Lexical-semantic deficits following right hemisphere damage: evidence from verbal fluency tasks.

The evidence of lexical-semantic deficits following right, non-language-dominant hemisphere injury was assessed using word (or verbal) fluency tests. Two groups of subjects (non-brain-damaged controls and right hemisphere-damaged patients) were indistinguishable in their performances on convergent lexical tasks. Subjects completed verbal fluency tasks by five semantic criteria. The brain-damaged subjects produced significantly fewer responses on two of the categories and demonstrated fewer lexical retrieval strategies. The results were interpreted as evidence that lexical-semantic knowledge is largely intact following right-hemisphere damage, and that apparent lexical deficits result from failure to use lexical knowledge flexibility, suggesting that right-hemisphere language disorders may stem from broader cognitive failures.