The Insula is a small lobe of the cerebral cortex that developed in primates and humans, and is concerned with consciousness, self-awareness, cognition and empathy, as well as some autonomic functions.
The insula is a small lobe of cortex found deep beneath the lateral sulcus. The cortex of the insula is continuous with that of the roof and floor of the lateral sulcus. It has been diveded into different areas with different functions, and is thought to be involved in social interactions.
Its functions include an involvement in autonomic control, and certain higher functions of the primate and human nervous system, such as self-awareness and empathy.
Key Words: Insula, nociception, autonomic control, social interactions, empathy.
The Insula - the hidden lobe of the cerebral cortex
Image source: clinicalpsychreading.blogspot.com
This diagram shows the position of the Insula, which can be divided into two by a vertical sulcus.
The Insula and Psychobiology
The human insula is hidden in the depth of the Sylvian (lateral) fissure with an area of less than 2% of the cerebral cortex.
It has afferent input from some sensory thalamic nuclei, and is connected with the amygdala and many areas of association cortex, including the limbic system.
It can be divided into different areas with widely different functions, including pain perception, speech, autonomic control, cognition and the processing of social interactions, involving self-awareness and empathy.
The insular cortex has passed through a spectacular progressive differentiation during the evolution of primates and humans. The insula contains some large spindle-shaped cells in layer V known as von Economo neurons (VENs) or mirror neurones.
Mirror neurons respond to the actions we observe in others - they become active when you perform an action and also when you see or hear others performing the same action. They are a variety of visuospatial neurons concerned fundamentally about social interaction. These neurons could help explain how and why we "read" the situations experiences by other people, and feel empathy for them.
If watching an action and performing that action can activate the same neurones, then it makes sense that watching an action and performing an action could also elicit the same feelings.
Mirror neurons become active both when you see someone upset and when you yourself feel upset, which may explain how we have the seemingly unique ability to empathise. Damaged mirror neurons could be associate with autism, a condition in which patients find it hard to empathise and socialise.
The reciprocal connections of the insula and amygdala provide for emotional responses experienced when observing the situation of others.