Grant: Operating Grant

The association cortex of the human brain, which is involved in the highest aspects of cognition, comprises several areas that exhibit differences in their cellular structure (i.e. cytoarchitecture). In recent years, developments in functional neuroimaging with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have made it possible to demonstrate distinct changes in neuronal activity within the human brain in relation to specific aspects of cognitive processing. A proper interpretation of these activation foci requires their integration with what is known about the anatomy and physiology of the primate cortex, i.e. information that has been gathered almost exclusively in experimental work in the monkey. Unfortunately, for many regions of the cortex, the architecture in the monkey and the human brains were not studied in parallel and with the same criteria. There are therefore several inconsistencies in the organizational schemes of the monkey and the human cortex that prevent the effective utilization of basic knowledge about anatomy and physiology to interpret findings from functional neuroimaging studies in human subjects. The present grant proposes a research program to resolve some of the above problems. The research plan involves a comparative examination of human and macaque monkey brains stained for cytoarchitecture in order to define areas in the regions of interest according to the same criteria in these two primate species and then examine whether the areas defined relate to particular sulci of the human brain. The studies should provide a solid basis on which to interpret human functional activation studies.