With respect to mechanisms underlying paramnesias, Kraepelin was less clear. He mentioned 'alterations of consciousness' which occurred with varying severity and caused a reduced capacity to differentiate between reality and fantasy. During the nineteenth century, the generic term paramnesia was used to refer to a group of clinical phenomena amongst which déjà vu, confabulations, and delusions and hallucinations of memory remain the more salient. These phenomena had been known since earlier but it was only after the work of Sander that they began to be considered as 'memory' disorders. In Kraepelin's taxonomy the paramnesias are included as 'qualitative' disorders of memory affecting either recognition or recollection. Déjà vu remains a curiosity seen in some forms of epilepsy and occasionally in the normal affected by fatigue. Delusions of memory are occasionally mentioned in the literature but hallucinations of memory have disappeared altogether.