Neurolinguistic analysis of verbal utterances in patients with focal lesions of frontal lobes

Verbal utterances of 105 patients have been analyzed. Six groups of subjects were examined including patients with left dorsolateral frontal lesions, left orbitofrontal lesions, right frontal lobe lesions, posterior aphasics, posterior brain-damaged patients without aphasia, and a matched control group. Results indicate that the left frontal lobe is involved in organization of linguistic information. Its dorsolateral part seems to be concerned with forming the sequential pattern of an utterance, and the orbital part with the directed development of a narrative. It is conceivable that the right frontal lobe is important for the global, nonlinguistic organization of information to be uttered.