Neurons of different brain regions change their response when a stimulus is repeated. In macaque inferior temporal cortex (IT), stimulus repetition typically reduces the responses of single neurons, i.e. show repetition suppression. I will discuss the contribution of various mechanisms, including the role of expectation, that have been proposed to explain repetition suppression, reviewing published and novel single unit recording data obtained in awake monkey IT. Together, our data agree with the hypothesis that adaptation in IT serves to reduce the saliency of recently seen stimuli, highlighting stimuli that differ from recently presented ones.