摘要：Speaking fluently requires successful inhibition of the past, selection of the present, and priming of the future.We suggest that executive abilities undergird fluency by mediating these functions. To test this, we compared taskswitching abilities of three patients with left-hemisphere lesions, who were matched on their comprehension andsingle-word production abilities, but differed in their fluency levels, to a control group. A task-switching paradigmwas chosen because it captures the three functions mentioned above, that we take to be necessary for producingfluent speech. The pattern of results, including contrasting error patterns of the two non-fluent patients, supports ourhypothesis and argues for a two-level model of conflict-resolution.
