Insula
Cerebral Cortex · Insular Cortex (Lateral Sulcus)
Side view
Tucked out of sight within the lateral sulcus, folded beneath the frontal, temporal, and parietal lobes, the insula integrates signals from inside the body - heartbeat, breathing, gut sensations - with emotional and social awareness.
Interoception, emotional awareness, social cognition
Insular Cortex (Lateral Sulcus)
The insula is sometimes called the brain's "hidden lobe" because it's completely covered by folds of the frontal, temporal, and parietal lobes and isn't visible at all from the brain's outer surface.
Anatomy & Location
The insula lies folded deep within the lateral sulcus, the same groove that separates the frontal and parietal lobes above from the temporal lobe below. Those surrounding lobes fold over and completely cover it, so unlike the four major lobes it has no exposed surface - it can only be seen by gently separating the folds around it. It's commonly divided into an anterior and a posterior portion, which differ somewhat in function.
Function in Depth
The insula's central job is interoception: continuously mapping the internal state of the body - heartbeat, breathing, gut activity, pain, temperature - and making that information available to conscious awareness. This gives it an unusually direct hand in emotion, since many emotional states are experienced partly as bodily sensations; the insula is one of the most consistently activated regions in brain-imaging studies of disgust, in particular. Beyond interoception, the insula contributes to taste processing, cravings and addiction-related urges, and - especially in its anterior portion - social and empathic processing, including recognising emotions in others.
Notable Research & History
Much of the modern understanding of the insula's role comes from neuroimaging and lesion studies from the 1990s onward, including influential work by neuroscientist Bud Craig mapping how interoceptive signals travel from the body through the brain stem and thalamus to the insula, and a 2000 case study by Andrew Calder and colleagues of a patient with damage to the insula and nearby basal ganglia, who had a selectively blunted ability both to feel disgust and to recognise it in others' faces, while recognition of other emotions remained largely intact. This research helped establish the insula as a genuine hub linking bodily state to subjective feeling, rather than a purely sensory way station.
When Something Goes Wrong
Differences in insula structure, activity, and connectivity have been studied in several conditions involving atypical emotional or interoceptive processing, including autism spectrum disorder, where some research links insula function to differences in interoceptive awareness and social-emotional processing. The insula is also heavily implicated in addiction, where craving is thought to partly reflect insula-driven interoceptive prediction, and in anxiety, where heightened interoceptive sensitivity can amplify awareness of normal bodily sensations like a racing heart.
Role in Everyday Abilities
The insula works with other regions to make these abilities possible:
- Emotion: Senses the body's internal state - heartbeat, breathing, gut feelings - and helps turn it into the conscious feeling of an emotion.
Related Conditions
The insula is discussed in connection with the following conditions on this site:
This article is for general education and isn't a substitute for professional medical advice. See our Terms of Use.
Sources & Further Reading
- Brain Basics: Know Your Brain - National Institute of Neurological Disorders and Stroke
- How do you feel? Interoception: the sense of the physiological condition of the body - Craig (2002), Nature Reviews Neuroscience
- Impaired recognition and experience of disgust following brain injury - Calder et al. (2000), Nature Neuroscience