SPOILER ALERT! ~ The anterior insula cortex is involved in the processing of basic emotions and social emotions ~ It is like a processing center where information from the body is put together to determine a course of action - in this case an emotion ~ When it malfunctions, it contributes to anxiety, especially in situations of uncertainty
Investigations in the fields of neuroimaging and neuropsychology implicate the anterior insular cortex in the processing of emotions. Investigating basic emotions such as anger, sadness, or disgust reveal activation in dorsal (i.e., back) and ventral (i.e., front) portions of the anterior insular cortex along with the amygdala and the ventral striatum.
Role of the anterior insula cortex
The anterior insular (AI) cortex is located deep within the lateral sulcus, and as a result it is not visible from the surface view. It has connections with other brain regions in the limbic system (i.e., emotional center) and frontal cortex (i.e., reasoning, judgment and calculation)
This layout represents the anatomical foundation for the integration of autonomic (i.e, involuntary body functions like blood flow, heartbeat, breathing, and digestion), viscerosensory (i.e, conscious sensations like bloating and nausea) and visceromotor functions (i.e., involuntary movements of smooth muscles, cardiac muscles, and glands) involving AI .
In addition to its role in the processing of basic emotions, studies in social neuroscience highlight its importance for social emotions
Reports indicate that the anterior insula (AI) is activated both when we experience pain in ourselves and when we observe it in others. Those results support the hypothesis that in order to share the emotions of others, neural structures that are involved in the direct experience of those emotions are recruited. That is the neural foundation of empathy.
The involvement of overlapping brain structures in empathy is emphasized in simulation theory. Based in cognitive science (i.e., study of thought, learning and mental organization), this theory proposes that we understand others’ mind by using our own mental states to simulate how we might feel or what we might think in a given situation, inferring from that what the other is actually feeling or thinking.
Positive social emotions
The AI is also recruited during positive, approach-related emotions such as love, attraction and compassion. Studies with those emotions reveal interesting findings, particularly the existence of a delayed response when processing those emotions compared to that which occurs when observing pain on others.
This finding suggests that processing of positive emotions such as compassion, admiration and virtue, requires spending more time evaluating the context and searching through our repertoire of socially learned responses before being able to feel that particular emotion.
Cooperation is another social emotion that recruits the anterior insula cortex, especially when it pertains to fairness. For example, MRI studies show that the degree of activation of AI corresponds to the amount of unfairness in a situation where cooperation is evaluated. In other words, the more unfair a situation was, the more heightened the activation of AI was observed, which suggests a role for AI in social decision making.
Conversely, the dysfunctional patterns of AI activity observed in patients with borderline personality disorder reflect their inability to maintain cooperation and repair broken cooperation.
Evidence has also accumulated for a role of AI in interoceptive awareness in affective processing. Notably, AI activation is associated with integrating bodily sensations to generate a corresponding emotion after appraisal. This means that the perception of a stomach cramp for example could translate into either fear or excitement depending on the context and past experience (e.g., if you have a stomach cramp while walking in a dark alley alone at night, you are more likely to experience fear than excitement).
Anxiety and uncertainty
By extension, malfunction of this system is believed to underlie anxiety as well. Indeed, anxiety arises from a mismatch between anticipated and experienced bodily responses to an aversive stimulus. Supporting this view, studies show increased activation of AI during emotion processing among individuals prone to anxiety.
Furthermore, recent reports indicate that the amygdala and the anterior insula cortex are greatly activated in response to aversive pictures (e.g., mutilated bodies, attack scenes, etc.) in a condition of uncertainty, that is when the participants were uncertain if the next displayed picture was going to be aversive or not. This implicates a role for AI in monitoring uncertainty and weighing risks.
Lamm C, Singer T. The role of anterior insular cortex in social emotions. Brain Struct Funct. 2010 Jun;214(5-6):579-91. doi: 10.1007/s00429-010-0251-3. Epub 2010 Apr 29. PMID: 20428887.