Cerebral regions associated with verbal response initiation, suppression and strategy use

Cerebral activation associated with performance on a novel task involving t wo conditions was investigated with functional magnetic resonance imaging ( fMRI), In the response initiation condition, subjects nominated the general subordinate category to which each of a series of exemplars (concrete noun s) belonged. In the response suppression condition, subjects were required to nominate a general superordinate category Co which each exemplar did not belong, with the instruction that they a ere not to nominate the same cate gory response twice in a row. Both conditions produced distinct patterns of activation relative to an articulation control condition employing identic al stimuli. When initiation and suppression conditions were directly compar ed, response suppression produced activation in the right frontal pole, orb ital frontal cortex and anterior cingulate, left dorsolateral prefrontal co rtex and posterior cingulate, and bilaterally in the precuneus, visual asso ciation cortex and cerebellum Response latencies were significantly longer in the suppression condition. Two broadly-defined strategies associated wit h the comet production of words during the suppression condition were a sel f-ordered selection from among the superordinate categories identified duri ng the first section of the task and the generation of novel category respo nses. The neuroanatomical correlates of response initiation, suppression an d strategy use are discussed, as are the respective roles of response suppr ession and strategy generation. (C) 2000 Elsevier Science Ltd. All rights r eserved.