A thalamocortical circuit encoding deviations from sensory history

Prior expectations guide attention and support perceptual filtering during decision-making. In mice performing a visual discrimination task, choices depended on trial-by-trial differences between consecutive stimuli (|ΔDir|). We hypothesized that thalamic lateral posterior (LP; rodent pulvinar) projections to prefrontal areas such as the anterior cingulate cortex (ACC), previously implicated in selective attention and predictive processing, could support history-dependent evaluation of current sensory evidence. In this work, we report that optogenetic manipulations of LP-ACC axons disrupted history-dependent evaluation of current sensory evidence, producing |ΔDir|-dependent choice biases. Two-photon imaging showed that LP-ACC axons represented stimuli along a task-dependent low-dimensional curved manifold whose geometry scaled with |ΔDir|, emphasizing larger deviations from recent evidence. These findings identify the LP-ACC as a thalamocortical pathway that implements a contrastive, history-referenced representation of sensory evidence during decisions.