Natural speech reveals the semantic maps that tile human cerebral cortex | The Gallant Lab @ UCB

The meaning of language is represented in regions of the cerebral cortex known collectively as the “semantic system”. However, little of the semantic system has been mapped comprehensively, and the semantic selectivity of most regions is still unknown. Here we systematically map semantic selectivity across the cerebral cortex using voxel-wise modeling of fMRI data collected while subjects listened to several hours of natural narrative stories. We show that the semantic system is organized into intricate patterns that appear highly consistent across individuals. We then use a novel Bayesian generative model to map these patterns and create a detailed semantic atlas. Our results suggest that most areas within the semantic system represent information about specific semantic domains and our atlas shows which domains are represented in each area.