In some states, including dreaming, the illusion is separate from the self and the person does not perceive that he or she is imagining things. Illusions” are created by taking information from sensory memory and piecing it together and sending it back to the sensory area. The purpose of hallucinations is to replace real signals with simulated sensory signals to drive the autonomic nerves for psychosomatic action. What are the main aspects of the diagnosis of hallucinations? 1. True hallucination: The spontaneous excitation of the cortical receptor areas of the brain makes the past image active and reappear, which is the appearance. Because the appearance is particularly strong, sharp, vivid, detailed and “”projection”” to the external objective world.”” Projection”” means that when the intensity of the activation of the appearance is so great that it is the same as the reflection of the real stimulus, it is impossible to distinguish it from the reflection of the real stimulus in the human consciousness, but it is assumed that it comes from the objective space according to the conventions of life, so it is a natural process of outward projection. 2, pseudo hallucination: if the reappearance of the image traces only to the extent of the equivalent of the surface, less sharp, vivid, detailed, only active in the mind, not to the objective world “”projection””, and is a small random and generated, then it is a pseudo hallucination. 3, residual hallucinations: a longer duration, no close relationship with mood hallucinations, often seen in patients with schizophrenia. Patients have a dreamy feeling, as if they were dreaming of a strange sensation, often in conjunction with hallucinations. A feeling that is proven to be unreal by objective tests because of the lack of corresponding realistic stimuli, but does not feel unreal as far as the patient’s own experience is concerned. Some patients are convinced that the sensations come from objective reality.