Science News reports:

Everyone knows that the brain influences the heart.

Stressful thoughts can set the heart pounding, sometimes with such deep force that we worry people can hear it. Anxiety can trigger the irregular skittering of atrial fibrillation. In more extreme and rarer cases, emotional turmoil from a shock — the death of a loved one, a cancer diagnosis, an intense argument — can trigger a syndrome that mimics a heart attack.

But not everyone knows that the heart talks back.

Powerful signals travel from the heart to the brain, affecting our perceptions, decisions and mental health. And the heart is not alone in talking back. Other organs also send mysterious signals to the brain in ways that scientists are just beginning to tease apart.

A bodywide perspective that seeks to understand our biology and behavior is relatively new, leaving lots of big, basic questions. The complexities of brain-body interactions are “only matched by our ignorance of their organization,” says Peter Strick, a neuroscientist at the University of Pittsburgh.

Exploring the relationships between the heart, other organs and the brain isn’t just fascinating anatomy. A deeper understanding of how we sense and use signals from inside our bodies — a growing field called interoception — may point to new treatments for disorders such as anxiety.

“We have forgotten that interactions with the internal world are probably as important as interactions with the external world,” says cognitive neuroscientist Catherine Tallon-Baudry of École Normale Supérieure in Paris.

These internal signals, most of which we are wholly unaware of, may even hold clues to one of the grandest scientific puzzles of all — what drives human consciousness. [Continue reading…]