Theory of mind in children with cochlear implants: Comparison with age- and sex-matched children with normal hearing

Theory of mind (ToM) is a crucial ability for maintaining normal social interaction and is directly related to language ability. This study was performed to compare ToM between children with congenital hearing loss who have received cochlear implantation (CI) and those with normal hearing (NH).

Case-control study design.

One hundred children, aged 2-12 years, participated: 50 children who received CI before 36 months of age (CI group) and one-to-one age- and sex-matched children with normal hearing (NH group). All children underwent tests to examine receptive language ability and ToM. Receptive language was measured using the Receptive and Expressive Vocabulary Test, and ToM was measured using the Theory of Mind Task Battery (ToM-TB). The scores of the two tests were compared between the CI and NH groups.

The ToM-TB score in the CI group correlated positively with age and receptive language score. ToM-TB scores did not differ significantly between children in the CI group who achieved normal receptive language and the NH group. However, these children in the CI group scored lower than those in the NH group on some advanced ToM tasks that require the ability to understand second-order emotion, message-desire discrepancy, or second-order false belief.

This case-control study found that children with CI who achieve normal receptive language ability have ToM that is similar to that in children with NH. However, these children exhibited weakness in advanced ToM skills. Interventions to facilitate the development of advanced ToM are needed for children with CI.