The article analyzes the mechanisms of phraseological units formation and imprinting in the language. Structural features of a phraseological unit are explored through the specifics of human thinking in the world cognition. Nonverbal components accompanying a phraseological unit in the origination and in the further use in speech are revealed. To identify the mechanisms of phraseological units formation the pathological deviations from normal heterogeneous work of hemispheres are studied. Perception of metaphors and phraseological units by people with divided consciousness – patients with schizophrenia is taken as an example.