Sentence comprehension following agenesis of the corpus callosum.

The sentence comprehension skills of a 6-year-old girl with callosal agenesis were compared to skills of three other children matched for age and verbal IQ. Sentence-picture matching and acting out tasks were used with reversible active, passive, and center-embedded relative clause sentences. The acallosal subject showed a deficit in syntactic comprehension. The difficulty was due to a failure to assign correct semantic roles to some sentence forms, not to a lack of ability to discriminate among the sentence forms. The data are consistent with a previous report by M. Dennis (1977, In Topics in child neurology, pp. 189-212) that in acallosal subjects syntactic comprehension can be adversely affected. Because this acallosal subject is only 6 years old, follow-up studies will be needed to determine whether she eventually acquires normal syntactic skills.