The discussion of this subject presupposes that in normal persons the stimuli perceived by the visuosensory center are transmitted to the visuopsychic areas, are there compared with previous visual pictures and are recognized as similar or dissimilar. There they are stored, but the manner in which they are stored is unknown.
Memory pictures stored in the visuopsychic center can be recalled to the field of consciousness either by the will or by stimuli coming from other cortical areas through the association tracts. Stimuli coming from without through the visual organs can also recall these memory pictures, and the flow of these stimuli is always from the visuosensory to the visuopsychic area. Never under normal conditions can the process be reversed. Stimuli from the visuopsychic or other cortical areas cannot stimulate the visuosensory areas. If this were not true, we could never be certain of the objective reality of our visual
H. H. HOPPE. A SYNDROME OF THE VISUOPSYCHIC CORTICAL AREA—BASED ON STABILE HALLUCINATIONS AND DEFECTIVE VISUAL ASSOCIATION IN A SANE PERSON. Arch NeurPsych. 1921;6(6):674–680. doi:10.1001/archneurpsyc.1921.02190060081007