Eye gaze reveals that children with cochlear implants have difficulty processing subject-verb agreement

This study investigates comprehension of subject-verb agreement by German speaking children with cochlear implants (CIs) (n=31, 7;1-12;4, mean: 9;6) and children with normal hearing (NH) (n=36, age 7;5-10;9, mean: 9;0). Previous research has shown that young children with NH have problems in the interpretation of verb inflection. For children with CIs, the subtle verb inflection information may be even harder to detect and comprehend. In a picture selection task with eye-tracking we found that children with CIs are less sensitive to number information provided by the verb (e.g., Sie malt/malen die Prinzessin ‘she/they paint(s) the princess) than children with NH (CI: 85% correct, NH: 96% correct). Children with higher working memory scores are better in identifying the number of the subject. In contrast to children with NH, children with CIs identify the number of the subject earlier and better in sentences with strong verbs, where the singular and plural verb forms are perceptually more distinctive, than in sentences with weak verbs. Thus both cognitive and perceptual factors play a role in the processing of subject-verb agreement by children with CIs.