Senses

Sense, in biology, refers to the ability to detect and respond to stimuli from the environment or from within the body. In humans, the traditional five senses—sight, hearing, taste, smell, and touch—provide a broad framework for how we perceive the world. These senses rely on specialized sensory organs and receptor cells that convert physical or chemical stimuli into neural signals that reach the brain.

Many scientists recognize additional senses beyond the classic five. The vestibular system provides balance and spatial orientation; proprioception informs body position and movement; nociception detects harmful stimuli and underpins the experience of pain; thermoception senses temperature. Some definitions also include interoception, which monitors internal states such as hunger, thirst, and heart rate. In various species, other specialized senses such as magnetoreception or echolocation exist.

Sensory information is carried by peripheral nerves to specific brain regions. Vision uses the eyes and the visual cortex in the occipital lobe; audition uses the ears and the auditory cortex in the temporal lobe; olfaction and gustation project to olfactory and gustatory pathways with cortical associations. Somatosensory signals arrive in the somatosensory cortex, while multisensory integration occurs across association areas, allowing perceptions to reflect context, attention, and prior experience.

Perception is not a direct copy of stimuli but an interpretation formed by the brain. Thresholds describe the limits of detection and discrimination. Senses can adapt over time and may decline with age or due to disease. The study of senses spans physiology, psychology, and neuroscience and informs fields from medicine to human–computer interaction.