Complementary role of frontal theta and parietal alpha activity in resolving visual competition
Attention plays a central role in selecting information for conscious perception. Because natural environments are structured, prior knowledge about relevant and irrelevant features can guide this selection. However, prior knowledge about distractors can enhance their neural representation, raising the question of how the brain prevents such enhancement from interfering with behavior. We addressed this question by combining a binocular rivalry paradigm with frequency-tagged stimuli to independently track target and distractor signals during sustained perceptual competition. We identified a sequential pattern of oscillatory dynamics underlying stable perception. Early parietal alpha activity (8-12 Hz) was associated with the segregation of competing inputs without altering sensory gain. This was followed by frontal theta activity (3-7 Hz), which was linked to the reactive suppression of distractors representations. Importantly, alpha-mediated gating effects are most pronounced under high perceptual uncertainty, where they facilitated the stabilization of weak target signals and promoted their access to conscious awareness. Together, these findings demonstrate that perceptual competition is resolved through a coordinated sequence of proactive gating and reactive suppression.