Exteroception

Exteroception 

the perception of environmental stimuli acting on the body. The stimuli are perceived by special, sometimes highly complex, structures called exteroceptors. An example of exteroception is the perception of light, sound, or heat.

The various external stimuli that excite the exteroceptors determine the volume of information needed by a living organism to adapt properly to the environment. They are also responsible for the nature of conditioned and unconditioned activity. The types of exteroceptors most important for a particular organism developed in the course of evolution. For example, fishes developed a lateral line, which perceives the hydrodynamic properties of water, and bats acquired an apparatus for locating ultrashort sound waves. Conditioned reflexes are essential for perceiving external objects. For example, a combination of stimuli emanating from the retina and eye muscles and coinciding several times with tactile stimuli from an object becomes a conditioned signal of the size of the object.

V. N. CHERNIGOVSKII