![[Two red heartbeat waves extend from a black-and-white outline of a brain.]](https://blogs.iu.edu/sciu/files/2022/12/sciu_hrv_mainimage.png)
A healthy heart is not a metronome. Even though most of us can follow our heartbeat with ease, in between each heartbeat is a period of time that varies in duration from one beat to the next. This difference in time between any consecutive heartbeat is known as heart rate variability (HRV), and researchers are increasingly using it as a tool to understand mental health…