According to the structure of any analyzer system (peripheral part of the analyzer, primary and secondary cortical fields), two types of disorders are distinguished:
1) Sensory disorders are relatively elementary, reflecting a violation of various types of sensations (light perception, color perception, sensation of pitch, volume, duration of sound, etc.).
2) Gnostic disorders are more complex, reflecting disorders of various types of perception (perception of the shape of an object, symbols, spatial relations, speech sounds, etc.). Gnostic disorders that occur with cortical lesions are called agnosias. Depending on the affected analyzer, auditory, visual and sensory agnosias are distinguished, each of which includes a large number of forms of disorders.