Binocular rivalry

In a controlled display, one eye can receive horizontal stripes while the other receives vertical stripes. Perception may switch between the patterns even though the display stays fixed; sometimes parts of both are seen. How do the brain’s competing signals and their interactions over time produce these switches?[1] [2]

When the eyes receive incompatible patterns, perception can alternate while the inputs remain unchanged. How do eye-specific competition, pattern competition and feedback organize those changes? In models, interacting groups of nerve cells suppress each other; a weakening response during sustained activity and random variation can contribute to switches. Functional MRI, or fMRI, measures activity-related changes in blood oxygenation. A 2025 study found eye-related activity patterns consistent with local competition in V1, the primary visual cortex, and feedback involving a parietal region. The study focused on eye-specific signals; it did not fully test the competition between represented patterns.[1] [2]

Some eye-specific circuits are known. Their interaction with pattern competition and timing remains incomplete.[1] [2]

The 2025 mesoscale imaging study establishes important eye-specific constraints, while fMRI temporal limits and interaction with pattern competition leave the full switching mechanism incomplete.[1]

The external patterns can stay constant while what you see changes. That makes rivalry a useful way to separate the sensory input from the brain processes shaping a particular visual experience.[1] [2]

Rivalry offers a controlled difference between what is presented and what is perceived. Tracking local conflicts as they spread across a display connects neural dynamics to the coherence of visual experience, without treating one laboratory illusion as a complete explanation of consciousness.[1] [2]