Here, the fundamental question is the existence of a mental lexicon for pictures, as it exists one for words. And so, what is the structure of the semantic memory and its relationships with access modalities? In the first experiment we determine if a picture or a word can activate the same semantic structure by using the semantic priming paradigm. The classical effect of facilitation was found for word priming, but not for picture as prime. An hypothesis is that the semantic network activated by pictures is different from that activated by words. In the second experiment, we demonstrate that the semantic association structure for pictures and for words is different. So on the basis of these data, we replayed the experiment I. In this case, pictures as words could induce semantic priming of a word. And so we discuss the issue of multiple vs unitary semantic storage.