Interoception is the collection of senses providing information to the organism about the internal state of the body. This can be both conscious and subconscious. It encompasses the brain's process of integrating signals relayed from the body into specific subregions—like the brainstem, thalamus, insula, somatosensory, and anterior cingulate cortex—allowing for a complex and highly accurate representation of the physiological state of the body. This is important for maintaining homeostatic conditions in the body and, potentially, facilitating self-awareness.
Interoceptive signals are projected to the brain via a diversity of neural pathways, in particular from the lamina I of the spinal cord along the spinothalamic pathway and through the projections of the solitary nucleus, that allow for the sensory processing and prediction of internal bodily states. Misrepresentations of internal states, or a disconnect between the body's signals and the brain's interpretation and prediction of those signals, have been suggested to underlie conditions such as anxiety, depression, panic disorder, anorexia nervosa, bulimia nervosa, posttraumatic stress disorder (PTSD), obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), alexithymia, somatic symptom disorder, and illness anxiety disorder.