APA Dictionary of Psychology

n. in schizophrenia, the transformation of abstract concepts into specific perceptions. For example, an individual who thinks poorly of themself may later experience hallucinations that bad odors are emanating from their body; the rotten personality becomes the rotten body that smells. Perceptualization is the most advanced level of active concretization. [defined by Italian-born U.S. psychiatrist Silvano Arieti (1914–1982)]