Human pulvinar functional organization and connectivity

The human pulvinar is the largest thalamic area in terms of size and cortical connectivity. Although much is known about regional pulvinar structural anatomy, relatively little is known about pulvinar functional anatomy in humans. Cooccurrence of experimentally induced brain activity is a traditional metric used to establish interregional brain connectivity and forms the foundation of functional neuroimaging connectivity analyses. Because functional neuroimaging studies report task-related coactivations within a standardized space, meta-analysis of many whole-brain studies can define the brain's interregional coactivation across many tasks. Such an analysis can also detect and define variations in functional coactivations within a particular region. Here we use coactivation profiles reported in ~ 7,700 functional neuroimaging studies to parcellate and define the pulvinar's functional anatomy. Parcellation of the pulvinar's coactivation profile identified five clusters per pulvinar of distinct functional coactivation. These clusters showed a high degree of symmetry across hemispheres and correspondence with the human pulvinar's cytoarchitecture. We investigated the functional coactivation profiles of each resultant pulvinar cluster with meta-analytic methods. By referencing existent neuroimaging and lesion-deficit literature, these profiles make a case for regional pulvinar specialization within the larger human attention-controlling network. Reference to this literature also informs specific hypotheses that can be tested in subsequent studies in healthy and clinical populations.