Seminar Series

Seeing is believing - How priors shape perception

Perception is not simply a passive process of accumulation of sensory evidence, but it is strongly shaped by internal brain states, which incorporate our goals, attention, expectations, and knowledge about the world. In my talk, I will focus on how expectation shapes perception. Does it “change the evidence” or “change the weight of the evidence”? I will discuss recent neuroimaging data (MEG and fMRI) and multivariate methods (MVPA) that show how expectation reduces neural activity in early sensory cortex, yet boosts the amount of information that can be “read out” from these areas. In conclusion, I will argue that priors in the brain both “change” and “weight” sensory evidence during perceptual decision-making. References: * Kok P, Jehee JFM, de Lange FP (2012). Less is more: Expectation sharpens representations in the primary visual cortex. Neuron 75, 265-270. pdf * de Lange FP, Rahnev D, Donner TH, Lau HC (2013). Pre-stimulus oscillatory activity over motor cortex reflects perceptual expectations. Journal of Neuroscience, 33, 1400-10. pdf