2014 Volume 55 Issue 1 Pages 17-25
This study analyzed factors related to theory of mind (ToM) development in 12 hearing-impaired children aged 4-7 years whose average hearing level was 75-7 dB (46.2-110 dB, 1 SD 22.7), compared to 12 hearing preschoolers 4-5 years old. Two ToM tasks, the “explanation of action task” and “false belief task,” were evaluated. The results revealed no difference between hearing-impaired subjects and hearing subjects in ability to use mental state to explain causes of human action. On the other hand, hearing-impaired subjects delayed significantly in the false belief task compared to hearing subjects. Hearing-impaired children were likely to delay in meta-representational development, i.e. the ability of representational understanding of others' mind from the others' viewpoint. Hearing-impaired subjects had a higher language development level for acquiring meta-representational ability than hearing subjects. These results suggest that meta-representational development of hearing-impaired children is influenced more by hearing level, language development age or syntax-appropriate utterances than by the hearing threshold level of the aided or implanted ear or the mean length of utterance in morphemes. This study indicated the development of meta-representational ability in hearing-impaired children and the factors related to acquiring that ability. The results are useful as fundamental data for constructing language training programs.