BRAIN FUNCTIONAL PROFILES IN FORMAL AND SEMANTIC FLUENCY TASKS - A SPECT STUDY IN NORMALS

SPECT method is used to analyze changes in regional cerebral blood flo w in a group of 19 normal subjects during a baseline task (repetition of two words) and two verbal fluency tasks, a semantic fluency and a f ormal fluency. The semantic fluency task was associated with a relativ e CBF increase in the right dorso-lateral and medial frontal region wh en compared with that seen in the baseline condition. No specific acti vation was found for the formal fluency task compared to that seen in the baseline task. We suggest that the activation of the right frontal region reflects semantic categorization strategies in semantic fluenc y. The lack of activation of the left frontal region may be due to an activation induced by the nature of the baseline task (i.e., a self-pa ced repetition task). (C) 1996 Academic Press, Inc.