Map of spiking activity underlying change detection in the mouse visual system.

Visual behavior requires coordinated activity across hierarchically organized brain circuits. Understanding this complexity demands datasets that are both large-scale (sampling many areas) and dense (recording many neurons in each area). Here, we present a database of spiking activity across the mouse visual system-including the cortex, thalamus, and midbrain-while mice perform an image change detection task. Using Neuropixels probes, we record from >75,000 high-quality units in 54 mice, mapping area-, cortical-layer-, and cell-type-specific coding of sensory and motor information. Modulation by task engagement increased across the thalamocortical hierarchy but was strongest in the midbrain. Novel images recruited an expanded cortical population and modulated late cortical (but not thalamic) responses. Population decoding and optogenetics identified a critical time window for change detection and were consistent with mice using an adaptation-based rather than image-comparison strategy. This comprehensive resource provides a valuable substrate for understanding sensorimotor computations in neural networks.