As for the reversibility of the mechanisms, this is not very clear; however the need for a vigilic level is. Here there is a synchronization between the ample degree of external perception (which progressively diminishes toward the level of sleep, wherein there is an increase of internal perception together with the imagination that is a transformer of impulses), with spontaneous and involuntary data from memory. Evocation is therefore only possible in vigil. It could be assumed that a datum, upon reaching its storage point, would trigger a remembrance at the same time it was recorded, which would explain automatic recognition (i.e., the sudden recognition of all the habitual objects through progressive conditioning). Finally, evocation would operate through “preferential pathways”—that is, through the pathways in which the track is progressively created.