Abstract: In this study we investigate temporal slowness as a learning principle for receptive fields using slow feature analysis on image sequences. We analyze the results with physiological methods and compare them to neurons reported in the experimental literature. We find that the learned functions have many properties found also experimentally in complex cells of primary visual cortex, such as direction selectivity, non-orthogonal inhibition, end-inhibition, and side-inhibition. Our results demonstrate that a single unsupervised learning principle can account for such a rich repertoire of receptive field properties.