Abstract
Primary visual cortex (V1) is often characterized by the receptive field properties of its feed-forward input. Direct thalamo-fugal input to any V1 cell however, is less than 5% (Douglas and Martin, 2007), and much of V1 response variance remains unexplained. We propose that one of the core functions of cortical processing is to predict upcoming events based on contextual processing. To gain a better understanding of contextual processing in the cortex we focused our fMRI studies on non-stimulated retinotopic regions of early visual cortex (2). We investigated activation along the non-stimulated long-range apparent motion path (1), occluded a visual quarterfield of a natural visual scene (3), or blindfolded our subjects and presented environmental sounds (4). We were able to demonstrate predictive activity along the illusory apparent motion path (1), use decoding to classify natural scenes from non-stimulated regions in V1 (3), and to decode environmental sounds from V2 and V3, but not from V1 (4). Is this contextual processing useful to predict upcoming visual events? To investigate predictability we used our contextual stimuli (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 that is consistent with the hypothesis of predictive coding in early visual areas.