Contextual and Predictive Coding in V1

Primary visual cortex (V1) is often characterized by the receptive field properties of its feed-forward input (only up to 5%). We focussed our fMRI studies on nonstimulated retinotopic regions in V1 to gain a better understanding of contextual processing. We investigated activation along the nonstimulated long-range apparent motion path (1), occluded a visual quarterfield of a natural visual scene (2), or blindfolded our subjects and presented environmental sounds (3). We were able to demonstrate predictive activity along the illusory apparent motion path (1), use decoding to classify natural scenes from nonstimulated regions in V1 (2), and to decode environmental sounds from V1, V2 and V3 (3). Is this contextual processing useful to predict upcoming visual events? To investigate predictability we used apparent motion as the prime stimuli and tested with a probe stimulus along the apparent motion path to find that predicted stimuli are processed more efficiently—leading to less fMRI signal and better detectability (1). In summary, we have found brain imaging evidence consistent with the hypothesis of predictive coding in early visual areas.