Sensory physiology is the branch of physiology that studies how a sensory stimulus is transduced by sensory receptors and processed by the nervous system. As a discipline, sensory physiology is based on the experimental measuring of physical parameters (such as voltage or pressure) both as input and output of the sensory systems, and is complemented in its study of sensory perception by psychophysics, which instead focuses on the relationship between the physical characteristics of a stimulus (directly measurable) and the attributes of the sensory experience (obtained by introspection of the subject).
During the 19th century, researchers of the German school of Physiology (such as Ernst Weber, Gustav Fechner, Hermann Helmholtz, and Wilhelm Wundt) laid the foundations for both sensory physiology and psychophysics.
In particular, they found:
-that sensory perception always involves three common steps: 1- a physical stimulus, 2- a set of events translating the stimulus into a pattern of nerve impulses, and 3- perception or conscious experience of sensation.
-that all sensory systems convey four basic types of information about the stimulus when stimulated: modality, location, intensity, and timing.