Nonnociception

Nonnociception is a term used to refer to sensory processing that does not involve nociceptors or the neural encoding of harmful or potentially harmful stimuli. In practice, it encompasses non-noxious somatosensory modalities such as light touch, proprioception, vibration, and non-noxious temperature, as well as sensory information from other systems that does not trigger pain. The term is not universally standardized, and in many contexts researchers refer instead to non-nociceptive somatosensory processing.

Nociception and pain are related but distinct concepts. Nociception describes the transmission of signals from peripheral receptors responding to noxious stimuli, while pain is the subjective experience that may or may not accompany nociception. Nonnociception, by contrast, refers to processing of information that is not inherently linked to pain signaling.

Non-nociceptive information typically travels via different pathways than nociceptive signals. For example, touch and proprioception use large-diameter Aβ fibers that ascend through the dorsal columns to the thalamus and somatosensory cortex, while nociceptive signals travel via the spinothalamic tract. Central processing can modulate pain, so non-nociceptive inputs can influence pain perception through attention, expectation, and context.

Clinically, the study of non-nociceptive systems supports diagnosis of sensory disorders (e.g., loss of vibration or proprioception indicating dorsal column dysfunction) and informs rehabilitation and prosthetics design. In research, non-nociceptive pathways are often studied to understand baseline sensory processing and how it interacts with pain pathways in health and disease.