The pulvinar nuclei as a computational system: Computing and calibrating the organization of 3-D visual space

Project in DFG Priority Program SPP2411
We present a novel hypothesis of the functions of the pulvinar in the primate and make proposals for specific tests to probe predictions of this hypothesis. The pulvinar nuclei are greatly enlarged in primates compared with other mammals. We advance the view that the pulvinar may function as a computational system that is specifically suited to adaptive computation. As a specific case of this general hypothesis, we will examine how the pulvinar and its connected neocortical areas may support the structuring of 3-D spatial relationships in the visual world. Information about the 3-D structure of the immediately visible world is important for both sensory, perceptual judgments about the size, shape and position or objects, but also for motor activity, particular the control of eye movements. In humans, such movements are inherently binocular in nature and therefore embedded in 3-D spatial processing. Few, if any, studies of the pulvinar nuclei have examined binocular 3-D properties of pulvinar neurons. By contrast, there has been extensive study of the binocular function of sensory cortical areas. We seek to build upon the current canonical view that the pulvinar nuclei provide a relay or ‘efference copy’ of cognitive signals such as spatial attention. This project will test the hypothesis that the pulvinar relay applies a transform to neuronal signals about 3-D spatial relationships as they pass from one visual cortical area to another. We will make dual electrophysiological recordings from the pulvinar nuclei and anatomically connected visual cortical areas The project will test the adaptive, regulatory role of the pulvinar by employing standard visuomotor adaptation paradigms, in combination with interventions that aim to temporarily and reversibly disrupt pulvinar function.