Absence or inhibition of facial expressions, expressiveness of facial muscles, occurs in diseases of the nervous system and some mental diseases. A distinction is made between amemia, which occurs when the extrapyramidal system is affected and is associated with disorders of the motor components of emotional reactions (included in the syndrome of general akinesia) and amemia, which occurs when the frontal lobes of the brain are affected, associated with disorders of the emotional sphere (included in the frontal syndrome).