Vision seems to be the most objective sense, purely reflecting the optical properties of the environment. However, as known from psychophysiological research, our perception can be fooled by optical illusions indicating the influence of cognition on perception. The neuronal underpinning of this process is still unknown. In this proposal, the functional neuroanatomy of visual areas will be studied at an unprecedented level of detail using ultra-high field fMRI. In particular, the subcortical visual brain areas will be investigated, which have been incorrectly but widely assumed to be just relay stations for passing visual information to the cortex for further processing.