A causal role of the NMDA receptor in recurrent processing during perceptual integration.
eLife June 18, 2025 Samuel Noorman, Timo Stein, Jasper Zantvoord et al. 2 citations
Perceptual inference—how the brain integrates visual features into a coherent whole—depends on recurrent processing, the back-and-forth communication between higher and lower cortical regions. Animal studies have implicated NMDA receptors in this process, but human evidence was lacking. In two double-blind, placebo-controlled experiments with healthy participants, the NMDA receptor antagonist memantine selectively improved the brain's ability to decode complex visual illusions (Kanizsa triangles) that require recurrent processing, while leaving simpler visual processing (contrast and collinearity) unaffected. This enhancement occurred only when stimuli were attended and consciously perceived. The findings suggest that blocking NMDA receptors can enhance recurrent processing for attended objects, linking animal and human research on the neural basis of conscious perception.