6 – Mapping Prefrontal Cortical Systems for the Control of Cognition

Publisher Summary This chapter focuses on the contribution of functional neuroimaging studies with positron emission tomography and functional magnetic resonance imaging to understand the functional organization of the lateral prefrontal cortex. The analysis of the effects of middorsolateral prefrontal lesions on memory established two important facts that define the specialized functional contribution of this region. First, the demonstration that middorsolateral prefrontal lesions impair performance on nonspatial visual working memory tasks, with the appropriate monitoring requirements, indicated that this region cannot simply be conceived as a specialized working memory module for spatial information. Second, it is clear that, following middorsolateral prefrontal cortical lesions, information can still be maintained on-line but that the capacity to consider multiple pieces of information in working memory is severely reduced. Based on this analysis and other anatomical and behavioral work, it was proposed that the middorsolateral and the midventrolateral prefrontal cortex underlie two distinct levels of executive control of cognition. This theoretical model proposed that the middorsolateral prefrontal cortex is a specialized region for the on-line monitoring and manipulation of cognitive representations within working memory.