The external, visible parts of our sense organs are usually a focusing device, that functions much like a satellite dish. The funnel shape of the ear focuses the mechanical vibrations of sound into the inner ear and the cochlea. The nose, as we inhale, pulls chemicals from the air onto the olfactory epithelium. The information contained in the original stimulus has become a neuronal code. It is no longer in its original form.
Nature tends to repeat and remodel a good design.
Nerve Pathways Way Stations . Once the energy from the outside world becomes translated into neuronal energy, it is coded according to important attributes, and is sent to an ultimate destination in the cerebral cortex. The thalamus is like a huge switching station, which properly routes incoming sensory information. Fortunately, extensive damage to the thalamus is rare, since it can result in sensory losses or extreme distortions, including perceiving most touch information as pain. Early research in sensation and perception by the Gestalt school of thought resulted in the discovery that certain perceptual principles are largely innate.