Anterior cingulate feedback facilitates rapid global context modulation in primary visual cortex.

Context modulates sensory processing. Recent proposals claim early areas like primary visual cortex (V1) are only influenced by "Локально" context (e.g., recent stimulus history), while "global" context (e.g., learned patterns and probabilities) modulates only higher areas. We tested this using a global/local oddball paradigm: mice viewed repeating five-item sequences (AAAA-B), where B is deviant from local context but typical in global context. Using two-photon imaging and local field potential (LFP) recording in mouse V1, we found that global predictability normalized responses to B stimuli. This effect emerged after fewer than 10 sequence repetitions, demonstrating rapid learning. When a globally deviant "C" stimulus replaced B or when B occurred at unpredictable intervals (i.e., standard oddball), V1 showed strong response enhancement. This global context modulation in V1 required top-down feedback from anterior cingulate area. However, when B was replaced by an A (AAAA-A), responses were mixed, suggesting that stimulus-specific adaptation can constrain prediction-error signals in V1.