VISUAL RESPONSES IN DIFFERENT SPATIAL AND GLOBAL CONTEXTS IN MOUSE PRIMARY VISUAL CORTEX

While primary visual cortex (V1) has traditionally been viewed as a visual feature detector, recent work shows V1 can additionally be modulated by spatial position – responding differently to visually identical landmarks present in different spatial positions within a virtual reality room. However, it remains unclear if V1 responses modulated by spatial position are also modulated by the global context, for instance when cues are in distinct virtual rooms. We investigated this using simultaneous Neuropixels recordings in V1 and medial entorhinal cortex (MEC) while mice navigated two virtual tracks. Crucially, both tracks contained the same visual landmark at two matching positions, creating a hierarchical design (2 positions in 2 tracks) that allowed us to disentangle the influence of spatial position and track identity. We analysed the activity both at single-neuron and population (using factor analysis) levels. We found that in addition to spatial modulation, track identity also influenced V1 activity, both at single-neuron and population levels. At a single-neuron level, 36% of V1 neurons were significantly influenced by position, 26% by track identity, and 6% showed significant interaction effects between the two. At a population level, V1 neural trajectories of identical landmarks from different position and track identity did not overlap. The differentiation between the two tracks was present in both the population representation in MEC (which showed remapping between the two tracks) and animal behaviour. These findings demonstrate that V1 generates unique representations for identical visual inputs, resolving sensory ambiguity in both spatial position and global context.