Hierarchical Processing of Natural Scenes in the Human Pulvinar

The hierarchical organization of the ventral visual cortex has been the focus of theories and computational models characterizing high-level visual processing and object recognition, often overlooking potential contributions of subcortical structures. The pulvinar, through its extensive reciprocal connections with ventral visual cortex, is well-positioned to play a prominent role in high-level visual recognition processes. Here, we investigated whether the pulvinar plays such a role using a high-resolution 7T fMRI dataset of responses to tens of thousands of natural scenes. Encoding models testing the representation of different stimulus features revealed a pulvinar region selective for bodies and faces presented within the contralateral visual hemifield. Model-free analyses demonstrated that this region is predominantly co-active with body- and face-selective cortical areas during natural scene viewing. This functional specificity was embedded within a broader gradient of cortical correlations across the pulvinar mirroring the hierarchical organization of ventral visual cortex. These findings challenge cortico-centric models of object vision and implicate a role of the pulvinar in high-level vision. More broadly, these results demonstrate that principles of cortical organization, including functional clustering and hierarchical organization, also manifest in subcortex, and highlight the value of using naturalistic stimuli to probe visual function.