Brain processes predicting future perception: cortical feedback and visual predictions

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Brain processes predicting future perception: cortical feedback and visual predictions We investigate cortical processing strategies using functional brain imaging. Previous evidence has shown that early visual areas receive feedback from higher visual areas. We have shown previously that this feedback activity helps to predict future perception. In three functional magnetic resonance imaging (fMRI) experiments we will test feedback and prediction with natural visual scenes (experiment 1 and 2) or with natural viewing conditions (experiment 3). To extract meaning the brain has to set incoming sensory information into the context of previous and future events. From moment to moment the visual system needs to decide what is present in its environment and how to interact with it. Perception 'postdicts' events if they occur unforeseen, that is perception is a reconstruction of the recent past, if upcoming events are however predictable the visual system incorporates this knowledge in the perceptual processing. Little is known about the brain processes underlying this predictive coding. One of today's biggest scientific challenges is the identification of important cortical processing principles. Tentative models that try to identify the essential principles are relatively rare. Feedback and prediction play an important role in some recent theories about brain processing. The memory-prediction framework of intelligence has been a relatively recent approach to isolate essential processing strategies. In this theory, the main tasks of cortical modules are to extract a plausible categorisation that helps to predict future events. Cortical areas integrate upcoming and neighbouring information and forward the current interpretation to higher areas and at the same time back-project the results to lower tier areas. Lower cortical areas compare the upcoming information with the prediction of higher cortical areas and generate a new pattern or error signal if the prediction was incorrect. The memory prediction framework assumes that the processing principles are quite general and apply to all cortical areas including primary sensory areas. Some evidence in favour of feedback and prediction has used artificial / easy to predict / stimuli. Here we will test in primary visual cortex (area V1) whether complex predictions can be formed with natural visual scenes. Two experiments will use complex visual stimuli taken from 3D-movies to initiate complex expectations. Subsequently the predictions will be tested using a newly developed fMRI-anticipation design. The third experiment will test visual predictions in the context of eye-movements.