Sensory perception should not be regarded as one starting only (and solely) when the receptor is being stimulated. Along with the receptor component, the active component plays an essential role in the perception process. The main elements forming the active component are: expectation of a certain signal, prediction of the signal most probable in this particular situation, and an affective distinction determining the necessity of the signal for the individual perceiving the signal. Hence, a sequence of sensory phenomena can be formed (both for the normal and pathological states) depending on the relation between the receptor and active components.