Language, mental state vocabulary, and false belief understanding in children with cochlear implants.

Purpose: This study examined false belief understanding and its predictors in school-age children who are deaf with cochlear implants and who use spoken language.

Method: False belief understanding was measured through an explanation-of-action task in 30 children between the ages of 3 and 12 years who used cochlear implants. Children told a wordless story from which expressive syntax and vocabulary scores were obtained. Scores on the false belief explanation task were then correlated with a variety of language and vocabulary variables, and regression analyses were completed to ascertain significant predictors of theory of mind (ToM) performance.

Results: Children's false belief explanation of anomalous action was best predicted by age; general language ability; and spontaneous use of mental state vocabulary, specifically, cognitive vocabulary. Even the youngest children demonstrated awareness of others' mental states and made reference to them in explaining mistaken actions, supporting the assertion by M. Marschark, V. Green, G. Hindmarsh, and S. Walker (2000) that children who are deaf are not lacking a ToM.

Clinical Implications: Results of this study suggest that ToM maturation in deaf children might be facilitated by developing general spoken language skills as well as understanding and using cognitive and emotional language. These findings might also extend to children with normal hearing who are also at risk for ToM deficits (e.g., children on the autistic spectrum and children with pragmatic language delays).