The senses and the brain

The senses are the means by which the body gathers information about its surroundings and its own internal state. The five traditionally recognised senses are sight, hearing, smell, taste and touch, each served by specialised sensory organs and receptor cells. These receptors detect a particular kind of stimulus — light, sound, chemicals, pressure or temperature — and convert it into electrical nerve impulses, a process well suited to animation because it links a physical event to an invisible signal.

Each sense relies on dedicated structures. The eye detects light and forms images on the retina; the ear converts sound vibrations into nerve signals in the cochlea, and also helps with balance. The nose contains receptors that respond to airborne chemicals, producing the sense of smell, while taste receptors on the tongue respond to dissolved chemicals in food. The skin contains receptors for touch, pressure, temperature and pain spread across the body's surface.

All of these signals travel along the nervous system to the brain, which interprets them and builds a unified picture of the world. Different regions of the brain process information from different senses, and the brain often combines several inputs at once — for example, smell and taste together create the experience of flavour. The senses also trigger reflexes and guide behaviour, allowing the body to respond quickly to opportunities and dangers in its environment.

Frequently asked questions

What are the five traditional senses?

Sight, hearing, smell, taste and touch, each detected by specialised sensory organs and receptor cells.

How do sense organs communicate with the brain?

Receptors convert a stimulus such as light or sound into electrical nerve impulses, which travel through the nervous system to the brain for interpretation.

Why are smell and taste closely linked?

Both detect chemicals, and the brain combines their signals, so much of what is perceived as the flavour of food actually comes from smell.