Postdictive Perception in Primary Visual Cortex

The Science of Postdiction

Do brain representations reflect what was presented to our eyes (retinal input) or what we actually perceive? This project investigates Postdiction, a phenomenon where information arriving later influences how we perceive an earlier event.

Research Highlights & Technical Achievements

• Advanced Neuroimaging: Used 7T fMRI to achieve layer-specific resolution in the primary visual cortex (V1).
• Layer-Specific Decoding: Discovered that deep layers of V1 encode subjective perception (illusory flashes), while middle layers continue to track the objective retinal input.
• Top-Down Modulation: Identified that postdictive perception is likely facilitated by feedback from superior temporal cortex to the early visual cortex.
• Project Management: Led a £400K project end-to-end, managing a team of three students and coordinating data collection for over 300 participants.
• High-Impact Communication: Presented findings at the Visual Science Society (VSS) 2025.

Scientific Impact

Our findings complete a feedback model of sensory processing across seeing and hearing, suggesting that early visual cortex is not just a passive relay station but an active participant in constructing hallucinations and perception.