSIS Brown (1973) defined five stages of child language development that he considered to be central to the child's acquisition of meanings and forms. Within each stage he postulated the development of a major language process that accounted for much of the power within language and whose development in child language it had been possible to chart. Jill produced 92 utterances in the individual session. Her mean length of utterance (MLU) was calculated to be 1.49, which placed her in Brown's Stage I language (1.00-1.99). Of the total corpus, 58.7% were single-morpheme utterances and 40% were two-morpheme utterances. She used six of the eight twoterm semantic relations identified by Brown as indicative of Stage I language. She also demonstrated use of several Stage II grammatical morphemes. Of the Stage III modalities of the simple sentence, she used eight yes/no questions (use of voice intonation only without sentence transformation) but no wh-questions (questions requiring that a constituent be specified), no negatives, and no imperatives. She used no Stage IV embedding of one sentence within another and one Stage V coordination of a simple sentence with the conjunction but. Jill's eighteen utterances in the joint session with Dena demonstrated considerably less language than she had produced in the individual session. Of this total, 77.8% were single-morpheme utterances and 22.2% were two-morpheme utterances. She used one of the Stage I 2-term semantic relations and no Stage III grammatical morphemes. She used no features from the other three stages. Her MLU in this session was 1.33. Dena produced 276 utterances in the joint session. Her MLU was 6.01, which placed her well beyond Stage V language (3.75 +). She demonstrated the use of all the Stage III modalities. She also used the three types of embedded sentences from Stage IV, including object-noun phrase complements, embedded wh-questions , and relative clauses. Of the Stage V coordinators, Dena used and, because, but, and so. ANALYSIS OF FUNCTIONAL LANGUAGE USE Halliday (1975) considered the learning of language to be essentially the learning of a semantic system. He found that this content-expression system is well under Language and Cognitive Development ofDeaf and Hearing Twin Sisters...