Provide a running comentary on the patient's actions

Hallucinations are defined as false perceptions in the absence of a real external stimulus. They are perceived as having the same quality as real perceptions and are not usually subject to conscious manipulation.
Hallucinations in schizophrenia may involve any of the sensory modalities. The most common are auditory hallucinations in the form of voices (...). Although voices in the second person are most common, the characteristic "Schneiderian" voices are in the third person and provide a running comentary on the patient's actions, arguing about the patient or repeating the patient's thoughts. Voices may be imperative, ordering the patient to harm himself or others. (...)

in An Atlas of Schizophrenia