Control of representation updating by higher-order thalamus enables history-based decision-making

When sensory information is ambiguous, we must interpret current inputs based on a representation constructed from our previous experiences. Although appropriately updating this internal representation to track environmental changes is essential for behavior, the neural basis of this dynamic integration remains unknown. Using a combination of multi-area single-unit recordings and optogenetic techniques in mice under both behavioral and passive conditions, we find that interactions between the posterior parietal cortex (PPC) and its higher-order thalamic counterpart, the pulvinar (PUL), are necessary to stably maintain representations underlying decision-making based on sensory history. We also identify a mechanism by which shifts in statistical patterns across recent sensory experiences engage inhibitory control of the PUL by the thalamic reticular nucleus (TRN) to facilitate the updating of encoded sensory history. Our results establish a framework in which complementary operations in the thalamus and cortex act in concert to allow internal representations to adaptively track changing conditions.