Cortical predictions in everyday life
The brain is not a passive receiver of sensory information. Rather, our brains guide us through the world, foretelling the sensory stimulation they will receive moment-by-moment. As we begin our day at work, we know the force with which to turn the office door handle, where the computer will be positioned on the desk, and which colleagues will greet us with a smile. Evidence from action, perception and social cognition reveals that the brain uses contextual expectations based on internal models to achieve this. Our research uses functional magnetic imaging of primary visual cortex V1 to investigate the brain’s prediction of the environment in perception.
The hypothesis for brain imaging – feedback and top-down processing
The cortex has more “backward” projections than it does “forward”, which fits well to early hypotheses that the brain uses memory and expectation to form predictions of input. Our lab has established a way to measure the role of feedback in prediction, using functional magnetic resonance imaging combined with retinotopic mapping to identify regions of V1 receiving no sensory stimulation (and therefore only feedback/lateral input). We use multivariate pattern classification to decode the information content of these top-down signals. We are now extending this methodology to high resolution laminar analysis using 7Tesla imaging in collaboration with Maastricht Brain Imaging Center (MBIC).