Reward coding across mouse visual cortical areas

The visual cortex is an established site of reward-related signaling, but this evidence comes almost entirely from the primary visual cortex and from trained associative paradigms, leaving open whether and how a dedicated reward signal is organized across the visual cortical hierarchy as a whole. Here we show, using 103 sessions of the Allen Visual Behavior Neuropixels dataset in which head-fixed mice performed a visual change-detection task, that reward is encoded throughout the mouse visual cortex. Aligning the activity of 54,039 units to reward delivery, we identified reproducible peri-reward responses with a split-half test against an inter-spike-interval null, and retained only units whose modulation was reward-specific across two contrasts: active behavior vs. passive replay, and hit vs. miss. A substantial cohort of units, distributed across all six visual areas, was reward-modulated. This modulation was dominated by suppression, whose predominance decreased systematically along the functional hierarchy, from the primary visual cortex towards higher-order areas, and was concentrated in layer 4 and in narrow-spiking neurons. At the population level, the reward-modulated cohort operated in a lower-variability regime than the surrounding population in every area. Decomposing the peri-reward responses showed that they do not fall into discrete types but form a shared continuum of temporal profiles, common across areas, within which an anticipatory ramp preceding reward was most prevalent in the primary visual cortex. These findings indicate that the mouse visual cortex carries a distributed, predominantly suppressive and anticipatory reward signal, hierarchically graded yet built from a shared temporal repertoire.