Cognitive risk-taking after frontal or temporal lobectomy--II. The synthesis of phonemic and semantic information.

Patients with unilateral cerebral excisions and control subjects performed two tasks in which target words had to be guessed on the basis of either phonemic or semantic partial-information clues. Each cumulatively provided clue was assigned successively lower point-value, these points being risked whenever the subject responded. Patients with frontal-lobe excisions chose to make a guess after seeing only one clue more often than did a combined group of subjects without frontal-lobe damage, but this guessing-score was also related to extent of right temporal-lobe removal. Patients with left temporal-lobe or left frontal-lobe lesions had difficulty solving the verbal clues, occasionally failing to recognize that a response generated in the context of one clue satisfied all the clues.