How the Heartbeat Responds to a Surprise in the Environment

Matsuya and her team have devised a protocol which measures how the heartbeat responds to a surprise in the surrounding environment. It works in comatose patients, but also healthy participants in deep sleep that they sometimes use as a model for coma. What we found is that when a sound is omitted unexpectedly, no matter whether you are unconscious because you are in a coma, the heartbeat slows down only when the sound is omitted during a sequence where sounds were playing in synchrony with the heartbeat. So, it is as your heartbeat knows that something is changing in the environment and the signal is really easy to measure. We don't know exactly why this is happening. But this is certainly happening in a