Neuroscience lessons in body awareness from the man with two hearts

Researchers have been taking a keen interest lately in how the brain represents the internal state of the body - a process called interoceptive awareness (IA). There's evidence that poor IA is associated with eating disorders and other mental illnesses, and also that IA is important for social cognition, including empathising with other people. The most popular measure of IA is a person's sensitivity to their own heart beat - a topic we've covered on the Digest before. Neuroscientists think we detect our own heart-beats via two routes - one is "somatosensory"; that is, we feel the movement of the heart's beat in our skin and this information is processed in the part of the brain that deals with touch. The other route is "vagal", based on fibres that feed directly from receptors in the heart to the brainstem and then onto two brain areas known to be vital for IA: the insular cortex and the anterior cingulate cortex. Now a study led by Blas Couto and Agustin Ibanez and their colleagues, at the University of Cambridge and INECO, has explored this theory by testing a male patient "with two hearts". The 32-year-old man has a heart condition and is awaiting a transplant. In the meantime he has been fitted with a "left ventricular assist device" (see pic). This is an external pump that aids his failing left ventricle. Approximately the size of a large watch, it sits on his abdomen. Crucially, the frequency of this external pump is out of sync with the man's own...
Source: BPS RESEARCH DIGEST - Category: Psychiatrists and Psychologists Authors: Source Type: blogs