Editing Trigeminal nerve (section)

===Sensation===
{{Main|Somatosensory system}}
The two basic types of sensation are touch-position and pain-temperature. Touch-position input comes to attention immediately, but pain-temperature input reaches the level of consciousness after a delay; when a person steps on a pin, the awareness of stepping on something is immediate but the pain associated with it is delayed.

Touch-position information is generally carried by myelinated (fast-conducting) nerve fibers, and pain-temperature information by unmyelinated (slow-conducting) fibers. The primary sensory receptors for touch-position ([[Meissner’s corpuscles|Meissner's corpuscles]], [[Merkel's receptors]], [[Pacinian corpuscles]], [[Ruffini’s corpuscles|Ruffini's corpuscles]], [[hair receptors]], [[muscle spindle organs]] and [[Golgi tendon organs]]) are structurally more complex than those for pain-temperature, which are nerve endings.

Sensation in this context refers to the conscious perception of touch-position and pain-temperature information, rather than the [[special senses]] (smell, sight, taste, hearing and balance) processed by different cranial nerves and sent to the cerebral cortex through different pathways. The perception of magnetic fields, electrical fields, low-frequency vibrations and infrared radiation by some nonhuman vertebrates is processed by their equivalent of the fifth cranial nerve.

Touch in this context refers to the perception of detailed, localized tactile information, such as [[two-point discrimination]] (the difference between touching one point and two closely spaced points) or the difference between coarse, medium or fine sandpaper. People without touch-position perception can feel the surface of their bodies and perceive touch in a broad sense, but they lack perceptual detail.

Position, in this context, refers to conscious [[proprioception]]. Proprioceptors (muscle spindle and Golgi tendon organs) provide information about joint position and muscle movement. Although much of this information is processed at an unconscious level (primarily by the [[cerebellum]] and the [[Vestibular system|vestibular]] nuclei), some is available at a conscious level.

Touch-position and pain-temperature sensations are processed by different pathways in the central nervous system. This hard-wired distinction is maintained up to the cerebral cortex. Within the cerebral cortex, sensations are linked with other cortical areas.