Parietal cortex and spatial cognition.

The parietal cortex consists of several prominent anatomical regions in the posterior part of the human brain. Although very heterogeneous stimuli and tasks activate parietal brain regions, a large body of empirical evidence points to a particular role of the posterior parietal cortex in spatial cognition. This article aims at providing a comprised overview regarding the existing evidence on the functional architecture of posterior parietal cortex and its relation to spatial cognition abilities. The article summarizes and systematically compares evidence from lesion, human functional brain imaging, and human functional brain interference studies, providing the whole range from early neuropsychological insights to latest state-of-the-art multimodal functional imaging and multivariate brain connectivity approaches. As for this latter type of evidence, the article outlines in more detail how our group has recently applied: (i) combined TMS & fMRI, (ii) data-driven multivariate fMRI, and (iii) effective brain connectivity analyses in order to functionally segregate the specific contribution of various parietal sub-regions for particular spatial sub-functions. Based on these recent findings, it is proposed that we are now at the verge of applying these new analytical frameworks in human functional brain imaging in order to functionally fractionate brain regions which are conventionally modelled as functional units, e.g. areas within the posterior parietal cortex, into distinct subdivisions with different functional contributions.