Discussing Marian apparitions in the light of current knowledge in neuroscience is a challenge: the testimonies are often old and indirect, and the “visionaries” could not be questioned or even examined according to current neurological or psychiatric standards. In doing so, we are not unaware of the heterogeneity of seers and the facts they reported: there is not necessarily a single hypothesis. It is the appearances of Île Bouchard that will be discussed here. Our interpretation calls on two non-exclusive “mechanisms”: on the one hand, mental imagery, which we know can be unconscious and is modulated or generated by frontal “top-down” mechanisms; on the other hand, the sociological consideration of events, using the concept of enchantment.