Cognitive functioning of prelingually deaf children

Abstract

The thought process of profoundly and severely prelingually deaf children were studied in a field situation, to determine both general mechanisms and individual differences in information processing. The central concern was whether individuals who were largely deprived of normal means of verbal processing make particular use of visual, articulatory and kinaesthetic cues. The perception and immediate recall of visually presented letters were investigated (Experiments 1-4). All the deaf subjects appeared to be relying heavily on visual cues, whilst articulatory coding was employed only by those most able to articulate intelligibly. The use of visual cues was also found in a lexical-decision task when graphemically similar word pairs were processed significantly faster than either phonemically similar word-pairs were processed significantly faster than either phonemically similar or control word-pairs (Experiment 5). When similarity of sign equivalent wan manipulated (Experiment 6), the deaf subjects processed the word-pairs with sign equivalents significantly faster than those without sign equivalents. In a sentence-recall task, a written version of sign language (SL) was recalled significantly better than either “deaf English” or standard English (SE) (Experiment 7). The deaf subjects were also able to understand short stories written in SL significantly better than those written in SE (Experiemnt 8). In the final experiment (Experiment 9), kinaesthetic feedback provided by the active use of fingerspelling significantly improved the deaf children’s retention of new spelling patterns. The experimental evidence suggested that the cognitive system of the deaf children was structurally different from that of normally hearing children, developing as it does primarily through visual input. It was visually oriented, backed up by additional kinaesthetic, and, in some cases also by articulatory, information processing. In the light of the present findings, the implications for cognitive development of the use of standard English as the 'official' language of classroom instruction in deaf schools are discussed. Throughout this study there was considerable evidence of marked individual differences in the communicative abilities of the deaf children. Since these differences clearly constituted important experimental variables, it is suggested that, in future studies, there should be greater awareness of the importance of such differences within experimental populations.