In the brain of the beholder: bi-stable motion reveals mesoscopic-scale feedback modulation in V1
Brain Structure and Function April 5, 2025 Alessandra Pizzuti, Omer Faruk Gulban, Laurentius Renzo Huber et al.
During a bistable visual illusion where motion perception alternates despite constant input, the primary visual area (V1) and the motion-sensitive area hMT+ show distinct patterns of activity. Using high-resolution 7 Tesla fMRI, researchers found that hMT+ activity correlates with conscious perception equally for both ambiguous and physical motion stimuli, with no difference in its laminar profiles. In contrast, V1 shows reduced functional response to ambiguous stimuli, reflecting feedback signals rather than feedforward input, and its laminar profiles differ between conditions. Temporal coupling between V1 and hMT+ increases during ambiguous perception, suggesting feedback from hMT+ to V1 helps stabilize the vivid perception of directed motion.