“The enabling power of 7T for cognitive neuroscience: the case of numerosity”
Dr. Serge O. Dumoulin
Director, Spinoza Centre for Neuroimaging
Date/Time
Monday, October 31 2022, 9:30-10:20
Abstract
Ultra-high field MRI at 7 Tesla (7T) stands to revolutionize cognitive neuroscience due to its greatly increased sensitivity and specificity. One popular avenue of research is to let the improvements in sensitivity go towards higher spatial resolutions to reveal the fundamental computations performed within a given cortical area, ultimately allowing the visualization of the mesoscopic organization of the human brain. However, a much more readily available and more powerful gain for cognitive neuroscience are whole-brain fMRI experiments of the type that are now customarily conducted at a field strength of 3 Tesla. Specifically, when spatial resolution is optimized to sample gray matter, i.e. gray-matter optimized fMRI, this brings the information-processing characteristics of local neuronal populations in the living human brain into clear view. I will highlight these advantages of 7T MRI in the field of numerical cognition, specifically neural mechanisms of numerosity, i.e. the set size of a group of items. Using 7T MRI and population receptive field modelling, we described neural populations responding to specific numerosities organized in systematic topographic maps, analogous to primary sensory and motor cortical maps. These numerosity maps extend topographic principles to higher-order features in association cortex. I will also show why the reconstruction of these maps, and cognitive neuroscience in general, needs 7T MRI.