How the brain integrates affective and propositional language into a unified behavioral function. Hypothesis based on clinicoanatomic evidence.

Recent publications suggest that the right hemisphere dominates in modulating the affective components of language. Disorders of language form right-sided focal brain lesions have been called "aprosodias" and can be classified in a manner similar to the aphasias. We describe a patient with motor aprosodia who subsequently died and underwent neuropathologic examination. From the neuropathologic findings and recent observations concerning the neurology of depression, we hypothesize that the motor integration of propositional and affective language takes place in the brainstem, whereas their higher-order integration takes place via the callosal connections between Wernicke's area on the left and its homologue on the right. Direct application of these functional and anatomic relations can help clinicians to properly interpret the often incongruous and disparate behavioral and language responses encountered in brain-damaged patients.