I Feel, Therefore, I am: The Insula and Its Role in Human Emotion, Cognition and the Sensory-Motor System

Background: The insula is instrumental in integrating the emotional, cognitive, and sensory-motor systems. This manuscript lays a foundational framework for understanding the insula's mechanistic role in moderating brain networks in illness and wellness. Methods: Reviewed here is the select literature on the brain anatomy and function relevant to the insula's role in psychiatrically ill and normative populations. Results: The insula is a hub for moderating social cognition, empathy, reward-driven decision-making, arousal, reactivity to emotional stimuli, and somatic pain processing. Findings indicate a spectrum of increasing complexity in insular function - from receiving and interpreting sensorimotor sensations in the posterior insula to subjective perception of emotions in the anterior insula. The insula plays a key role at the interface of cognitive and emotional domains, functioning in concert with other brain regions that share common cytoarchitecture, such as the ventrolateral prefrontal cortex and the anterior cingulate cortex. Pharmacotherapy and mindfulness-based interventions can alter insular activation. Conclusion: The insula serves as a receiver and interpreter of emotions in the context of cognitive and sensory-motor information. Therefore, insular function and connectivity may potentially be utilized as a biomarker for treatment selection and outcome.