The insula is another name given to the area of the brain known as the insular cortex, the tissue surrounding the largest portion of the brain. Other names for this structure include insular lobe or insulary cortex. The insula is part of the cerebral cortex and helps to regulate emotion and works to assist in motor control function.
The insula has been clinically divided into two separate sections, anterior and posterior. Each of these sections is responsible for a diverse number of functions within the human body. The body’s ability to maintain a constant temperature, a state known has homeostasis, is linked to this area of the brain. Perception and self-awareness are also linked to the insula. Other functions influenced by the insula include cognitive function as well as motor control.
Body functions known as interoceptive awareness is regulated by the insula. Some of these functions include the timing of a person’s heartbeat as well as blood pressure control. The perception of pain is controlled to a limited degree by the insula, as is the feeling of having a full bladder. Certain perceptions also fall into the interoceptive awareness category, including feelings of empathy and the ability to passively listen to music.
Some motor skills are partially controlled by the insula as well. Speech and the ability to swallow are among these functions. This area of the brain has also been proven to assist in the recovery of motor skills following a traumatic event such as a stroke.
Some social emotions have been found to be profoundly influenced by the insula. These include feelings of disgust when witnessing violent scenes or smelling something that one deems foul. These emotions can also be triggered merely by the act of imagining such distasteful situations.
The insula can be negatively affected by a variety of diseases and disorders, such as Huntington’s disease. This area of the brain is widely believed to play a role in the presence of anxiety disorders as well as in the inability to regulate emotions. Alzheimer’s disease and other forms of dementia often affect this area of the brain as well. This is due to a condition known as hypometabolism, which is a decrease in the metabolic rate, or the amount of energy the body uses while at rest. Traumatic brain injuries as well as other diseases or medical conditions can also have an adverse effect on this area of the brain, requiring medical supervision and treatment.