He was the first to name reduplicative paramnesia. It often occurs in conjunction with a reduplicative vowel suffix. Most words are created by either compounding or reduplicative derivation. "Faithfulness and reduplicative identity". In reduplicative hallucinations there is the perception of seeing a double. Compulsive behaviours, stereotypies and reduplicative paramnesias can be part of the CNS spectrum. Particular kinds of reduplicative hallucination include autoscopy, heautoscopy and out-of-body experiences. During the typical reduplicative babbling stage, the vocal activity of deaf children decreases dramatically. One can further categorize the reduplicative words into "True" and "Quasi" ones.