Tucked away in the brain’s complex folds is the insular cortex, a region involved in processes ranging from bodily regulation to complex emotional experiences. While the insula exists in both hemispheres of the brain, this article will explore the functions attributed to the right insular cortex. It serves as a hub for monitoring our internal world and shaping how we feel and interact with our environment.
Where is the Right Insular Cortex and What Does It Look Like?
The right insular cortex is a portion of the cerebral cortex located deep within the lateral sulcus, a prominent fissure that separates the temporal lobe from the frontal and parietal lobes. Because it is hidden from a surface view of the brain, it is sometimes referred to as a “hidden lobe.” To see it, one would need to pull back the overlying portions of the frontal, parietal, and temporal lobes, which are known as the opercula.
This structure is roughly shaped like a pyramid and makes up about 2% of the brain’s total cortical surface area. The insula is divided into two main parts by a deep crease called the central sulcus of the insula: a larger anterior insula and a smaller posterior insula. The anterior portion is characterized by three or four short, folded ridges known as gyri, while the posterior part consists of two long gyri.
The right insula is not an isolated island; it is intricately connected to many other brain regions. Its anterior part has strong connections with limbic areas involved in emotion and memory, such as the amygdala and orbitofrontal cortex. The posterior part primarily receives and sends signals to sensory and motor areas. This dense network of connections allows the right insula to integrate information from different sources, a feature fundamental to its functions.
The Right Insular Cortex as Your Body’s Internal Sensor
A primary function of the right insular cortex is interoception, the brain’s ability to sense and interpret the internal condition of the body. It acts as a monitoring station, receiving a constant stream of signals from the body’s organs and tissues. These signals convey information about heart rate, breathing, body temperature, pain, and muscle tension. This process allows for the conscious awareness of our internal bodily state.
This capacity is central to maintaining homeostasis, the process by which the body keeps its internal systems stable. For example, the right insula helps you recognize the feeling of thirst when your body needs water or the sense of fatigue when you need rest. It processes these internal cues, bringing them to your attention so you can take appropriate action. Studies have shown the right anterior insula becomes active when people focus on their own heartbeat, and its size has been correlated with how accurately a person can perceive these signals.
The flow of information begins with sensory nerves that send signals up through the brainstem to the thalamus. From the thalamus, these interoceptive signals are relayed to the posterior insula, where a basic map of the body’s condition is formed. This information then travels to the mid and anterior portions of the insula for further processing. This creates a more complete and subjective sense of your body’s overall state.
How the Right Insular Cortex Shapes Our Emotional Landscape
The right insular cortex plays a part in translating our internal bodily sensations into subjective emotional experiences. It serves as a bridge between what the body is feeling and how we emotionally interpret those feelings. This integration is why a racing heart and tense muscles can be experienced as excitement or anxiety, depending on the context. The right insula helps generate the conscious feelings tied to these physiological states.
This brain region is particularly associated with processing certain social emotions and negative feelings. Neuroimaging studies show activation in the right anterior insula during experiences of empathy, especially when observing the pain of others. This suggests it helps us simulate or share the feelings of another person. It is also involved in the emotion of disgust, whether it is a reaction to a bad smell or the sight of something unsettling.
The right insula’s activity is linked to our ability to navigate complex social situations. It contributes to feelings of compassion and our sense of fairness during interpersonal interactions. Some research indicates a hemispheric difference in emotional processing. The right insula is more engaged during negative emotional states, while the left is more broadly activated across both positive and negative emotions.
When Things Go Wrong: The Right Insular Cortex and Health Conditions
Dysfunction in the right insular cortex is implicated in health conditions involving altered emotional and internal body-state processing. Since this region is tied to interoception, problems here can disrupt a person’s ability to accurately perceive their body’s signals. This is a feature in anxiety disorders, where hyperactivity in the insula has been observed in individuals with panic disorder, phobias, and PTSD. An overactive insula might misinterpret benign bodily sensations as a sign of danger, triggering a panic attack.
The right insula also has a role in addiction. Research has shown that smokers who suffer brain damage to the insula, such as from a stroke, are significantly more likely to quit smoking easily and without relapse. This suggests the right insula is involved in creating the conscious urges and cravings associated with drug use. It links environmental cues with the memory of the drug’s physical effects.
Beyond anxiety and addiction, atypical function in the right insula is linked to other conditions. Difficulties with emotional regulation, decision-making, and social behavior can arise from damage or dysfunction in this area. In some cases of depression and eating disorders, abnormal activity in the mid-insula has been noted. This occurs during tasks that require focusing on internal bodily signals, underscoring its connection to mental and physical well-being.