Several mechanisms of perceptual and cognitive relevance which are often activated during artistic fruition are illustrated. These are phenomena of ambiguity, incongruity and masking, largely clarified in their dynamics by perception and thinking psychology researchers. The connections between these phenomena and the psychoanalytic concepts of ambivalence, conflict and repression are indicated. It is claimed that appropriate consideration of these psychological references contributes to enrich complex communications comprehension, such as in the case of artistic languages. Through analyses carried out on renaissance and contemporary works of art, it is shown how the use of the meanings suggested by the above mentioned perceptual phenomena allows to highlight latent contents.